1997 Iowa Turfgrass Research Report D epartm ent of Horticulture Department of Plant Pathology Department of Entomology Cooperative Extension IOWA STATE UNIVERSITY In Cooperation with the Iowa Turfgrass Institute Io w a S t a t e U n i v e r s i t y University Extension Ames, Iowa BEARD COLLECTION FG-465 IJuly 1997 1 Welcome to the Iowa Turfgrass Field Day August 14, 1997 l 1 I Sponsored by: Department of Horticulture Cooperative Extension Iowa State University and Iowa Turfgrass Institute Field Day Program 9:15 a.m. Introductory Remarks - Registration Tent 9:30 a.m. CHOICE OF TWO TOURS Tour #1 Tour Research Plots 1. Trouble Shooting Clinic —Dr. Donald Lewis and Ms. Paula Flynn 2. Tree Care —Dr. Jeff lies 3. Rubber Topdressing —Mr. Jeff S almond 4. Dollar Spot Trial —Dr. Mark Gleason 5. Tall Fescue NTEP Variety Trials —Mr. Jim Dickson 6. Herbicide Trials —Dr. Nick Christians 7. Fertilizer Trials —Dr. Barbara Bingaman 8. Shade Trial —Dr. Mohamad Khan Tour #2 Golf Course Superintendent & Sports Turf Manager Tour — Dr. Dave Minner and Mr. Gary Peterson r This tour highlights the following research and demonstration areas: -SubAir demonstration - rootzone temperature control with air and circulated water -Topdressing with rubber to reduce turf damage under intense traffic (Mr. Jeff Salmond) -SportGrass - a combination of synthetic turf and real grass -Sloped green study - IGCSA and GCSAA project -Sand green amendment study (Dr. Young Joo) -Fertility for establishing bentgrass on sand-based greens (Mr. Mike Faust) -High-traffic Kentucky bluegrass variety trial -NTEP bentgrass variety trial - putting green and fairway. 12:00 noon 1:30 p.m. Lunch and Visit with Exhibitors Educational Sessions and Demonstrations ♦ Pesticide Recertification Cont. Ed. Course (2 hours) —Main Building ♦ Natural Herbicide Research Update —Dr. Nick Christians ♦ Türf I.D. and Weed, Disease & Insect Control Tour —Dr. Dave M inner ♦ Equipment Demonstration —Equipment Display Area —Mr. Jim Dickson ♦ SubAir Demonstration —Mr. Jeff Salmond ii Manhattan P. Rye Tall F escue Wildflower Native Grass Establishment Study |o h u Vantage KBG Parade KBG Ram I KBG Park KBG Com Gluten Weed Control Trial Com Gluten Weed Control Trial Com Gluten Weed Control Trial Glade KBG u IT, g£ 'I 1 2 g 1® 261,360 ft 6.0 Acres High Maintenance Bluegrass 1995 Envy P.Rye Introduction Nick E. Christians and David D. Minner The following research report is the 18th yearly publication of the results of turfgrass research projects performed at Iowa State University. Copies of information in earlier reports are available from most of the county extension offices in Iowa. This is the first year that the entire report is available on the Internet. It can be accessed at: http://www.hort.iastate.edu/hort/Frames/pubs/pframe.html The 1996 season will be remembered for the severe winter desiccation that occurred during the winter of 95-96. The summer and fall of 1996 provided very good conditions for the growth of grass. For the 7th year, this research report contains a section titled "Environmental Research." This section is included to inform the public of our many research projects that are aimed at the environmental issues that face our turf industry. Several new sand-based golf and athletic field research plots are under construction on the south end of the Turf Facility at the Horticulture Research Station. Various products and technologies associated with sand-based systems will be evaluated such as: SportGrass - a combination of natural grass and synthetic turf, Heatway - a water circulated soil heating system, SubAir - a subsurface forced air system, several organic and inorganic sand amendments, and a sloped area to study temperature and moisture stress on putting greens. We would like to acknowledge Richard Moore, superintendent of the ISU Horticulture Research Station; Jim Dickson, manager of the turf research area; Barbara Bingaman, Postdoctoral researcher; Doug Campbell, research associate; Jeff Salmond and Mike Faust, graduate students; John Jordan, field technician and all others employed at the field research area in the past year for their efforts in building the turf program. Special thanks to Lois Benning for her work in typing and helping to edit this publication. Edited by Nick Christians and David Minner, Iowa State University, Department of Horticulture, Ames, IA 50011-1100. Dr. Nick Christians Phone: 515/294-0036 Fax: 515/294-0730 E-mail: nchris@iastate.edu Dr. David Minner Phone: 515/294-5726 Fax: 515-294-0730 E-mail: dminner@iastate.edu Table of Contents Environmental Data............. ........................................................................................................... 1 Species and Cultivar Trials Results of Regional Kentucky Bluegrass Cultivar Trials........................................................... 5 1995 Kentucky Bluegrass Cultivar Trial - High Maintenance, High Traffic........................ 9 Regional Tall Fescue Cultivar Evaluation.................................................................................. 13 Regional Fine Fescue Cultivar Evaluation.................................................................................. 15 Perennial Ryegrass Study............................................................................................................. 17 Shade Adaptation Studies............................................................................................................. 20 Fairway Height Bentgrass Study.................................................................................................. 23 Green Height Bentgrass Cultivar Trial (Native Soil)................................................................. 24 Herbicide and Growth Regulator Studies Pre- and Postemergence Annual Weed Control Study.............................................................. 25 Postemergence Annual Weed Control Study............................................................................. 31 1995 Poa annua Control in Creeping Bentgrass Greens - Year 2 ........................................... 34 Effects of Trinexapac Ethyl on Sod Production....................................................................... 36 Effects of Trinexapac Ethyl (Primo) on Perennial Ryegrass Seedlings.................................. 38 The Effect of Betasan on Four Creeping Bentgrass Cultivars Maintained at Green Height... 41 The Effect of Tupersan on Four Creeping Bentgrass Cultivars Maintained at Fairway H eight................................................................................................................................... 43 Non-selective Herbicide Demonstration Study.......................................................................... 45 Turfgrass Disease Research Nutrient Salts and Toxicity of Black-layer................................................................................ 47 Evaluation of Fungicides for Control of Brown Patch in Creeping Bentgrass........................ 49 Evaluation of Fungicides for Control of Dollar Spot in Penncross Creeping Bentgrass......... 51 Evaluation of Fungicides for Control of Metalaxyl-resistant Pythium Blight on Creeping Bentgrass.............................................................................................................. 53 Fertilizer Trials and Soil Studies Kentucky Bluegrass Fertilizer Study............................................................................................ 55 Vigoro Kentucky Bluegrass Fertilizer Study............................................................................... 59 Response of Kentucky Bluegrass to Potassium......................................................................... 61 Toro Bentgrass Establishment Trial........................................................................................... 65 v Environm ental Research 1991 Com Gluten Meal Crabgrass Control Study - Year 6 ...................................................... 67 1995 Com Gluten Meal Rate Weed Control Study - Year 2 .................................................... 71 1995 Com Gluten Hydrolysate Weed Control Study - Year 2 .................................................. 75 Pendimethalin and Com Gluten Meal Combinations for Weed Control in Turfgrass............ 77 T u rf M anagement The Effects of De-icing Chemicals on Turfgrass - 1996 Trial................................................ 80 The Effects of De-icing Chemicals on Turfgrass - 1997 Trial................................................ 91 Establishing and Maintaining Turfgrass Over a Steam Line, 1996-97 Data............................ 94 Managing Cool-season Grasses as Part of a SportGrass® System.............................................. 100 Evaluating a Forced-air System for Sand Based Creeping Bentgrass Putting Greens............... 102 Rubber Tire Particles as a Topdressing Amendment for Intensely Trafficked Grass 1996 D ata............................................................................................................................ 104 The Effect of Topdressing with Rubber Buffings on Intensely Trafficked Football Turf...... 108 O rnam ental Studies Tree Planting Basics.................................................................................................................... 110 Crabapples: Sales Trends and Consumer Preferences in Iowa.................................................. 114 Crabapple Bloom Sequence and Length of Bloom Period in 1996........................................... 119 Introducing The Iowa State University personnel affiliated with the Turfgrass Research Program.......... 122 Companies and Organizations that made donations or supplied products to the Iowa State University Turfgrass Research Program............................................................................ 123 1 1 20 26 56 0 .2 5 30 28 1 29 32 26 27 i 66 ! 32 0 .0 5 28 j 27 47 60 Gv 04 Ì 1 o o o o O in 04 04 04 o O T— H OO o o O o © © 32 vo 04 o 26 27 28 29 30 O 23 27 23 27 ! o in VO O' OO OV 04 CO ^104 : - O 22 23 o o O o o o o o © vo CO in in CO CO 04 ! in VO 0- oo ov O O O O O'1 O 1 in Gs VO in vo in vo1 - O'i O' 1 1 33 34 49 59 36 29 44 53 36 22 1 29 1 o o o o 04 20 - 04 CO CO oo oo ; January © O O O O in in 04 04 0.4 0.02 o 04 28 Precipitation Tempe rature High Low (inches) 33 0.03 3o ; 32 ! 23 22 co o in co 1 04 40 o 04 co co OO 23 O 22 o co 24 i OOO 32 © © O © © 1 OO - O Oiv Oi 04i CO in 49 o in in VO to OO OV 04 co co 04 C4 OO O 04 co co 20 26 33 34 23 24 1 ! O' oo Gv o - OO OO oo i in VO o o o o coi o 25 30 04 co o to 26 r —H O 29 o o in 1m^ 04 04 45 O O in in 04 46 1 ooi O* oo— < 45 04 37 1— H 1 32 ! -3 0 Ì -2 3 Precipitation Tempe rature Low High (inches) (N o o O Ovo O Nm 00 oo V Ovo Or- vo C Oun un un V r- r- r- r- V ^- vo V oo oo oo O No r- oo un o en r- NO WO NO r- NO WO NO o- r- NO NO NO wo NO 04 o © OO ON o o oo ^r to o CO WO oo wo wo wo NO r- NO wo NO ^r NO o- oo o © O' oo o wo NO o- oo O n o T—H 04 CO or wo NO O' oo ON O 04 CO 04 04 04 04 04 04 04 04 04 04 CO CO 4 Species and Cultivar Trials Results of Regional Kentucky Bluegrass Cultivar Trials Nick E. Christians and James R. Dickson The United States Department of Agriculture (USDA) has sponsored several regional Kentucky bluegrass cultivar trials conducted at most of the northern agricultural experiment stations. Two trials were underway at Iowa State University during the 1996 season. The first, a highmaintenance study, was established in 1995, and received 4 lb N/1000 ft2/yr, and is irrigated as needed. The second trial was established in 1995 and received 1 lb N/1000 ft2/yr in September but was non-irrigated. They are mowed at two inches. The objective of the high-maintenance study was to investigate cultivar performance under a cultural regime similar to that used on irrigated home lawns in Iowa. The objective of the second study was to evaluate cultivars under conditions similar to those maintained in a park or school ground. The values listed under each month in Tables 1 and 2 are the averages of visual quality ratings made on three replicated plots for the two studies. Visual quality was based on a 9 to 1 scale: 9 = best quality, 6 = lowest acceptable quality, and 1 = poorest quality. Yearly means of monthly data were taken and are listed in the last column. The first cultivar received the highest average rating for the entire 1996 season. The cultivars are listed in descending order of average quality. Data for genetic color (Gcol), spring green-up (Gm), leaf texture (Leaf), and percentage spring ground cover (Scov) also are included for the high-maintenance, irrigated trial and the lowmaintenance trial. Table 1. The 1996 ratings for the 1995 high-maintenance, irrigated Kentucky bluegrass trial. Cultivar 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 Blacksburg H86-690 ZPS-2572 PST-B2-42 Award Limousine MED-1497 BAR VB 3115B Unique Baron Haga PST-BO-141 Baronie Challenger Midnight BAR VB 233 Ba 73-373 Bartitia Caliber Classic LKB-95 Gcol 6.0 8.0 6.0 7.3 7.3 6.7 7.0 5.7 6.3 6.7 6.7 7.7 5.7 6.7 6.7 6.0 7.0 6.0 6.3 6.7 5.0 Gm Leaf Scov May June July Aug Sept Oct Mean 6.3 6.0 ' 5.3 5.7 5.3 5.7 6.0 5.3 5.3 5.3 5.7 6.3 5.3 5.3 5.7 6.0 6.0 6.3 5.7 5.7 5.3 8.0 7.3 7.0 7.0 6.7 7.3 5.7 7.3 6.7 6.3 6.7 6.0 6.3 6.7 56.7 60.0 53.3 56.7 46.7 60.0 43.3 66.7 53.3 56.7 63.3 40.0 50.0 36.7 7.7 8.0 7.7 7.7 7.3 8.0 7.7 8.0 7.7 7.0 8.0 8.0 7.0 7.7 7.3 7.7 6.7 7.3 5.7 7.0 6.7 6.0 6.7 7.0 7.3 7.3 7.3 7.7 6.3 7.7 6.7 6.7 7.0 7.0 6.0 7.3 6.3 6.7 8.0 33.3 53.3 46.7 43.3 60.0 50.0 56.7 6.0 6.3 5.7 5.7 5.0 6.7 4.0 6.7 5.7 6.3 6.7 4.7 5.0 4.3 4.0 5.0 5.7 5.0 6.7 6.0 6.0 7.3 7.7 7.7 7.3 7.7 7.0 8.0 7.0 7.0 6.7 6.7 7.0 6.7 7.0 6.7 6.7 6.3 7.0 6.0 6.3 6.3 7.7 7.3 7.7 8.0 7.3 6.7 7.0 6.7 7.0 7.0 6.7 7.7 6.7 7.3 7.3 6.3 6.3 7.0 7.3 7.3 7.3 7.2 7.1 6.9 6.9 6.8 6.8 6.7 6.7 6.7 6.6 6.5 6.5 6.4 6.4 6.4 6.3 7.3 6.3 6.4 6.4 6.4 5 7.3 7.7 6.0 7.0 7.7 7.3 6.7 7.3 7.7 7.7 6.3 7.0 7.0 6.7 6.3 6.3 6.3 5.7 6.3 6.7 6.3 6.7 7.0 7.3 7.0 6.3 6.3 6.7 5.7 5.7 5.7 Species and Cultivar Trials 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 Cultivar Gcol Gm Leaf Scov May June July Aug Sept Oct Mean Shamrock Coventry 6.7 7.3 7.0 7.7 6.3 6.3 6.3 7.3 7.3 6.7 6.0 5.7 5.3 5.0 6.3 5.3 5.7 4.7 5.0 5.0 6.3 6.7 5.3 6.3 6.0 6.3 5.7 7.0 6.3 6.7 7.0 6.3 6.0 40.0 36.7 36.7 36.7 36.7 40.0 36.7 43.3 33.3 43.3 53.3 33.3 36.7 30.0 40.0 4.7 4.0 5.0 5.7 4.7 4.7 5.3 5.3 4.3 4.7 5.3 4.7 4.7 4.3 5.0 4.7 4.7 4.3 4.3 5.7 3.7 4.7 4.7 4.3 4.3 4.3 3.7 4.3 3.7 3.7 5.7 4.3 4.0 4.0 4.7 3.7 6.3 6.0 7.0 5.7 6.7 6.3 6.7 6.3 5.3 6.7 6.7 6.7 7.0 6.3 6.0 6.0 6.0 6.0 6.7 6.7 6.7 6.7 6.7 6.7 7.0 6.7 6.0 6.0 6.3 5.7 6.7 6.7 6.0 5.7 5.7 7.0 6.7 6.3 7.0 7.0 6.7 6.3 6.0 7.0 7.0 7.3 6.7 7.0 6.7 7.0 7.3 6.3 7.0 6.7 6.4 6.3 6.3 6.2 6.2 6.2 6.2 6.2 6.2 6.2 6.3 6.3 6.0 6.0 6.3 6.0 6.3 6.0 6.3 6.7 6.5 6.0 5.3 5.7 6.3 6.7 7.0 6.7 7.0 6.7 5.7 6.7 7.0 6.0 '6.3 7.3 6.0 6.1 6.1 6.1 6.1 6.1 6.1 6.1 6.1 6.0 6.0 5.9 5.9 5.9 5.9 5.9 5.9 5.9 5.9 5.8 5.8 5.8 5.8 5.8 5.8 5.8 J-1567 A88-744 Ba 81-220 Ba 81-270 NuStar Raven TCR-1738 ZPS-2183 Abbey Ba 70-060 Ba 81-058 J-1936 Jefferson MED-1991 Nimbus Pick 8 NuGlade Platini BAR VB 6820 Ba 79-260 Ba 81-113 Ba 87-102 Chateau MED-1580 NJ 1190 PST-638 J-1576 J-2579 Kenblue Marquis NJ-54 Princeton 105 SRX 2205 ZPS-309 America Ascot Ba 75-490 J-1561 PST-A7-245A PST-A7-60 PST-B3-180 Ba 76-197 HV 130 7.0 6.7 6.7 7.3 7.3 7.0 5.7 7.0 7.3 6.0 7.0 7.3 6.7 6.7 6.0 6.7 5.7 8.0 6.7 6.7 6.3 7.0 6.3 7.0 6.7 5.7 7.7 7.0 6.7 7.3 6.3 6.7 7.0 6.3 7.0 5.3 5.3 6.0 5.0 6.0 6.0 5.3 5.3 5.3 6.0 5.0 5.7 6.0 6.0 6.0 6.0 6.0 5.7 5.3 5.7 5.3 6.3 6.0 6.0 5.3 6.3 5.3 5.7 5.3 5.7 5.3 5.3 5.3 6.0 6.3 6.0 7.0 7.0 7.7 6.0 6.3 6.7 7.7 6.3 6.7 6.3 5.7 6.3 7.3 6.0 6.7 7.7 8.0 6.0 6.3 6.7 8.3 6.7 7.3 6.0 5.7 6.7 5.7 7.0 7.0 6.3 6.0 40.0 40.0 40.0 33.3 40.0 33.3 46.7 40.0 36.7 30.0 36.7 30.0 33.3 30.0 30.0 56.7 36.7 26.7 30.0 43.3 40.0 30.0 26.7 30.0 36.7 30.0 30.0 23.3 23.3 26.7 6 4.3 4.0 3.7 4.0 3.7 4.0 3.3 3.7 3.7 6.3 6.0 6.0 6.3 6.3 7.0 6.3 5.0 6.0 6.3 6.0 7.0 6.3 5.3 6.7 6.0 5.3 6.3 5.7 6.7 6.0 6.0 5.3 6.3 6.0 6.0 6.0 5.3 5.7 5.7 5.7 7.0 8.0 6.3 7.0 6.0 7.5 5.7 7.5 6.3 6.0 4.3 5.3 5.7 6.7 5.7 6.3 6.3 6.3 6.3 7.0 6.0 6.7 6.7 6.3 7.0 6.0 6.7 7.0 6.3 6.0 6.3 5.0 7.0 5.7 6.3 5.3 6.3 6.3 6.0 6.0 5.3 5.3 5.3 5.7 5.7 6.0 5.3 6.5 6.0 5.7 5.7 5.7 6.0 5.7 5.3 6.3 6.0 6.3 6.7 6.7 6.3 6.3 6.7 6.3 6.7 7.0 6.3 5.7 6.0 6.0 7.0 6.0 6.3 6.7 6.3 6.3 6.7 6.7 6.7 6.3 6.3 6.0 6.3 6.0 5.7 6.3 6.0 5.7 6.3 5.7 6.0 6.0 6.0 6.0 6.0 6.3 6.3 6.3 7.0 6.3 6.0 7.0 6.0 7.3 6.7 7.0 6.7 5.8 5.7 5.7 5.7 5.7 5.7 5.7 6.7 6.7 5.7 7.3 6.7 6.7 5.7 5.6 5.6 Species and Cultivar Trials Cultivar Gcol Gm Leaf Scov June July Aug Sept 6.3 5.0 6.7 5.7 5.7 5.0 6.3 30.0 3.7 6.3 5.7 26.7 5.3 5.0 6.0 6.3 6.3 3.3 6.7 3.0 5.3 5.7 6.0 6.3 5.3 6.3 30.0 6.7 6.0 5.7 5.7 5.7 5.7 33.3 4.0 5.3 6.0 7.0 5.7 6.3 5.3 7.0 33.3 3.3 5.3 5.7 8.0 5.7 5.0 30.0 3.7 5.0 6.7 5.3 6.0 5.3 5.3 5.7 7.0 5.3 7.0 36.7 5.3 3.0 5.3 6.0 5.7 6.0 7.0 6.0 7.0 23.3 5.0 6.0 6.3 7.0 6.0 6.3 30.0 4.0 5.3 6.7 3.7 5.7 5.3 5.7 7.0 5.7 6.7 30.0 5.7 5.7 6.3 5.7 6.3 33.3 4.0 6.0 5.3 5.3 6.0 6.7 7.7 33.3 4.0 6.3 5.3 5.3 5.7 7.0 5.3 7.0 26.7 3.7 4.7 6.7 5.3 6.0 6.0 3.0 4.7 7.0 5.7 6.0 6.0 23.3 5.7 6.0 7.3 5.7 5.3 20.0 3.0 4.7 5.7 7.0 6.0 5.7 30.0 4.0 4.3 6.0 5.3 6.3 5.0 6.5 7.5 6.3 6.7 6.3 26.7 3.3 5.3 6.0 6.3 7.3 5.3 6.7 20.0 3.0 4.7 5.7 5.0 5.7 7.0 6.0 6.3 26.7 3.3 5.0 6.5 Ba 75-173 5.3 6.7 5.7 5.7 23.3 3.3 4.7 6.0 5.0 Ba 81-227 6.3 6.7 5.7 7.0 20.0 3.3 4.7 6.0 6.0 HV 242 5.7 7.3 5.7 5.0 20.0 3.7 4.3 5.0 5.0 88 Ba 76-372 4.0 6.0 5.3 5.3 89 Conni 6.0 5.7 7.3 23.3 3.3 5.7 6.7 6.0 23.3 3.7 4.7 6.0 4.7 90 Eclipse 5.3 5.0 5.7 7.0 6.3 6.7 23.3 3.3 5.0 6.0 91 J-1555 6.7 5.3 26.7 2.7 5.0 5.0 5.3 6.0 92 Cardiff 6.3 5.5 5.3 5.7 5.3 5.3 5.0 16.7 3.3 4.3 93 Compact 5.0 6.0 94 Pic-855 7.0 5.3 6.3 26.7 4.7 4.7 3.3 8.0 6.0 5.7 4.7 5.3 95 VB 16015 5.3 33.3 3.7 4.3 4.0 5.3 96 Ba 77-702 7.0 4.7 5.7 20.0 2.7 6.5 4.7 7.7 5.7 8.0 30.0 5.0 5.7 4.3 5.0 97 Lipoa 3.3 6.7 6.0 6.0 16.7 3.0 4.0 4.5 6.0 5.7 98 SR 2109 7.7 5.3 5.3 16.7 3.7 4.3 5.0 5.3 99 Ba 75-163 2.3 5.7 100 DP 37-192 6.7 5.3 7.0 33.3 3.0 4.7 5.0 4.7 101 LTP-620 6.7 5.0 5.3 16.7 3.0 3.7 6.5 4.3 5.3 102 ZPS-429 6.7 5.7 6.0 26.7 4.0 4.7 5.5 5.5 5.5 4.7 103 PST-A418 8.0 6.3 5.0 13.3 2.0 2.7 6.5 3.7 3.0 2.7 1.5 3.1 1.3 44.5 4.6 3.5 3.1 LSD(oos) Quality based on a 9 to 1 scale: 9 = best quality, 6 = lowest acceptable quality, and 1 = poorest Gcol (Genetic color); Gm (Green-up); Leaf (Leaf texture); Scov (Spring ground cover) 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 J-2582 Livingston MED-18 PST-BO-165 Pick-3561 SR 2100 Wildwood Glade NJ-GD Sodnet BAR VB 5649 Baruzo Fortuna LTP-621 SR 2000 Sidekick Allure PST-P46 May 7 Oct Mean 6.7 7.3 7.0 6.7 6.0 7.3 6.0 7.0 6.3 6.0 6.0 5.3 6.3 7.7 7.3 6.7 6.5 6.0 6.7 7.0 5.7 5.6 5.6 5.6 5.6 5.6 5.6 5.6 5.5 5.5 5.5 5.4 5.4 5.4 5.4 5.4 5.4 5.3 5.3 5.2 5.2 5.2 5.1 5.1 5.1 5.1 5.0 4.9 4.9 4.9 4.8 4.8 4.8 4.6 4.6 4.5 4.4 6.7 6.3 6.7 6.3 6.3 5.7 6.0 5.7 6.3 5.7 6.3 6.7 4.7 7.0 6.5 7.3 4.3 1.6 2.5 quality. Species and Cultivar Trials Table 2. The 1996 ratings for the 1995 low-maintenance, non-irrigated Kentucky bluegrass trial. Cultivar 1 2 3 4 Gcol Gm Leaf Scov Eagleton Baronie Caliber BAR VB 233 Baron Kenblue BAR VB 3115B Canterbury May June July Aug Sept 6.7 7.0 7.0 80.0 7.7 7.7 6.3 7.3 7.3 6.3 8.0 7.3 70.0 7.0 7.7 6.3 7.0 7.0 6.7 8.0 7.0 60.0 6.7 7.3 6.3 6.0 7.0 6.7 6.7 7.3 53.3 6.0 7.7 5.7 6.0 7.7 7.0 8.0 7.0 5 56.7 6.0 6.3 6.0 7.0 7.0 6.0 6.7 6.7 70.0 6.0 6 7.3 6.3 6.7 6.7 7.0 6.3 6.7 7 43.3 5.0 6.7 5.3 6.0 6.7 7.0 7.0 7.0 46.7 8 5.0 5.7 5.0 6.3 6.3 6.3 7.7 9 Blue Star 7.3 43.3 4.7 6.3 5.7 6.0 6.0 6.7 6.3 6.0 36.7 5.3 6.0 10 South Dakota 5.3 5.7 6.0 6.7 7.7 7.0 4.7 11 BAR VB 5649 40.0 6.3 5.7 6.0 5.3 6.7 8.0 6.3 36.7 12 PST-A7-60 4.3 5.3 5.7 5.7 6.0 7.3 7.7 7.0 40.0 3.7 6.3 5.0 6.0 13 Bartitia 5.3 14 Baruzo 6.3 8.0 7.3 33.3 4.3 6.0 5.0 5.3 6.0 7.3 8.0 7.0 50.0 4.7 15 Lipoa 5.3 4.7 5.0 4.7 8.0 7.0 6.0 30.0 3.7 4.7 4.7 16 PST-B9-196 5.3 5.0 7.3 7.0 6.7 40.0 17 BH 95-199 3.0 4.7 4.0 4.3 6.0 6.0 7.7 6.7 18 MTT 683 33.3 3.3 5.7 4.3 4.7 4.7 7.3 7.7 7.3 26.7 3.3 4.7 4.3 4.7 4.3 19 ZPS-429 8.0 7.7 5.7 26.7 2.3 3.7 20 VB 16015 4.3 4.3 4.3 6.7 7.7 21 BAR VB 6820 6.7 20.0 2.0 3.3 2.7 3.0 3.0 1.4 1.5 1.6 18.8 1.7 1.2 1.7 1.7 1.8 L S D o os Quality based on a 9 to 1 scale: 9 = best quality, 6 = lowest acceptable quality, and 1 = poorest Gcol (Genetic color); Gm (Green-up); Leaf (Leaf texture); Scov (Spring ground cover) 8 Oct Mean 8.0 7.3 7.3 7.3 6.7 6.0 6.7 7.3 5.7 6.0 5.3 6.0 6.0 5.7 5.0 5.3 6.0 4.7 5.0 4.3 4.0 1.2 quality. 7.4 7.1 6.8 6.7 6.5 6.5 6.1 5.9 5.7 5.7 5.6 5.5 5.4 5.4 4.9 4.8 4.7 4.6 4.4 3.9 3.0 1.2 Species and Cultivar Trials NTEP 1995 Kentucky Bluegrass Cultivar Trial High Maintenance, High Traffic 1996 Progress Report David D. Minner The United States Department of Agriculture (USDA) has sponsored several regional Kentucky bluegrass cultivar trials conducted at most of the northern agricultural experiment stations. The current test consists of 103 cultivars. Each cultivar was replicated three times. This trial, a highmaintenance traffic study, was seeded in August, 1995, and received 4 lb N/1000 ft2/yr, and is irrigated as needed. The study is mowed at two inches. The objective of the high-maintenance study was to investigate cultivar performance under a cultural regime similar to that used on high-traffic areas in Iowa. Traffic treatment will begin in the summer of 1997 once plots are completely covered with grass. The values listed under each month in Table 1 are the averages of visual quality ratings made on three replicated plots. Visual quality was based on a 9 to 1 scale: 9 = best quality, 6 = lowest acceptable quality, and 1 = poorest quality. Yearly means of monthly data were taken and are listed in the last column. The first cultivar on the table received the highest average rating for the entire 1996 season. The cultivars are listed in descending order of average quality. Genetic color (Gcol), spring green-up (Grn), leaf texture (Leaf), spring density (Den), percentage spring ground cover (Scov), summer ground cover (Sucov), and fall ground cover (Fcov) data are included for the high-maintenance, irrigated traffic trial. 9 369 Mean Oct WO p © p 00 CO p p p 1— 1 o CO p 00 CO p p vo p p p p Os Os ON oo oo oo oo oo p p p p p p SO vq so so SO vq so p wo wo VO vo vo VO vo vo vo vo vo vd vd vd vd vd vd vd vd vd vd vd vd vd vd vd p p p p p vo vo p p p p p p p vd vo vd vd p p p p vd vd vd p p CO p p p p p vd vd vd vd vd vd June p 9 ll) CO p p o p p VO p p p VO VO o p p VO p p p p p vo i> vo C-7 p p p p i> vo p p p p p p p p p p p p VO vo vd vd vd vd vd vd vd vd vd p p p © p p p p p p p p p p p p p p p p p r- p p p p p VO VO vo 1> VO vo VO vo VO vo vo VO vd vd vd vd vd vo wo wo vd vd vd vd vd vd vd p p oo p p p CO p © p 00 p p r7 p p p CO CO p p o p vo p p p o p p p p p p p SO vd p p r-’ p p od p p p p p od p P CO p vd 1> p p p vd vd p CO p CO p p oo VO p p CO p p p p VD wo VO oo p p p p p p p p p p p p p p p p p VO VO wo VO oo vo wo VO vo vo vo wo vo wo vo vd p p p p p p vd vd vd vd vd p p p p p p WO vd vd vd p p p vd vd p p o p p p p p vd wo vd p p p p wo vd vd vd Sucov © p CO p p p P p P p O P p p p P P p p p o p p p p p O o p p p p p p p o vd wo CO CO oo © CO ^h' 00 vo VO vo _h‘ Ò VO VO OO od WO o WO CO od CO o O wo OO wo ^4 CO CO VO ON OO OO oo oo Os ON r- oo ON ON 00 00 OO 00 ON 00 OO 00 ON oo 1> r- oo OO ON 00 ON oo OO ON ON ON OO 00 Scov O p o p o CO p p p © p CO p wo oo 00 00 CO CO CO 00 © wo o rr - VO oo ON oo oo so VO ON O n Den p Leaf p p p p CO p p WO wo vd VO C"-' wo Gm p o o o p p p P p p p o r- p o p p p p p r- p p o p p o o p p p o p p p o ON oo ON ON ON ON ON vd ON Os Os so ON O n ON ON ON ON CN vo CN vo vd ON ON Os os Os os ON ON ON ON ON ON ON ON O n ON ON ON ON ON ON ON ON ON ON ON ON ON O n ON ON ON oo ON ON ON ON ON CO CO p p p p p p p p p p p p p p p wo wo wo wo wo wo wo VO VO VO VO vo wo VO WO wo vo vo WO wo wo wo WO wo wo wo wo wo wo vd vd WO wo wo wo vd Gcol 53 63 Sept Aug July © p p p CO p p p oo oo oo oo 1> oo Fcov p May 6 p CO CO CN CN 1> p CO CO p r-‘ CO CO CO p p oo VO p p 00 p p oo p p P p i> p p P P O p p p o O o CO wo [ CO © _4 CO od o o o 00 oo o ON oo so vo oo p p p p P p p p p wo wo vo vo vo vo vo p p p p p p od p p p p P o r -- p p P p o p p —i pm4 o vd CO CO Of 1-H o Of CO oo OO ON r- wo OO r^ r- r - r - p p od P p p p vd p p P p vd p p p p p p p p p p p p p p p p vo wo vo VO vo wo vd r> vd vd vd vd vd vd vd vd P p p vd vd p p o p vd vd vd vd 73 © CO p CO p p p p p CO p p p CO p p p CO p p p p p o p p p p p p p p p p p p wo od VO o ovd vd vd VO VO VO wo VO VO vo VO vo vd vd vd Ba 75-490 p p ppp pp pp p p pp p p pp pp o .S oC3 CN V3 oON o D» ' 3O *w • 4< — oo5 1C a °° 1 *■— 3 cd .S U u CQ J Ì Cultivar Visual quality1 Table 1. The 1996 quality ratings for the high-maintenance Kentucky bluegrass test. Traffic treatment will begin in 1997.________ Species and Cultivar Trials t M rnmv T t ^ >u ^ N o o f N^ ° '^H (^N c o ^t ' G^ \ O^ h ^O O^ C ^> 0 CN c c e c3 o U Of vo o of S? 4 CO ^ WO cd CN C cd 55 C3 o p 03 o i2 C/3 00 U— 1 c/o cu cu < z cu CQ Qh Z PQ U ni» nJ D CQ CJ X •— > cu cu 10 wo CO o oo rO wo C N cd /3 wo c U *C Ò D C^- oo r- 2 Oh o >< c/b r<-< cd cd 73 > p Pu Oh s ed cd CQ QQ W PC z N < CQ QQ — CN CO ^ f wo vo r - oo ON O — CN CO 'df wo vo r (N CN CN CN CN CN CN CN CN CO CO CO CO CO CO CO CO M ean Species and Cultivar Trials o vo vo VO VO h hp p p p p p p vo p p p p p p p p p p p p p p p p p p p p p b O ©©o p C Op p C Op p p p p p p o p p p p p p p p p p p p p Op p p p p p p p p C < VO VO vdv o vdvdvdvdvdvdvdvdvdvdvdvdvdvdvdvdv o vdvdvdvovdvdv o vdv o vdv o v o vdv o vdvdvdv d C/3 O OC Op p p p p p p p C Op o p p p p p p p p p p p C Op p p p p p p p p C ©o o p C vd vd vd vdvd vd i> vd vo vd vd vdvdvd vdv o V vd O Op OC Op p p p p p p p p p p p p p p p p p p p p t- p p p p p p p p C OC OC & p p pC vd vd of of or v o of vo vo v vo dvo of v o v o of v o ’ dvdvdvdvdv o dv d» dvdvd< V O dv dv dv v ov ov s Oo p p p P p p p p p p p o > p Oo C Oo o p p p p p p p o p o p o o r- p p o p P C o -H*— H< OO n C OvdO n Oh ON o N C r vdON of vdON vd(NC ON ON v r-’ O n ON dvd vd CM "d ON ON ON or ON ON o oON ON tu ON ON ON ON ON ON O v ON ON ON ON ON ON ON ON ON ON ON ON ON ON ON ON ON ON ON ON ON ON ON ON ON ON ON ON ON o > pp pC P p o p Op P p p P o p p p p OP p P l> p p r- p p Op p p o Po o p o 'C ’ vd© v o © O o ’ Ovdvdo Ovd00 o OO Oof V Ov o 1-HO Or-Hvovoor OC OO O _h OrJ, oo_h cooooo© vdo vdC oo00 vo roor- r- r- VO VO 00 o ro00 00 o or- ON O00 O00 o o00 r- O oON 00 ooO Oo C O oo00 ooO o 3 > p ©p ©p r- r- p p p p p o p p p p p o P p r- p p p p p p P o P p p p p p p p p o ' vdvoo ▼ — HvovdvdC o ovof-HC Ooovd00 o o Oo o C Oooo oo o ovdvdvdvd,-h vdvdc>o o oo©oovdvd_3 OvovooovoVO o t"* r- or vovovovoVO or or or vovoVO or vovo or- voVO ooVO r- VO vovoV o vol> o VO o CO 3 Q Op p Op p p P p p p p p p p p p p p p p p p p p Op p p p p p p p p p ©p p C O vdvdvdvdr>O vd vdvdvd oovdvdvdvdvd vdvdvd 00 «g o ©p p C Op p p p p p p p p p p p p p p p p p p p p p p p p p p p p p p p p p dvdvdvdvdvdvdvd vdvdvd vdvdvdvdvdvdvdvovdvdvdvdvdvdvovdvovdvdvdvovdvdvovd VO v Op p p p p p p p p p p p p p p p p p p p p p p p p Op p p p p p p p C £ p pp pC dvdid vdvdvdvovovovovdvovovovdvovovovovovovovovovdvdvdvdvd O vdvdvovdvdvdvdvdvdvd> Op p p p p p p r- p p p p p p p o p p p OP p p p p p p Op p p p p p C OC o p p ©C u 00 o o o oooo o 00 vd vdvd dvdvd vdvd vo vdoo» O co co Uh 3 > *3 CJ On ON vo .2 2 ^3" i * 3 Oh 1 H 3 r - oo i (N o e CO 03 r > 00 Q 1 £ o i vo a H 1 3 I—} ► —I C/5 U O h GO H 2 z o ON ^r vo 0^ < 00 CM CO 'd VO VO v o v o vo o oo 1 vo vo CO 1 3 o o o 2 £ £ o o CM #3 ’ l_ 0 4 G h GO vo vo vo vo r vo 00 vo oo Q W o 11 o o o ON o CO 1 vo ^ GO r - c o O h 03 3 0 - ------g eg N o ON vo vo f-H vo CO oo 1-H CM 1 C/3 Oh is no £, ^ vo vo N CM r vo CM 1 CO o3 cu < N oo vo ON vo r - o vo oo CO VO v o 1 vo ON H CO •—1 c u ^ vo vo oo 1 o £ o o o CM o 04 CM CO ^ r r - VO v o Species and Cultivar Trials T3 C 3 coOX) ,p p ON ON O n ON O n O s ON ON oo oo OO 00 00 p P p P P o p p p un d" p un id id id »d wd id id id id id un un un un un un un un un un un un un un un d- Id w > oo Ph ,__l O CO CO CO CO p p p p p p p p p p p p p p p p p p p p p p p vd wd wd id id id NO vd vd NO id un NO un NO NO un vd un un un NO vd d- un d- un 1 < >u o o T3 £ 2OX) Ih 2 2 9 CZ) >—✓ > o Visual quality o p p o p p p p p P p p O p p o p p p p p o p p p P p p NO id id NO id NO NO NO vd id id un vd NO NO NO un NO un un un NO un un un un un p CO CO o CO © © p p p p p p P P O p P p p p p p p p p p p id un id vd s -n cr o to o CD O *-> — °o V, g p p CO CO CO o p p p p p p p p P p p p p P p p P p p p p p id id NO id d id id d* d- NO d- un ■d- un cn cn d- cn d* un d- cn d* d- cn cn cn CN > ob -a OcX) g ’£3 o Poh cd fx r- p p p P p p p p p p P p p p p p o p p cn p p p r- CO CO CN d d" d* d ON ON d* oo d NO ■d- NO d- cn c> ON d ON d- i— 3 d ON d d- vd oo — 3 ON ON Os ON ON OO OO oo oo ON OO ON ON ON ON ON OO ON ON oo ON ON ON oo ON OO oo CN > oo 3 00 CO p CO CO CO p cd NO NO oo NO o r- OO OO r- OO > oo 00 CO CO CO CO p p cn P p p p p O cn p p O p p p o p P p O p p d; 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E. Christians and James R. Dickson This was the establishment year of data from the new tall fescue trial. This is a National Turfgrass Evaluation Program (NTEP) trial. It is being conducted at many locations around the U.S. The purpose of the trial is to study the regional adaptation of 129 tall fescue cultivars. Cultivars were evaluated for seedling vigor in October. The study is established in full sun. Three replications of the 3 x 5 ft (15 fit2) plots were established for each cultivar in the fall of 1996. The trial is maintained at a 2-inch mowing height, 3.5 lbs N/1000 fit2 will be applied during the growing season, and the area will be irrigated when needed to prevent drought. Preemergence herbicide was applied once in the spring. Seedling vigor was rated on a 9 to 1 scale: 9 = best vigor and 1 = worst vigor. Table 1. The 1997 quality ratings for the fine fescue regional cultivar trial. Mean seedling Cultivar Cultivar vigor 1 Renegade 8.0 30 JTTFA-96 2 Titan 2 8.0 31 PC-AO 8.0 32 SRX 8084 3 Safari 4 Genesis 7.7 33 Apache II 5 Falcon II 34 Marksman 7.7 6 Southern Choice 35 Regiment 7.7 7 TMI-RBR 7.7 36 ISI-TF9 8 Shenandoah 7.7 37 WRS2 9 MB 28 7.7 38 ATF-257 10 CU9501T 7.7 39 SSDE31 11 Kentucky - 31 w/endo 7.7 40 PST-R5AE 12 PSII-TF-9 7.7 41 Mustang II 13 Tarheel 42 BAR FA 6LV 7.7 14 AA-989 7.3 43 TA-7 15 Alamo E+ 44 TMI-FMN 7.3 16 Arid 7.3 45 DLF-1 17 PST-5RT 7.3 46 Pixie E+ 18 WVPB-1C 47 Duster 7.3 19 AA-A91 7.3 48 SS45DW 2 0 DP-7952 7.3 49 MB 216 21 SR 8210 7.3 50 ATF-196 2 2 Pennington-1901 7.3 51 TMI-AZ 23 PST-R5TK 7.3 52 PST-5E5 24 EC-101 7.3 53 Shortstop II 25 MB 212 54 OFI-931 7.3 26 ISI-TF11 7.3 55 PSII-TF-10 MB 210 27 7.3 56 PST-523 28 R5AU 57 Gazelle 7.3 7.3 58 JTTFC-96 29 CU9502T 13 Mean seedling vigor 7.3 7.3 7.3 7.3 7.3 7.3 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 Species and Cultivar Trials Cultivar 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 SRX 8500 Koos 96-14 MB 214 Bullet ZPS-5LZ MB 29 BAR Fa6 US1 MB 213 MB 26 WX3-275 Tomahawk-E BAR FA6 US6 F LTP-4026 E+ J-101 Tulsa Pick FA 15-92 Leprechaun OFI-96-31 Coyote Finelawn Petite BAR FA 6 D EA 41 WVPB-1D AV-1 ATF-182 RG-93 BAR Fa6 US2U Jaguar 3 ATF-253 Pick FA XK-95 JSC-1 TMI-TW Lion PST-5M5 J-98 Coronado Mean seedling vigor 7.0 7.0 7.0 6.7 6.7 6.7 6.7 6.7 6.7 6.7 6.7 6.7 6.7 6.7 6.7 6.7 6.7 6.7 6.7 6.5 6.3 6.3 6.3 6.3 6.3 6.3 6.3 6.3 6.3 6.3 6.3 6.3 6.3 6.3 6.3 6.3 Cultivar 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 14 OFI-96-32 MB 215 TMI-N91 ATF-188 DP 50-9011 PRO 8430 Empress Bonsai Pick FA 20-92 ATF-192 Pick FA 6-91 BAR Fa6 D USA OFI-FWY Pick GA-96 Cochise II MB 211 ATF-020 Pick FA B-93 AA-983 LTP-SD-TF AFT-022 ZPS-2PTF Pick FA N-93 OFI-951 Pick RT-95 BAR Fa6 US3 Crossfire II ATF-038 J-5 WVPB-1B PST-5TO J-3 Pick FA UT-93 ISI-TF10 Sunpro LSDq05 Mean seedling vigor 6.3 6.3 6.3 6.3 6.3 6.3 6.3 6.3 6.3 6.3 6.3 6.3 6.3 6 .0 6 .0 6 .0 6 .0 6 .0 6.0 6.0 6.0 6.0 6.0 6.0 6.0 6.0 6.0 5.7 5.7 5.7 5.7 5.7 5.7 5.7 5.7 Species and Cultivar Trials Regional Fine Fescue Cultivar Evaluation - Established 1993 Nick. E. Christians and James R. Dickson This was the third year of data from the new fine fescue trial. This is a National Turfgrass Evaluation Program (NTEP) trial. It is being conducted at many locations around the U.S. The purpose of the trial is to study the regional adaptation of 59 fine fescue cultivars. Cultivars were evaluated for quality each month of the growing season through October. The study is established in full sun. Three replications of the 3 x 5 ft (15 ft2) plots were established for each cultivar in September of 1993. The trial is maintained at a 2-inch mowing height, 3.5 lbs N/1000 fit2 were applied during the growing season, and the area was irrigated when needed to prevent drought. Preemergence herbicide was applied once in the spring. Visual quality was based on a 9 to 1 scale: 9 = best quality, 6 = lowest acceptable quality, and 1 = poorest quality. Data on spring greenup are also included. Table 1. The 1997 quality ratings for the fine fescue regional cultivar trial.___________ Cultivar 1 Rondo 2 Aruba 3 PST-4VB endo. 4 Shademaster II 5 Shadow II (PST-44D) 6 PST-4DT 7 PST-4ST 8 Jasper(E) 9 Common Creeping 10 K-2 (MB 65-93) 11 Tiffany 12 Flyer II (ZPS-4BN) 13 Victory (E) 14 Victory II (Pick 4-91W) 15 BAR FRR 4ZBD 16 BAR UR 204 17 Molinda 18 Banner III (MB 61-93) 19 CAS-FR13 20 Columbra (MB 64-93) 21 Medina 22 NJ F-93 23 Sandpiper (PRO 92/20) 24 Treazure (ZPS-MG) 25 MB 66-93 26 Seabreeze 27 SR 5100 28 Bridgeport 29 Brittany 30 ISI-FC-62 31 Jamestown II Species STC STC STC STC CF STC STC STC STC CF CF STC CF CF STC STC CF CF STC CF CF CF CF CF CF SLC CF CF CF CF CF Greenup 5.0 6.0 5.0 3.7 5.7 5.0 4.0 4.7 5.0 6.0 4.3 5.3 5.7 4.7 5.0 6.0 6.3 5.0 5.7 5.3 6.0 4.3 5.0 5.3 6.0 5.0 5.3 5.0 5.0 5.0 5.3 May 7.7 7.0 8.0 8.0 8.3 7.3 7.0 7.3 7.0 7.3 6.0 8.3 7.3 7.0 7.3 6.0 7.0 7.0 7.0 7.7 7.7 7.7 6.7 6.7 7.7 6.7 7.0 6.3 7.0 7.0 6.7 15 June 8.0 7.7 7.3 7.3 7.0 7.7 7.7 7.3 7.7 6.7 7.3 6.3 6.7 6.3 7.0 6.7 6.3 6.7 7.0 6.3 6.0 6.7 7.0 6.0 6.3 6.3 6.7 6.7 6.7 6.0 6.0 July 8.0 7.7 7.3 7.0 7.0 6.3 7.3 6.7 7.7 6.7 7.0 6.0 6.7 6.0 6.0 7.0 6.3 5.7 6.7 6.7 5.7 6.0 6.0 6.7 5.7 7.0 6.3 5.7 6.0 7.0 6.0 Quality Aug Sept Oct Mean 7.7 8.0 6.7 6.3 6.7 6.7 7.0 7.0 7.0 6.7 6.7 6.3 6.3 6.3 6.3 7.0 6.7 5.7 6.7 6.7 6.3 6.0 6.3 7.0 6.3 6.3 6.3 6.3 6.0 6.0 6.3 7.7 8.0 7.7 8.0 8.0 8.0 7.3 7.3 6.7 7.3 7.3 7.3 7.0 7.7 6.0 7.0 7.3 7.7 6.0 6.0 6.7 6.7 7.0 6.3 6.3 6.3 7.0 7.0 6.3 6.3 6.7 8.3 7.7 7.7 7.7 '7.3 8.0 7.3 7.7 6.0 7.0 7.0 6.7 6.7 7.7 7.3 6.7 6.3 7.0 6.0 6.3 7.0 6.3 6.7 7.0 6.7 6.3 5.7 6.7 6.7 6.3 7.0 7.9 7.7 7.4 7.4 7.4 7.3 7.3 7.2 7.0 6.9 6.9 6.8 6.8 6.8 6.7 6.7 6.7 6.6 6.6 6.6 6.6 6.6 6.6 6.6 6.5 6.5 6.5 6.4 6.4 6.4 6.4 Species and Cultivar Trials Cultivar 32 33 34 35 36 37 38 39 40 41 42 43 44 45 WX3-FFG6 Darwin ECO (MB 63-93) Osprey (PRO 92/24) WX3-FF54 Banner II Discovery MB 82-93 Shadow (E) Flyer TMI-3CE Jamestown Dawson Silverlawn (WVPBSTCR-101) Reliant II SR 3100 Ecostar Cascade Defiant (MB 81-93) Quatro (FO 143) Spartan Brigade Aurora W/Endo Nordic Pamela Vernon (MB 83-93) Scaldis 67135 Species STC CF CF HF CF CF HF HF CF STC CF CF SLC HF Greenup 5.3 4.3 5.3 3.7 5.0 5.7 4.3 4.3 5.7 4.7 5.0 5.7 5.0 4.7 May 6.3 6.7 6.7 6.7 7.7 7.7 7.0 6.0 8.0 5.7 6.0 7.0 4.3 7.3 June 7.3 6.7 6.0 7.0 6.0 5.7 7.0 6.0 5.7 5.3 6.0 6.0 6.0 6.3 HF 4.7 6.7 6.3 HF 4.3 6.0 6.7 HF 4.3 7.0 5.7 CF 6.0 5.3 6.0 HF 5.0 6.7 5.3 SF 6.7 4.3 5.3 HF 5.3 6.0 5.3 4.7 HF 6.0 5.7 HF 5.0 5.7 5.3 HF 5.3 6.3 5.0 HF 5.3 6.3 5.3 HF 4.3 6.7 5.0 HF 4.7 5.7 5.3 SF 8.7 4.7 4.7 — 1.7 2.1 1.7 L S D ( o.o5> Species: CF = Chewings Fescue HF = Hard Fescue SF = Sheep Fescue SLC = Slender Creeping Fescue STC = Strong Creeping Fescue Spring greenup (Greenup): 9 = dark green and 1 = light green. Quality based on a 9 to 1 scale: 9 = best quality, 6 = lowest acceptable 46 47 48 49 50 51 52 53 54 55 56 57 58 59 16 July 6.0 6.3 6.3 5.7 5.7 5.3 5.3 6.3 5.3 6.7 5.7 5.3 5.7 6.0 Quality Aug 6.3 6.7 6.3 6.0 5.7 6.3 6.0 6.7 5.7 5.7 6.0 5.7 5.7 4.7 Sept 6.7 5.7 6.3 6.7 6.7 6.0 6.0 6.0 6.7 6.3 6.0 5.7 5.3 4.3 Oct 6.0 5.7 6.3 6.0 6.3 6.3 6.0 6.0 6.0 6.3 6.0 5.3 6.0 4.3 Mean 6.4 6.3 6.3 6.3 6.3 6.2 6.2 6.2 6.2 6.0 5.9 5.8 5.5 5.5 4.7 5.0 4.3 5.0 5.0 4.7 4.3 4.7 4.3 4.7 4.3 4.3 3.7 3.7 1.4 5.0 5.3 4.3 5.3 4.3 4.3 4.3 4.3 4.0 4.0 4.7 4.0 3.7 3.7 1.3 4.7 4.3 4.7 4.0 4.3 4.3 5.3 4.0 4.0 4.0 3.7 4.0 4.0 3.3 1.6 5.3 5.0 5.0 4.7 5.0 5.0 4.7 4.0 4.7 4.3 4.0 3.7 4.0 3.3 1.6 5.4 5.4 5.2 5.1 5.1 5.1 5.0 4.8 4.7 4.7 4.7 4.6 4.4 3.9 0.9 quality, and 1 = poorest quality. Species and Cultivar Trials Perennial Ryegrass Study - Established 1994 James R. Dickson and Nick E. Christians This trial began in the fall of 1994 with the establishment of 96 cultivars of perennial ryegrass at the Iowa State University Horticulture Research Station. The study was established on an irrigated area that was maintained at a 2-inch mowing height and fertilized with 3 to 4 lb N/1000 ft2/yr. The area receives preemergence herbicide in the spring and was treated with a broadleaf herbicide in September of 1994. Cultivars were evaluated for turf quality each month of the growing season. Visual quality was based on a 9 to 1 scale: 9 = best quality, 6 = lowest acceptable quality, and 1 = poorest quality. The values listed under each month in Table 1 are the averages of ratings made on three replicated plots for the three studies. Yearly means of data from each month are listed in the last column. The cultivars are listed in descending order of average quality. Data on genetic color (Gcolor), leaf texture (Ltex), and greenup (gmup) ratings also are included. Table 1. The 1996 quality and other ratings for the national perennial ryegrass study established in 1994. Cultivar Gcolor Gmup Ltex May June July Aug Sept Oct Mean 1 J1706 6.7 5.3 4.3 5.7 7.3 8.0 7.3 7.3 7.7 7.2 2 Bar USA 94-11 7.3 6.0 4.7 5.7 7.0 7.7 7.3 7.3 7.3 7.1 3 Omega3 (ZPS-2DR-94) 7.0 6.0 3.7 5.7 6.7 7.7 7.0 7.7 7.3 7.0 4 Vivid 7.0 6.0 4.3 5.3 6.3 8.3 7.0 7.3 7.7 7.0 5 Line Drive (MB 47) 7.7 5.7 4.3 5.3 7.0 6.7 7.3 7.7 7.3 6.9 6 Excel (MB 1-5) 7.7 7.0 4.7 6.0 6.3 8.3 6.7 6.3 7.0 6.8 7 PST-2R3 7.0 5.3 4.3 5.3 6.7 7.7 7.3 7.0 7.0 6.8 8 RPBD 7.0 6.7 4.3 5.0 7.0 6.7 7.0 7.3 7.7 6.8 9 SR 4010 (SRX 4010) 6.3 6.0 4.0 5.7 6.3 7.3 6.7 7.3 7.3 6.8 TMI-EXFLP94 6.7 6.0 5.0 5.7 6.7 7.3 7.0 6.7 7.3 6.8 10 11 Accent 6.3 5.0 5.0 4.7 6.7 7.3 6.7 7.3 7.3 6.7 12 Express 7.0 6.7 4.0 6.0 7.0 7.0 5.7 7.0 7.3 6.7 13 ISI-R2 6.3 6.7 4.3 5.7 7.3 6.0 6.3 7.3 7.7 6.7 14 KOOS 93-6 6.7 5.3 4.3 5.3 6.7 7.0 6.3 7.3 7.7 6.7 15 LRF-94-MPRH 7.3 5.3 3.7 5.3 6.3 6.7 7.7 7.0 7.3 6.7 16 MB 45 7.7 5.7 3.7 4.7 7.0 8.0 7.3 6.3 6.7 6.7 17 MED5071 6.3 6.0 4.3 5.3 7.3 6.7 6.3 7.7 7.0 6.7 18 Nobility 7.3 5.0 4.7 5.3 6.7 7.7 6.3 7.0 7.3 6.7 19 SR 4400 (SRX 4400) 6.7 5.3 4.0 4.7 7.0 7.3 6.7 7.3 7.3 6.7 20 Wind Star (PST-28M) 6.7 5.7 4.3 5.3 6.7 7.3 6.7 7.3 7.0 6.7 21 WVPB 92-4 6.3 5.3 4.3 5.0 6.7 7.3 6.3 7.3 7.3 6.7 22 Dancer 7.3 4.0 4.7 5.0 6.7 7.0 7.0 6.7 7.0 6.6 23 Divine 7.0 6.0 3.7 5.0 7.0 8.0 6.0 6.3 7.0 6.6 24 Elf 6.0 6.3 4.3 5.0 7.0 7.3 7.0 6.3 6.7 6.6 25 Laredo 6.3 6.0 4.3 5.3 6.3 6.7 6.7 7.3 7.0 6.6 17 Species and Cultivar Trials Cultivar Gcolor Gmup Ltex May June July Aug Sept Oct Mean 26 Manhattan 3 6.3 6.3 4.3 5.0 6.0 7.0 6.7 7.3 7.3 6.6 27 Pennant II (MB 42) 8.0 4.7 4.0 4.7 6.7 7.3 6.7 7.3 7.0 6.6 28 PST-GH-94 7.7 4.7 3.7 4.7 6.7 7.3 6.7 6.7 7.3 6.6 29 ZPS-2NV 6.3 5.0 4.0 5.0 7.0 6.3 7.0 7.3 7.0 6.6 30 Advantage 7.7 4.7 4.3 5.0 7.0 6.3 6.3 7.0 7.3 6.5 31 Cutter 6.3 6.0 3.7 5.7 7.0 6.3 6.7 6.3 7.0 6.5 32 DLP 1305 6.7 5.3 3.7 5.3 6.7 6.3 6.7 7.0 7.0 6.5 33 MB 44 6.7 4.7 3.3 4.7 6.3 7.7 7.0 6.3 7.0 6.5 34 Panther (ZPS-PR1) 6.7 5.7 4.7 5.0 7.0 6.7 6.7 6.7 7.0 6.5 35 PS-D-9 6.7 4.7 4.3 5.0 6.7 6.7 6.7 6.7 7.3 6.5 36 Saturn II (ZPS-2ST) 7.0 6.3 4.3 5.3 7.0 6.7 6.3 7.0 6.7 6.5 37 Wizard (MB 41) 7.0 6.3 3.7 5.7 7.0 6.3 6.0 7.0 7.0 6.5 38 WVPB-93-KFK 6.0 5.7 4.3 5.0 6.7 6.3 6.7 7.0 7.3 6.5 39 Academy (PC-93-1) 6.3 6.0 5.0 5.3 6.7 7.0 6.0 6.7 7.0 6.4 40 Achiever 6.0 6.7 3.7 5.3 6.0 7.0 6.3 6.7 7.0 6.4 41 BAR ER 5813 6.7 5.0 3.7 4.7 6.7 6.7 6.3 7.0 7.0 6.4 42 ISI-MHB 7.0 5.0 3.7 4.7 7.0 6.7 6.3 7.0 6.7 6.4 43 MVF-4-1 7.0 5.7 4.0 5.0 6.0 7.0 6.0 7.0 7.7 6.4 44 PICK LP 102-92 7.7 5.7 4.0 4.7 7.0 7.3 6.7 6.3 6.7 6.4 45 PST-2DLM 7.7 5.7 3.7 4.7 7.0 6.3 6.7 7.0 6.7 6.4 46 SR 4200 6.3 5.7 4.7 5.3 6.3 6.3 6.3 7.0 7.0 6.4 47 APR 106 6.7 5.0 5.0 5.0 6.3 6.0 6.3 7.0 7.0 6.3 48 APR 124 6.7 5.7 4.7 5.7 6.3 6.3 6.3 6.3 7.0 6.3 49 Blazer III (PICK 928) 6.7 5.0 4.0 4.7 6.7 7.0 5.7 7.0 6.7 6.3 50 Calypso II 7.0 6.0 4.0 5.0 7.0 6.3 6.3 6.3 6.7 6.3 51 Edge 6.7 5.7 4.7 5.0 6.3 7.0 6.0 6.3 7.3 6.3 52 Majesty (MB 43) 7.0 5.0 4.3 4.7 7.0 6.7 6.0 6.7 7.0 6.3 53 PSI-E-1 6.3 5.7 4.0 4.7 6.3 7.0 6.7 6.3 7.0 6.3 54 PST-2CB 7.3 5.7 4.0 5.0 6.3 6.3 6.3 6.7 7.0 6.3 55 Roadrunner (PST-2ET) 6.7 6.3 4.3 4.7 6.3 7.0 6.7 6.0 7.0 6.3 56 WX3-93 7.0 5.0 4.3 4.7 7.0 7.0 6.3 6.3 6.3 6.3 57 Assure 6.3 6.0 4.3 5.0 6.3 6.7 6.0 6.3 6.7 6.2 58 CAS-LP23 7.3 5.3 4.0 5.0 6.0 6.7 6.0 6.7 6.7 6.2 59 Esquire 7.0 5.7 4.3 5.0 7.0 7.3 5.7 5.7 6.7 6.2 60 KOOS 93-3 6.3 5.3 4.3 5.3 6.3 6.0 6.0 6.7 7.0 6.2 61 Legacy II (Lesco-Twf) 7.3 5.3 5.0 5.3 6.3 6.7 6.0 6.3 6.7 6.2 62 Omni 6.3 5.3 4.0 4.3 6.3 7.0 5.7 7.0 6.7 6.2 63 Precision 6.3 4.7 4.3 5.0 6.7 6.3 6.3 6.7 6.3 6.2 5.3 4.7 4.3 6.0 6.3 64 Prizm 6.7 6.3 7.0 7.0 6.2 65 Quickstart 6.7 5.7 4.3 4.3 6.3 7.0 6.0 6.3 7.3 6.2 66 Riviera II 7.0 5.7 4.7 4.3 6.7 6.7 6.7 6.3 6.3 6.2 67 Stallion Select 7.0 5.7 4.0 5.3 6.0 6.7 6.0 6.7 6.7 6.5 18 Species and Cultivar Trials Cultivar 68 Williamsburg Gcolor 6.0 Gmup 6.0 Aug Ltex May June July 4.7 5.3 6.3 6.7 5.7 6.3 6.3 Oct Mean 6.7 6.7 6.2 6.7 6.7 6.2 Sept 69 WVPB-PR-C-2 7.0 6.3 4.7 5.3 5.7 70 Brightstar 7.3 5.7 4.7 4.7 6.3 6.7 6.3 6.3 6.3 6.1 71 Night Hawk 7.3 6.0 4.3 4.7 6.3 6.3 5.7 6.7 6.7 6.1 72 Passport (PST-2FF) 7.3 6.0 4.3 4.7 6.3 6.7 5.7 6.7 6.7 6.1 6.3 6.7 6.0 6.3 6.3 6.0 73 PICK PR 84-91 7.3 4.7 3.7 5.0 74 Saturn 6.7 4.7 4.7 4.7 6.7 6.0 5.7 6.7 6.7 6.1 75 PST-2FE 7.0 6.3 3.7 4.0 6.3 6.7 6.3 6.3 6.3 6.0 76 APR 066 6.3 5.0 4.3 4.3 6.0 6.0 6.0 6.7 6.7 5.9 6.0 6.7 5.9 APR 131 7.0 5.7 4.0 5.0 6.0 5.7 6.0 78 DSV NA 9402 6.0 4.3 4.3 4.3 5.7 5.7 6.0 7.0 7.0 5.9 79 Imagine 7.3 5.7 4.0 4.3 6.7 6.3 5.7 6.3 6.0 5.9 80 J -1703 6.3 5.7 4.3 4.0 6.3 6.3 5.7 6.3 6.7 5.9 81 Top Hat 7.3 6.3 3.7 4.0 6.7 6.3 6.3 5.7 6.3 5.9 5.0 3.3 3.7 6.3 6.0 6.0 6.3 6.7 5.8 77 82 Citation III (PST-2dgr) 6.7 83 Morning Star 7.0 4.3 4.3 4.7 6.0 5.3 5.3 6.3 7.0 5.8 84 Navajo 7.0 6.0 4.7 4.3 5.7 6.0 7.0 5.7 6.0 5.8 85 Pegasus 6.7 6.0 4.3 5.0 5.3 6.0 6.0 6.0 6.7 5.8 7.0 5.6 86 DSV NA 9401 6.0 3.7 4.7 4.3 6.0 5.0 4.3 6.7 87 Figaro 7.0 4.3 3.7 4.3 5.0 5.3 6.0 6.3 6.7 5.6 88 LRF-94-C8 7.7 5.3 3.0 4.0 5.7 5.7 5.7 6.3 6.0 5.6 89 Nine-O-Nine 7.7 4.7 4.3 4.0 4.7 6.3 6.0 6.0 6.0 5.5 90 Pennfine 7.0 5.3 2.3 4.7 6.3 5.3 4.7 5.7 6.3 5.5 4.0 5.3 6.0 5.3 5.7 6.3 5.4 91 LRF-94-B6 7.7 6.0 3.0 92 WX3-91 6.3 6.3 4.0 3.3 5.3 6.0 5.7 6.0 6.3 5.4 93 Brightstar II (PST-2M3) 7.7 5.3 2.7 3.0 5.7 5.7 5.7 5.7 6.0 5.3 94 MB 46 7.7 6.0 4.0 3.3 5.0 5.7 5.3 5.3 6.3 5.2 3.7 5.7 5.7 5.7 5.0 5.0 5.1 3.0 4.3 4.0 4.0 5.3 5.3 4.3 95 LRF-94-C7 7.7 6.3 3.0 96 Linn 5.7 3.7 2.0 1.4 1.7 1.2 1.7 2.2 1.0 1.9 2.3 2.1 2.0 LSD(o.os) Gcolor (Genetic color): 9 = dark green and 1 = light green. Ltex (Leaf textrue): 9 = fine and 1 = coarse. Gmup (Greenup): 9 = best and 1 = poorest greenup. Quality based on a 9 to 1 scale: 9 = best quality, 6 = lowest acceptable quality, and 1 = poorest quality. 19 Species and Cultivar Trials Shade Adaptation Studies Nick E. Christians, Barbara R. Bingaman, and Gary M. Peterson The first shade adaptation study was established in the fall of 1987 to evaluate the performance of 35 species and cultivars of grasses. The species include chewings fescue (C.F.), creeping red fescue (C.R.F.), hard fescue (H.F.), tall fescue (T.F.), Kentucky bluegrass (K.B.), and rough bluegrass (Poa trivialis). The area is located under the canopy of a mature stand of Siberian elm trees ( pumila) at the Iowa State University Horticulture Research Station north of Ames, Iowa. Grasses are mowed at a 2inch height and receive 2 lb N/1000 ft2/year. No weed control has been required on the area, but the grass was irrigated during extended drought periods. Monthly quality data are collected from May through October (Table 1). Visual quality was based on a 9 to 1 scale: 9 = best quality, 6 = lowest acceptable quality, and 1 = poorest quality. This trial has been observed through the extremes of the drought year 1988 and the very wet conditions of 1993. Turf quality among species varied greatly with moisture conditions. In dry weather, the fine fescues, especially the hard fescues, do well, whereas rough bluegrass quickly deteriorates. In extended wet periods, rough bluegrass does very well. Some of the tall fescues and chewings fescues also tend to perform better in wet conditions. A new shade trial was added in the fall of 1994 to evaluate the performance of cultivars of chewings fescue (C.F.), creeping red fescue (C.R.F.), hard fescue (H.F.), tall fescue (T.F.), Kentucky bluegrass (K.B.), and rough bluegrass {Poa trivialis), and Poa supina. The results from this trial appear in Table 2. Table 3 contains a summary of data from the last eight years for this project. Table 1. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 1996 quality1 ratings for turfgrass culitvars in the 1987 Shade Trial. Cultivar May June July Aug Sept Oct Mean Atlanta (C.F.) Victor (C.F.) Mary (C.F.) Banner (C.F.) Waldorf (C.F.) Wintergreen (C.F.) Jamestown (C.F.) Pennlawn (C.R.F.) Shadow (C.F.) Bar Fo 81-225 (H.F.) Agram (C.F.) St-2 (SR3000) (H.F.) Ensylkva (C.R.F.) Waldina (H.F.) Spartan (H.F.) Highlight (C.F.) Sabre {Poa trivialis) Reliant (H.F.) Biljart (H.F.) Koket (C.F.) Rebel (T.F.) Estica (C.R.F.) Rebell II (T.F.) 7.0 7.3 7.3 7.3 6.0 5.7 7.7 6.7 7.0 4.7 6.7 5.3 5.7 5.0 4.7 6.0 3.3 4.3 4.7 6.0 4.0 4.0 4.3 6.3 5.3 5.7 5.3 6.0 6.0 5.0 5.0 4.7 5.3 4.7 4.7 4.0 4.3 4.7 4.7 6.3 4.3 4.3 4.0 4.0 3.3 3.7 6.0 5.7 5.7 5.3 5.3 5.7 5.0 4.7 4.3 5.3 4.3 5.0 3.7 4.0 4.3 4.0 5.0 4.3 3.7 3.0 4.3 3.0 3.3 6.0 5.7 5.7 5.0 5.0 5.3 4.7 5.3 5.0 5.7 4.7 4.7 4.7 4.7 4.7 4.3 4.3 4.7 4.3 3.3 4.3 3.3 4.3 7.3 7.3 6.7 7.0 6.7 6.3 6.3 6.3 6.7 6.3 6.0 6.3 6.3 6.0 5.3 5.0 5.3 5.7 5.7 4.7 5.0 5.7 5.0 7.7 8.0 7.0 7.3 7.7 7.0 7.0 7.3 7.7 7.0 6.7 7.0 7.3 6.3 6.3 5.7 5.3 6.3 6.3 6.3 5.7 6.7 5.3 6.7 6.6 6.3 6.2 6.1 6.0 5.9 5.9 5.9 5.7 5.5 5.5 5.3 5.1 5.0 4.9 4.9 4.9 4.8 4.6 4.6 4.3 4.3 20 Species and Cultivar Trials Cultivar 24 25 26 27 28 29 30 31 32 33 34 35 Bonanza (T.F.) Falcon (T.F.) Scaldis (H.F.) Midnight (K.B.) Coventry (K.B.) Apache (T.F.) Arid (T.F.) Bristol (K.B.) Ram I (K.B.) Glade (K.B.) Chateau (K.B.) Nassau (K.B.) May June July Aug Sept Oct Mean 3.7 3.7 4.0 2.7 4.3 3.3 3.3 2.3 2.3 2.7 2.0 2.7 1.7 3.7 4.0 3.7 4.3 4.3 3.0 3.0 2.7 2.7 3.3 2.0 2.3 2.1 3.7 3.3 3.3 3.7 3.7 3.0 2.3 2.0 2.7 2.3 2.3 4.0 3.3 3.3 4.7 3.7 3.3 2.3 3.0 3.0 2.3 2.0 1.7 1.9 4.7 4.7 4.3 4.0 3.3 4.7 3.0 3.0 2.7 2.7 2.0 2.0 2.3 5.3 6.0 5.7 4.7 4.0 4.7 3.7 3.7 3.7 3.3 2.7 2.7 2.0 4.2 4.2 4.1 4.0 3.9 3.7 2.9 2.8 2.8 2.8 2.2 2.1 1.3 1.9 1.7 LSDo.os ‘Visual quality was assessed using a 9 to 1 scale: 9 = best quality, 6 = lowest acceptable quality, and 1 = poorest quality. Table 2. 1996 Visual quality1 data for turfgrass culitvars in the 1994 Shade Trial. Cultivar 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 Saber Cypress Polder SR 5100 Southport Bridgeport Banner Silvana Waldina Midnight Molinda Ascot Banner II Nordic Shadow Bonanza Spartan Shenandoah Victory Flyer Bonanza II Coventry Arid Glade Rebel II Bristol Buckingham Brigade Adobe Mirage Rebel Falcon II Bonsai Aztec Supranova May June July Aug Sept Oct Mean 7.0 6.7 6.7 6.3 5.0 5.3 5.7 4.3 4.3 4.7 4.3 3.0 4.7 4.0 4.0 4.7 3.3 3.7 4.7 4.0 3.0 5.0 3.3 4.3 3.3 3.3 2.3 3.7 2.3 3.0 2.3 2.7 1.7 2.0 1.0 2.2 6.3 6.7 6.3 5.3 4.0 4.0 4.0 4.0 4.0 4.7 3.0 4.3 3.7 3.0 3.7 3.3 3.0 3.0 2.7 3.3 3.7 3.3 3.3 3.0 2.3 3.7 3.0 2.0 2.3 2.0 2.3 2.3 1.7 2.0 1.7 1.7 5.7 5.3 5.3 4.7 4.3 4.0 3.3 4.0 4.3 4.0 3.7 3.7 3.7 3.0 3.0 3.7 3.7 3.3 2.7 3.3 3.3 2.7 3.7 2.7 3.0 2.7 3.0 2.3 2.3 2.0 2.3 2.3 2.0 2.3 1.0 2.0 5.3 5.0 5.7 5.0 3.7 3.3 4.3 4.0 3.7 4.0 3.0 3.7 3.7 4.0 3.0 3.0 3.3 3.7 2.7 2.7 3.0 3.0 2.7 3.0 3.3 2.3 3.0 2.3 2.3 2.0 2.3 1.7 2.0 1.7 1.7 2.0 6.7 7.0 6.7 6.3 5.7 5.3 5.3 5.0 4.0 3.7 4.7 4.3 4.0 4.3 4.0 3.7 4.0 4.0 3.7 3.7 4.0 3.0 3.7 3.0 3.7 3.3 2.3 2.7 2.7 2.3 2.0 2.0 2.0 2.7 1.7 2.3 7.3 6.7 6.7 6.7 6.0 6.0 5.7 6.3 5.7 4.3 6.3 5.3 4.7 5.3 5.7 5.0 5.3 5.0 5.0 4.7 4.7 3.3 3.7 4.0 4.3 3.7 3.7 4.3 3.0 3.0 2.7 3.0 3.0 2.0 2.3 2.1 6.4 6.2 6.2 5.7 4.8 4.7 4.7 4.6 4.3 4.2 4.2 4.1 4.1 3.9 3.9 3.9 3.8 3.8 3.6 3.6 3.6 3.4 3.4 3.3 3.3 3.2 2.9 2.9 2.5 2.4 2.3 2.3 2.1 2.1 1.6 1.7 LSDo os U T‘__ quality was assessed using a 9 to 1 scale: 9 = best quality, 6 = lowest acceptable quality, and 1 = poorest quality. ‘Visual 21 Species and Cultivar Trials Table 3. The average quality ratings for grasses in the Shade Trial: 1989 - 1996. Cultivar 1990 1991 1992 1994 1989 1993 1 Victor (C.F.) 2 ST-2 (SR 3000) (H.F.) 6.3 6.1 4.3 5.9 7.2 7.1 1995 1996 Ave.* 6.6 6.6 6.38 7.3 7.3 5.1 6.3 5.7 6.1 6.1 5.5 6.30 3 Mary (C.F.) 6.2 6.3 3.9 6.4 6.7 6.6 6.7 6.3 6.16 4 6.2 6.2 5.5 7.3 5.9 6.2 5.8 6.1 6.14 6.9 7.1 4.9 6.5 5.5 6.1 6.5 5.7 6.10 Waldorf (C.F.) 5 BAR FO 81-225 (H.F.) 6 Rebel (T.F.) 6.6 6.6 5.3 6.0 6.9 5.9 5.7 4.6 6.03 7 Jamestown (C.F.) 6.0 6.0 4.2 6.0 6.5 6.6 6.2 5.9 6.01 8 Estica (C.R.F.) 7.0 7.0 4.1 5.6 6.6 6.1 5.6 4.3 6.00 9 Bonanza (T.F.) 6.3 6.4 6.5 6.9 6.3 6.2 5.2 4.2 5.98 5.4 5.0 6.9 6.4 7.4 6.2 4.8 4.9 5.93 10 Sabre (Poa trivialis) 5.5 5.2 4.7 6.0 6.6 6.6 5.9 5.9 5.92 12 Falcon (T.F.) 6.4 6.3 5.3 6.0 6.5 6.3 5.2 4.2 5.87 13 Apache (T.F.) 6.6 6.8 6.0 6.0 6.3 5.4 5.3 3.7 5.87 14 Atlanta (C.F.) 5.7 5.7 4.9 6.1 5.8 5.7 5.5 6.7 5.86 11 Shadow (C.F.) 15 Waldina (H.F.) 6.8 6.8 4.1 5.5 5.5 5.8 5.8 5.1 5.83 16 Biljart (H.F.) 7.5 7.0 5.1 6.1 5.0 5.1 5.1 4.8 5.82 17 Pennlawn (C.R.F.) 5.8 5.6 4.7 6.2 6.3 5.5 5.5 5.9 5.80 18 Rebel II (T.F.) 6.6 6.8 5.3 5.6 6.1 6.2 5.1 4.3 5.78 19 Arid (T.F.) 6.3 6.3 6.0 7.1 6.7 5.6 4.7 2.9 5.71 20 Banner (C.F.) 5.6 6.0 4.5 5.0 6.0 5.6 5.3 6.2 5.68 21 Spartan (H.F.) 6.9 7.2 3.5 4.2 4.7 5.1 4.9 5.0 5.46 22 Wintergreen (C.F.) 5.6 5.5 4.6 5.9 5.0 5.0 5.0 6.0 5.41 23 Agram (C.F.) 5.6 5.3 3.9 5.9 5.4 5.3 5.1 5.5 5.41 24 Ensylva (C.R.F.) 5.4 5.2 4.0 5.1 5.9 5.4 4.4 5.3 5.31 25 Koket (C.F.) 5.4 4.9 4.2 5.2 5.2 5.7 4.6 4.6 5.12 26 Scaldis (H.F.) 6.5 5.8 3.7 5.2 4.6 4.4 4.8 4.1 5.07 27 Coventry (K.B.) 5.3 5.3 5.7 5.4 6.0 4.7 3.8 3.9 5.00 28 RAM I (K.B.) 6.1 5.2 5.0 5.0 5.9 4.3 3.3 2.8 4.87 29 Chateau (K.B.) 5.8 5.5 6.2 5.5 5.2 4.1 3.0 2.2 4.77 30 Highlight (C.F.) 4.9 4.8 3.5 4.6 5.0 4.8 4.7 4.9 4.70 31 Midnight (K.B.) 3.8 4.7 5.9 5.5 6.4 4.6 4.4 4.0 4.63 32 Glade (K.B.) 5.3 5.4 5.5 4.8 5.3 3.3 2.8 2.8 4.48 33 Reliant (H.F.) 3.7 3.9 3.1 3.5 4.2 4.9 4.8 4.9 4.26 34 Bristol (K.B.) 4.7 4.3 3.9 3.9 5.0 4.1 3.6 2.8 4.12 35 Nassau (K.B.) 4.1 3.7 3.4 3.8 4.3 3.3 2.4 2.1 3.49 Quality Based on a 9 to 1 scale: 9 = best quality, 6 = lowest acceptable quality, and 1 = poorest quality. *Average includes 1988 data (not listed). Compiled by Gary Peterson, ISU Extension Commercial Horticulture Field Specialist 22 Species and Cultivar Trials Fairway Height Bentgrass Study - Established 1993 Nick E. Christians and James R. Dickson This is the third year of data from the Fairway Height Bentgrass Cultivar trial established in the fall of 1993. Data collection began after the cultivars were fully established in July, 1994. The area is maintained at a 0.5-inch mowing height. This is a National Turfgrass Evaluation Program (NTEP) trial and is being conducted at several research stations in the U.S. It contains 21 of the newest seeded cultivars and a number of experimentáis. The cultivars are maintained with 4 lbs of N /1000 ft2/growing season. Fungicides are used as needed in a preventative program. Herbicides and insecticides are applied as needed. Table 1 contains monthly visual quality ratings for the 1996 season. Visual quality is based on a 9 to 1 scale: 9 = best quality, 6 = lowest acceptable quality, and 1 = poorest quality. Data on genetic color (Gcolor), leaf texture (Ltex), greenup, winter kill (Wkill), and (Gmup) ratings are also included. The highest rated cultivar in 1996 was 18th Green followed by Trueline and Lopez. The first thirteen cultivars are statistically the same. Table 1. The 1996 quality ratings for the fairway height bentgrass study. Cultivar 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 18th Green Trueline Lopez Penncross Pro/Cup Crenshaw Seaside OM-AT-90163 Providence Southshore ISI-AT-90162* Penneagle SR 7100 Cato Bar WS 42102 Penn G-2 (G-2) Seaside II (DF-1) Tendenz Bar AS 492 Penn G-6 (G-6) Exeter LSD(0.05) Gcolor 8.0 6.7 7.7 7.0 7.3 7.7 6.7 6.3 7.7 6.7 6.7 7.7 6.7 7.7 7.0 6.3 7.0 6.3 6.3 6.7 7.0 2.2 Ltex 6.7 6.3 7.0 5.7 6.7 7.0 6.0 7.0 6.7 6.7 7.0 7.3 7.3 6.7 8.0 6.3 7.0 7.0 7.3 6.7 6.7 NS Wkill 56.7 50.0 50.0 50.0 63.3 63.3 23.3 33.3 56.7 70.0 36.7 70.0 36.7 70.0 76.7 76.7 80.0 40.0 73.3 80.0 66.7 14.7 Gmup 6.0 5.3 5.3 5.3 5.3 6.0 7.7 7.3 5.0 4.7 6.7 4.3 7.7 5.0 4.7 5.3 4.3 7.0 4.7 4.3 6.7 0.9 May 6.7 6.3 6.0 5.3 5.0 4.0 6.7 6.7 5.3 3.3 6.0 4.0 5.7 3.0 3.0 3.3 2.7 6.0 3.7 2.7 4.0 1.6 June July 7.3 7.0 7.3 6.7 7.0 6.7 5.7 6.0 6.3 6.0 6.0 6.7 7.0 6.0 5.3 5.0 6.0 5.3 5.3 5.7 5.0 1.3 7.0 6.7 6.7 7.3 7.0 6.7 5.7 5.3 6.3 6.3 6.0 6.3 5.3 6.7 6.3 6.0 6.3 5.0 5.3 6.0 5.3 1.5 Quality Aug Sept 6.7 6.7 6.3 7.3 6.3 6.7 5.7 6.7 6.3 6.3 6.7 6.7 5.3 7.0 5.3 6.7 6.3 6.0 6.3 7.3 6.0 5.0 6.7 6.0 5.3 6.0 6.0 6.3 5.3 7.0 7.0 5.0 6.0 6.3 5.0 5.3 5.7 5.3 6.0 5.3 5.0 5.7 1.1 2.9 * Colonial Bentgrass Gcolor (Genetic color): 9 = dark green and 1 = light green. Ltex (Leaf texture): 9 = fine and 1 = coarse. Wkill (Winter kill): numbers represent % area killed. Gmup (Greenup): 9 = best and 1 = poorest greenup. Quality based on a 9 to 1 scale: 9 = best quality, 6 = lowest acceptable quality, and 1 = poorest quality. NS = means are not significantly different at the 0.05 level. 23 Oct 6.0 6.3 6.3 6.3 6.0 6.3 6.7 6.3 6.0 7.0 7.0 6.0 6.3 6.0 6.3 7.0 6.3 6.7 7.0 6.7 6.7 NS Mean 6.7 6.7 6.6 6.3 6.3 6.2 6.2 6.1 6.1 6.1 6.0 5.9 5.9 5.7 5.6 5.6 5.6 5.6 5.4 5.4 5.3 0.9 Species and Cultivar Trials Green Height Bentgrass Cultivar Trial (Native Soil) - Established 1993 Nick E. Christians and James R. Dickson This is the third year of data from the Green Height Bentgrass Cultivar trial established in the fall of 1993. The area was maintained at a 3/16-inch mowing height. This is a National Turfgrass Evaluation Program (NTEP) trial and is being conducted at several research stations in the U.S. It contains 28 seeded cultivars including a number of expérimentais. The cultivars are maintained with a fertilizer program of 1/4 lb N applied at 14-day intervals with a total of 4 lbs of N/1000 ft2/growing season. Fungicides are used as needed in a preventive program. Herbicides and insecticides are applied as needed. Pennlinks was the highest rated cultivar in 1996 (Table 1). The first 25 cultivars are statistically the same. Data on genetic color (Gcolor), leaf texture (Ltex), green up (Gmup), and winter kill (Wkill) ratings are also included in Table 1. Winter kill in the spring of 1996 was particularly bad. As can be seen from the data, some cultivars sustained much more damage than others. Table 1. The 1996 ratings for the green height bentgrass trial. Cultivar 1 Pennlinks 2 Providenc 3 Penn A-1(A-1) 4 18th Green 5 Regent 6 Southshore 7 Imperial (Syn 92-5) 8 Lofts L-93(l-93) 9 Century (Syn 92-1) 10 Msueb 11 Penncross 12 Cato 13 Crenshaw 14 DG-P 15 ISI-AP-89150 16 Penn G-2 (G-2) 17 Pro/Cup 18 SR 1020 19 Penn A-4(A-4) 20 Syn 92-2 21 Bar WS 42102 22 Mariner (Syn-1-88) 23 Trueline 24 Lopez 25 Penn G-6 (G-6) 26 Seaside 27 Bar AS 492 28 Tendenz L S D ( o.o5) Gcolor 7.3 7.7 7.7 7.7 6.3 7.3 7.3 7.0 6.3 6.0 7.0 7.3 7.3 6.7 7.0 7.0 6.7 7.0 7.0 6.7 7.0 6.0 6.3 6.0 6.0 6.0 6.3 5.7 2.1 Ltex 6.0 6.3 8.0 6.7 6.7 7.0 8.0 6.0 8.0 6.0 5.3 6.7 7.3 6.0 6.7 7.0 6.0 6.3 7.3 7.0 7.7 5.7 5.3 5.0 7.0 5.0 7.0 7.7 1.1 Wkill 50.0 70.0 63.3 63.3 46.7 56.7 63.3 53.3 53.3 46.7 43.3 76.7 73.3 53.3 50.0 76.7 46.7 73.3 70.0 70.0 76.7 46.7 60.0 63.3 76.7 60.0 70.0 63.3 22.2 Gmup 6.7 6.0 6.7 6.7 6.0 7.0 6.3 6.7 6.0 6.3 6.0 6.7 6.3 6.3 7.0 7.0 6.3 5.7 6.0 6.0 6.3 6.7 6.7 5.7 5.7 5.7 5.7 7.3 2.5 May 5.0 3.7 4.3 4.0 4.0 4.3 4.0 4.7 3.0 4.7 4.0 3.0 3.0 4.0 4.0 3.0 3.7 3.7 3.0 3.3 2.7 4.3 3.7 3.3 2.3 4.3 2.7 4.0 2.0 June 6.7 6.7 6.0 6.7 6.3 5.7 5.3 5.7 6.0 6.0 6.3 5.0 5.3 6.3 5.3 4.7 6.0 5.3 5.3 5.3 5.0 5.7 5.3 5.0 5.0 5.3 5.0 4.7 1.0 July 6.3 7.0 6.7 6.7 6.3 6.0 6.0 7.0 5.7 6.0 6.3 6.3 6.3 6.0 6.0 6.3 6.0 6.0 6.3 5.3 6.0 5.0 5.7 5.0 5.7 5.0 4.7 4.0 1.1 Quality Aug 6.0 6.0 6.7 6.0 5.7 6.3 6.0 6.3 6.7 5.3 5.3 6.0 6.3 5.0 5.3 5.7 5.7 5.7 6.0 6.0 5.7 5.7 5.3 5.7 6.3 4.7 4.7 4.3 1.0 Sept 6.3 6.7 6.3 6.0 6.3 7.0 6.3 5.7 6.3 6.0 6.0 6.7 6.0 6.0 6.0 7.0 6.3 6.3 6.0 6.0 6.7 6.0 6.7 6.3 6.3 5.3 6.3 5.0 2.6 Oct 6.0 6.3 6.0 6.0 7.0 6.3 7.3 5.7 6.7 6.3 6.0 6.3 6.3 6.3 6.7 7.0 6.0 6.7 6.3 7.0 6.7 5.7 6.0 6.3 5.7 5.3 6.3 5.0 3.0 Gcolor (Genetic color): 9 = dark green and 1 = light green.. Ltex (Leaf texture): 9 = fine and 1 = coarse. Wkill (Winter kill): numbers represent % area killed. Grnup(Green up): 9 = best and 1 = poorest greenup. Quality based on a 9 to 1 scale: 9 = best quality, 6 = lowest acceptable quality, and 1 = poorest quality. 24 Mean 6.1 6.1 6.0 5.9 5.9 5.9 5.8 5.8 5.7 5.7 5.7 5.6 5.6 5.6 5.6 5.6 5.6 5.6 5.5 5.5 5.4 5.4 5.4 5.3 5.2 5.0 4.9 4.5 0.9 Herbicide and Growth Regulator Studies Pre- and Postemergence Annual Weed Control Study - 1996 Barbara R. Bingaman, Nick E. Christians, and David S. Gardner Herbicides from AgrEvo, DowElanco, Gowan, Rohm and Haas Company, and Sandoz were screened for efficacy as preemergence, early post-, and postemergence products for annual weed control in turfgrass. The study was conducted at the Iowa State University Horticulture Station north of Ames, Iowa. The experimental plot was an area of ‘Nassau’ Kentucky bluegrass established in 1994. The soil was a Nicollet (fine-loamy, mixed, mesic Aquic Hapludoll) with 4.5% organic matter, a pH of 6.2, 30 ppm P, and 133 ppm K. The experiment was arranged in a randomized complete block design. Individual plots were 5 x 5 fit with three replications and no barrier rows between replications. The assignment of treatments to plots was randomized. There were a total of 46 treatments including two untreated control plots per replication (Table 1). Three experimental formulations and Pendimethalin, Team and Team/Gallery in combination with fertilizers were screened for DowElanco. NAF 191 was applied in split applications at 1.0 lb a.i./A, NAF 192 in a single application and split applications at 1.5 lb a.i./A, and NAF 193 in single applications at 2.0 lb a.i./A. Pendimethalin 0.86GR + fertilizer and Team 0.87GR + fertilizer were applied in split applications at 1.0 and 1.5 lb a.i./A. and in single applications at 1.5 and 2.0 lb a.i./A. Team/Gallery (Spring Valley) 1.09GR + fertilizer was applied in split applications at 2.04 lb a.i./A and in single applications at 2.720 lb a.i./A. The initial treatments were made preemergently before crabgrass germination and the sequential applications were made when the crabgrass was in the 1-3 tiller growth stage. Betasan and Tupersan from the Gowan Company were applied as preemergence herbicides. Betasan 4LF was applied at 2 gal product/A and Tupersan 50WP at 20 lb product/A. The Rohm and Haas products were applied in split applications of herbicide + fertilizer combinations. Each plot received the same amount of nitrogen when initial and sequential applications were made. Methylene urea fertilizer (39-0-0) was the fertilizer component of all formulations and also was used as the fertilizer ‘blank’ used to equalize the amount of applied N. Dimension 1EC was applied in single applications at 0.25 and 0.38 lb a.i./A and in split applications at 0.125 and 0.250 lb a.i./A. Three Dimension + fertilizer formulations (AD 442, AD 444, & AD 445) that contain different amounts of Dithiopyr and Dimension 1EC were used. AD 442 was applied in split applications at 0.060 lb a.i./A, AD 444 at 0.125 lb a.i./A in single and split applications, and AD 445 at 0.250 lb a.i./A in a single application. Barricade 65WG (Prodiamine) at 0.650 lb a.i./A, Pendimethalin 60WDG at 1.50 lb a.i./A in single applications, and a fertilized control were included for comparisons. Sequential applications were made 51 days after the initial application. Barricade 65WG from Sandoz was applied as a preemergence herbicide at 0.32, 0.48, 0.65 and 0.50 lb a.i./A. The 0.50 lb treated plots received a sequential treatment 60 days after the initial treatment at a lower rate (0.25 lb a.i./A). Acclaim Extra 68.5EW, Acclaim 120EC, and Preclaim 370.6EC were applied as early postemergence products at 0.060, 0.120, and 2.060 lb a.i./A, respectively, when the crabgrass was in the 1-3 leaf stage. These materials from AgrEvo also were applied postemergently at 0.090, 0.180, 3.090 lb a.i./A, respectively, when the crabgrass was tillering. Dimension 1EC was applied at 0.250 lb a.i./A as a preemergence product and in split applications at 0.125 lb a.i/A and at 0.250 lb a.i./A in a single postemergence application. Dimension 1EC also was applied postemergently at 0.25 lb a.i./A with Trimec Plus at 3 fl oz product/1000 ft2 and with 25 Herbicide and Growth Regulator Studies Preclaim at 3.09 lb a.i./A. Preclaim and Trimec Plus were applied alone at these same rates when the crabgrass was tillering. Liquid formulations were applied using a carbon dioxide backpack sprayer equipped with #8006 nozzles at 25-30 psi. The granular materials were applied using ‘shaker dispensers’. Preemergence treatments (treatments 1-32 and 39-40) were made on May 3 before crabgrass germination (Table 1). A pre-treatment survey of the plot confirmed that turf quality was uniform. The materials were ‘watered in’ with the irrigation system. On June 12, crabgrass plants were detected in the untreated control plots. The sequential application of granular treatments 22-32 was made on June 25 (51 days after initial application). The liquid formulations for treatments 22-32 and the early postemergence products (treatments 33-35) were applied on June 26 when the crabgrass was in the 1-3 leaf stage with no tillering. The sequential application of treatment 4 was made 60 days after the initial application on July 3. Postemergent applications (treatments 6, 8, 10, 12, 14, 15, 18, 36-38, and 40-45) were made on July 15 when the crabgrass was beginning to tiller. The turf was examined for visual quality throughout the study. Data were taken May 9, May 22, June 13, June 26, July 3, July 22, and August 13. Turf quality was assessed using a 9 to 1 scale: 9 = best quality, 6 = lowest acceptable quality, and 1 = poorest quality (Table 2). Kentucky bluegrass phytotoxicity was evaluated following herbicide applications using a 9 to 1 scale: 9 = no damage, 5 = uniform tip burning, 3 = severe burning & discoloration, and 1 = dead turf. Phytotoxicity data were taken July 10 following application of the early postemergence materials (Table 3). Crabgrass control was measured by counting the number of crabgrass plants in each plot on August 13 (Table 4). Crabgrass reductions were calculated by comparing crabgrass counts among the treated plots as compared with the untreated controls (treatments 1 and 46). All data were analyzed using the Statistical Analysis System (SAS) version 6.09 and the Analysis of Variance (ANOVA) procedure. Fisher’s Least Significant Difference (LSD) test was used to compare means among the treatments. Turf quality was equal in all treated and untreated plots in May and the first significant differences were detected on July 3 after the sequential applications for treatments 22-32 (Table 2). In these plots quality was significantly better than in the other treated and the untreated turf. By July 22, the quality improved in some plots receiving postemergence applications of herbicide + fertilizer formulations (treatments 6, 8, 15, and 18). Mean turf quality was above the lowest acceptable rating (a ‘6’) for all treatments including the untreated controls (Table 2). The best mean turf quality was achieved in Kentucky bluegrass treated with Pendimethalin 60WDG + fertilizer (treatment 23), Dimension 1EC + fertilizer (treatments 26 and 27), and the ‘AD’ experimental Dimension + fertilizer formulations (treatments 28-31). The only bluegrass phytotoxicity was detected July 10 in plots treated with the early postemergence herbicides on June 26 (treatments 33, 34, and 35). The bluegrass had severe tip burning and was discolored (Table 3). By July 22, the turf had recovered somewhat and was given either the lowest acceptable quality rating or lower (5’s and 6’s). The temperatures during this period were quite high and there was only minimal rainfall. These factors probably contributed to the impact of the herbicides on the bluegrass. Turf quality in these plots did not improve by August 13. Most herbicides significantly reduced the number of crabgrass plants when compared with the untreated controls and eighteen of the products provided > 90% reductions (Table 3). Pre- and postemergence applications of some herbicides resulted in better crabgrass control than single applications (treatments 7 and 15). 26 Herbicide and Growth Regulator Studies Table 1. Materials, rates and timing of application for materials used in the 1996 Preemergence & Postemergence _________Annual Grass Control Study. Amount of Rate Rate Amount of fertilizer Timing of Materials lb a.i./A. fertilizer lb a.i/A (initial) applications lb/1000 ft2 lb/1000 fi2 (sequential) (initial) (sequential) 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33. 34. 35. 36. 37. 38. 39. 40. 41. 42. 43. 44. 45. 46. Untreated control Barricade 65WG Barricade 65WG Barricade 65WG Barricade 65WG NAF-191 0.57GR + fert NAF-192 0.86GR + fert NAF-192 0.86GR + fert NAF-193 1.15GR + fert Pendimethalin 0.86GR + fert Pendimethalin 0.86GR + fert Pendimethalin 0.86GR + fert Pendimethalin 0.86GR + fert Team 0.87GR + fertilizer Team 0.87GR + fertilizer Team 0.87GR + fertilizer Team 0.87GR + fertilizer Team 1.09GR & Gallery + fert Team 1.09GR & Gallery + fert Tupersan 50WP Betasan4LF Barricade 65WG Pendimethalin 60WDG Dimension 1EC(& fertilizer) Dimension 1EC(& fertilizer) Dimension 1EC(& fertilizer) Dimension 1EC(& fertilizer) AD444 Dimension 0.072FG + fert AD445 Dimension 0.164FG + fert AD442 Dimension 0.035FG + fert AD444 Dimension 0.072FG + fert Fertilized control Acclaim Extra 68.5EW Acclaim 120EC Preclaim 370.6EC Acclaim Extra 68.5Ew Acclaim 120EC Preclaim 370.6EC Dimension 1EC Dimension 1EC Dimension 1EC Dimension 1EC + Trimec Plus Trimec Plus Dimension 1EC + Preclaim Preclaim Untreated control NA 0.320 0.480 0.500 0.650 1.000 1.500 1.500 2.000 1.000 1.500 1.500 2.000 1.000 1.500 1.500 2.000 2.040 2.720 20.0 lb/A 2.0 gal/A 0.650 1.500 0.250 0.380 0.125 0.250 0.125 0.250 0.060 0.125 NA 0.060 0.120 2.060 0.090 0.180 3.090 0.250 0.125 0.250 0.250 + 3 fl oz 3 fl oz 0.250 + 3.090 3.090 NA none none none none none NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA 4.0 4.0 4.0 4.0 4.0 4.0 4.0 3.5 4.0 4.0 4.0 none none none none none none none none none NA NA NA 0.250 NA 1.000 NA 1.500 NA 1.000 NA 1.500 NA 1.000 1.500 NA NA 2.040 NA NA NA none none none none 0.125 0.250 none none 0.060 0.125 NA NA NA NA NA NA NA NA NA NA none none none none none NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA 4.0 4.0 4.0 4.0 4.0 4.0 4.0 3.5 4.0 4.0 4.0 none none none none none none none none none NA PRE PRE PRE & POST PRE PRE & POST PRE PRE & POST PRE PRE & POST PRE PRE & POST PRE PRE & POST PRE & POST PRE PRE PRE & POST PRE PRE PRE PRE & POST PRE & POST PRE & POST PRE & POST PRE & POST PRE & POST PRE & POST PRE & POST PRE & POST PRE & POST NA EARLY POST EARLY POST EARLY POST POST POST POST PRE PRE & POST POST none none none NA NA NA none none none POST POST POST none none NA NA none none POST NA Treatments 1-32 and 39-40 were applied on May 3, trts 22-32 sequential on June 25, trt 4 sequential on July 3, and trts postemergence on 6, 8, 10, 12, 14, 15, 18, 36-38, and 40-45 on July 16. 27 Herbicide and Growth Regulator Studies Table 2. Visual quality1of Kentucky bluegrass treated with various herbicide formulations in the 1996 Preemergence ________ & Postemergence Annual Grass Study._________________________________________________________ 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33. 34. 35. 36. 37. 38. 39. 40. 41. 42. 43. 44. 45. 46. Materials May 9 May 22 June 13 June 26 July 3 July 22 August 13 Mean quality Untreated control Barricade 65WG Barricade 65WG Barricade 65WG Barricade 65WG NAF-191 0.57GR + fert NAF-192 0.86GR + fert NAF-192 0.86GR + fert NAF-193 1.15GR + fert Pendimethalin 0.86GR + fert Pendimethalin 0.86GR + fert Pendimethalin 0.86GR + fert Pendimethalin 0.86GR + fert Team 0.87GR + fert Team 0.87GR + fert Team 0.87GR + fert Team 0.87GR + fert Team 1.09GR & Gallery + fert Team 1.09GR & Gallety + fert Tupersan 50WP Betasan 4LF Barricade 65WG (& fert) Pendimethalin 60WDG (& fert) Dimension 1EC (& fert) Dimension 1EC (& fert) Dimension 1EC (& fert) Dimension 1EC (& fert) AD444 0.072FG + fert AD445 0.164FG + fert AD442 0.035FG + fert AD444 0.072FG + fert Fertilized control Acclaim Extra 68.5EW Acclaim 120EC Preclaim 370.6EC Acclaim Extra 68.5EW Acclaim 120EC Preclaim 370.6EC Dimension 1EC Dimension 1EC Dimension 1EC Dimension 1EC + Trimec Plus Trimec Plus Dimension 1EC + Preclaim Preclaim Untreated control 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 8 8 8 8 8 9 9 9 8 8 9 8 9 8 9 8 8 8 8 8 8 9 9 9 9 9 9 9 9 9 9 9 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 9 9 9 9 9 9 9 9 9 9 9 6 6 6 7 7 7 7 7 6 7 7 7 7 7 6 6 7 7 7 8 6 8 7 7 6 6 7 7 8 6 7 8 6 6 7 8 8 7 8 9 9 9 9 9 9 8 5 6 6 6 5 6 7 5 6 5 7 6 6 6 6 5 6 6 7 7 6 7 6 6 6 7 6 6 7 6 6 6 6 6 6 8 8 7 7 7 7 7 8 8 8 7 5 6 5 6 5 6 6 5 5 6 6 5 6 6 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 9 8 8 9 9 9 9 9 9 8 7 7 7 7 7 7 8 7 7 7 8 7 8 8 NS NS 1 NS 1 1 1 0.3 L SD oos 1 Visual quality was assessed using a 9 to 1 scale: 9 = best quality, 6 = lowest acceptable quality, and 1 = poorest quality. NS = means are not significantly different at the 0.05 level. Treatments 1-32 and 39-40 were applied on May 3, trts 22-32 sequential on June 25, trt 4 sequential on July 3, and trts postemergence on 6, 8, 10, 12, 14, 15, 18, 36-38, and 40-45 on July 16. 28 Herbicide and Growth Regulator Studies Table 3. Kentucky bluegrass phytotoxicity1 in the 1996 Preemergence & Postemergence Annual Grass Study. Materials 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33. 34. 35. 36. 37. 38. 39. 40. 41. 42. 43. 44. 45. 46. Untreated control Barricade 65WG Barricade 65 WG Barricade 65 WG Barricade 65 WG NAF-191 0.57GR + fertilizer NAF-192 0.86GR + fertilizer NAF-192 0.86GR +fertilizer N A F-193 1.15GR + fertilizer Pendimethalin 0.86GR + fertilizer Pendimethalin 0.86GR + fertilizer Pendimethalin 0.86GR + fertilizer Pendimethalin 0.86GR + fertilizer Team 0.87GR + fertilizer Team 0.87GR + fertilizer Team 0.87GR + fertilizer Team 0.87GR + fertilizer Team 1.09GR & Gallery + fertilizer Team 1.09GR & Gallery + fertilizer Tupersan 50WP Betasan 4LF Barricade 65WG (& fertilizer) Pendimethalin 60WDG (& fertilizer) Dimension 1EC (& fertilizer) Dimension 1EC (& fertilizer) Dimension 1EC (& fertilizer) Dimension 1EC (& fertilizer) AD444 0.072FG + fertilizer AD445 0.164FG + fertilizer AD442 0.035FG + fertilizer AD444 0.072FG + fertilizer F ertilized control Acclaim Extra 68.5EW Acclaim 120EC Preclaim 370.6EC Acclaim Extra 68.5EW Acclaim 120EC Preclaim 370.6EC Dimension 1EC Dimension 1EC Dimension 1EC Dimension 1EC + Trimec Plus Trimec Plus Dimension 1EC + Preclaim Preclaim Untreated control Rate (lb a.i./A) initial / sequential Timing of application NA 0.320 / NA 0.480 / NA 0.500 / 0.250 0.650 / NA 1.000 / 1.000 1.500/N A 1.500 / 1.500 2.000 / NA 1.000 / 1.000 1.500/N A 1.500 / 1.500 2.000 / NA 1.000 / 1.000 1.500 / 1.500 1.500/N A 2.000 / NA 2.040 / 2.040 2.720 / NA 20.0 lb/A / NA 2.0 gal/A / NA 0.650 & fert 1.500 & fert 0.250 & fert 0.380 & fert 0.125/0.125 0.250 / 0.250 0.125/fert 0.250 / fert 0.060 / 0.060 0.125 / 0.125 fert / fert 0.060 / NA 0.120/N A 2.060 / NA 0.090 / NA 0.180/N A 3.090 /N A 0.250 / NA 0.125 / 0.125 0.250/ NA 0.250 + 3 flo z/N A 3 flo z /N A 0.250 + 3.090/ NA 3.090 / NA NA NA PRE PRE PRE & POST PRE PRE & POST PRE PRE & POST PRE PRE & POST PRE PRE & POST PRE PRE & POST PRE & POST PRE PRE PRE & POST PRE PRE PRE PRE & POST PRE & POST PRE & POST PRE & POST PRE & POST PRE & POST PRE & POST PRE & POST PRE & POST PRE & POST PRE & POST EARLY POST EARLY POST EARLY POST POST POST POST PRE PRE & POST POST POST POST POST POST NA Phytotoxicity on July 10 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 3 3 3 9 9 9 9 9 9 9 9 9 9 9 NS2 LSD 0.05 1 Kentucky bluegrass phytotoxicity was determined following herbicide applications using a 9 to 1 scale: 9 = no damage, 5 = tip burning, 3 = severe burning & discoloration, and 1 = dead turf. Treatments 1-32 and 39-40 were applied on May 3, trts 22-32 sequential on June 25, trt 4 sequential on July 3, and trts postemergence on 6, 8, 10, 12, 14, 15, 18, 36-38, and 40-45 on July 16. ‘NS = LSD test is not valid for these data because there is no error among the replications. 29 Herbicide and Growth Regulator Studies Table 4. Number of crabgrass plants and percentage reductions1in crabgrass numbers in Kentucky bluegrass in the _________1996 Preemergence & Postemergence Annual Grass Study on August 13.___________________________ Number of Percent reduction Rate (lb a.i./A) Timing of crabgrass initial / in crabgrass plants Materials application plants per plot per plot1 sequential 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33. 34. 35. 36. 37. 38. 39. 40. 41. 42. 43. 44. 45. 46. NA Untreated control 0.320 / NA Barricade 65WG 0.480 / NA Barricade 65WG 0.500 / 0.250 Barricade 65WG 0.650/N A Barricade 65WG 1.000/ 1.000 NAF-191 0.57GR + fert 1.500/N A NAF-192 0.86GR + fert 1.500 / 1.500 NAF-192 0.86GR + fert 2.000 / NA NAF-193 1.15GR + fert Pendimethalin 0.86GR + fert 1.000 / 1.000 1.500/N A Pendimethalin 0.86GR + fert 1.500 / 1.500 Pendimethalin 0.86GR + fert 2.000 / NA Pendimethalin 0.86GR + fert Team 0.87GR + fert 1.000/ 1.000 1.500 / 1.500 Team 0.87GR + fert Team 0.87GR + fert 1.500/N A Team 0.87GR + fert 2.000 / NA Team 1.09GR & Gallery + fert 2.040 / 2.040 Team 1.09GR & Gallery + fert 2.720 / NA Tupersan 50WP 20.0 lb/A / NA Betasan 4LF 2.0 gal/A / NA Barricade 65WG (& fert) 0.650 & fert Pendimethalin 60WDG (& fert) 1.500 & fert Dimension 1EC (& fert) 0.250 & fert Dimension 1EC (& fert) 0.380 & fert Dimension 1EC (& fert) 0.125/0.125 Dimension 1EC (& fert) 0.250 / 0.250 AD444 0.072FG + fert 0.125/fert AD445 0.164FG + fert 0.250 /fert AD442 0.035FG + fert 0.060 / 0.060 AD444 0.072FG + fert 0.125/0.125 Fertilized control fert / fert Acclaim Extra 68.5EW 0.060 / NA Acclaim 120EC 0.120 / NA Preclaim 370.6EC 2.060 / NA Acclaim Extra 68.5EW 0.090 / NA Acclaim 120EC 0.180/N A Preclaim 370.6EC 3.090 / NA Dimension 1EC 0.250 / NA Dimension 1EC 0.125/0.125 Dimension 1EC 0.250 / NA Dimension 1EC + Trimec Plus 0.250+3 fl oz/NA Trimec Plus 3 floz/NA Dimension 1EC + Preclaim 0.250+3.090/NA Preclaim 3.090 / NA Untreated control NA LSD 0 0 5 NA PRE PRE PRE & POST PRE PRE & POST PRE PRE & POST PRE PRE & POST PRE PRE & POST PRE PRE & POST PRE & POST PRE PRE PRE & POST PRE PRE PRE PRE & POST PRE & POST PRE & POST PRE & POST PRE & POST PRE & POST PRE & POST PRE & POST PRE & POST PRE & POST PRE & POST EARLY POST EARLY POST EARLY POST POST POST POST PRE PRE & POST POST POST POST POST POST NA 83 6 6 0 2 66 92 24 15 33 37 67 32 39 22 70 16 36 45 110 5 1 31 26 3 3 0 18 5 1 1 58 33 43 1 8 5 2 29 94 40 0 85 1 44 128 0 94 95 100 98 38 13 77 86 69 65 37 70 64 80 34 85 66 58 0 96 99 71 75 97 97 100 83 96 99 99 45 69 59 99 92 95 98 72 11 62 100 19 99 58 0 46 43 1 Percent reduction in crabgrass counts were calculated as the mean number of crabgrass plants per plot compared with the mean number in the untreated controls (treatments 1 and 46). Treatments 1-32 and 39-40 were applied on May 3, trts 22-32 sequential on June 25, trt 4 sequential on July 3, and trts postemergence on 6, 8, 10, 12, 14, 15, 18, 36-38, and 40-45 on July 16. 30 Herbicide and Growth Regulator Studies Postemergence Annual Weed Control Study - 1996 Barbara R. Bingaman, Nick E. Christians, and David S. Gardner Herbicides from AgrEvo and Rohm and Haas Company were screened for efficacy as early post- and postemergence annual weed control products in turfgrass. This study was conducted at the Iowa State University Horticulture Research Station north of Ames, Iowa. The experimental plot was an area of ‘common’ Kentucky bluegrass. The soil was a Nicollet (fine-loamy, mixed, mesic Aquic Hapludoll) with 2.5% organic matter, a pH of 6.9, 7 ppm P, and 87 ppm K. Supplemental irrigation was used to keep the turf in good growing condition. The experiment was arranged in a randomized complete block design. Individual plots were 5 x 5 ft with three replications and 12 treatments. The assignment of treatments to plots was randomized. There were 11 herbicide treatments and an untreated control. Acclaim Extra 68.5EW, Acclaim 120EC, and Preclaim 370.6EC were applied as early postemergence products at 0.06, 0.12, and 2.06 lb a.i./A, respectively, and as postemergence products at 0.09, 0.18, and 3.09 lb a.i./A, respectively. Dimension 1EC was applied as a postemergence herbicide alone at 0.25 lb a.i./A and at this same rate in combination with Trimec Plus at 3 fl oz/1000 ft2 and Preclaim at 3.09 lb a.i./A. Trimec Plus and Preclaim also were applied alone at these same rates (Table 1). A pre-treatment survey of the experimental plot indicated that there was a large crabgrass population. The Kentucky bluegrass was uniform in quality throughout the plot. Early post- applications were made June 4. The crabgrass was in the 1-3 leaf stage and there was no evidence of tillering. The postemergence treatments were made July 12 when the crabgrass was in the 1-2 tiller growth stage. The plot was periodically examined for turf quality and phytotoxicity. Turf quality was assessed using a 9 to 1 scale: 9 = best quality, 6 = lowest acceptable quality, and 1 = poorest quality. Visual quality data were taken June 7, June 25, July 3, July 15, July 23, July 30, and August 8 (Table 1). The plot was checked for phytotoxicity following the early post- and postemergence applications. Effectiveness of the herbicides was measured by estimating the percentage of crabgrass cover in each plot on July 23, July 30, and August 8 (Table 2). Percentage reductions in crabgrass cover were calculated by comparing crabgrass counts from treated turf with those from the untreated controls. In addition, broadleaf weed populations were examined even though the distribution was sporadic. The number of spurge and oxalis plants per plot was counted on August 8 (Table 3). All data were analyzed using the Statistical Analysis System (SAS) version 6.09 and the Analysis of Variance (ANOVA) procedure. Means comparisons were made using Fisher’s Least Significant Difference test (LSD). There were no quality differences among the treated and untreated plots and turf quality remained above the lowest acceptable rating (a ‘6 ’). throughout the duration of the study (Table 1). Following the early post- and postemergence applications, the turf treated with Preclaim had a yellow coating. This coloration was not evident when the turf was checked for phytotoxicity three days after application (June 7 and July 15). There were no phytotoxic symptoms on any treated bluegrass. All of the herbicides provided significant crabgrass control when compared with the untreated controls. Six of the products reduced crabgrass cover by > 95% (Table 2). The oxalis and spurge data do not indicate significant control by any herbicides when compared with the untreated controls because of low numbers of these plants in the control plots (Table 3). 31 Herbicide and Growth Regulator Studies Table 1. Visual quality1 of Kentucky bluegrass treated with early post- and postemergence herbicide products for the ■ _____ Postemergence Annual Weed Control Study.____________________________________________________ Rate lb a.i./A. Timing of application June 7 June 25 July 3 July 15 July 23 July 30 Aug 8 1. Untreated control NA NA 7 7 6 7 7 7 7 2. Acclaim Extra 68.5EW1 0.06 EARLY POST 7 7 6 7 7 7 7 3. Acclaim 120EC 0.12 EARLY POST 7 7 6 7 7 7 7 4. Preclaim 370.6EC 2.06 EARLY POST 7 7 6 7 7 7 7 5. Acclaim Extra 68.5EW 0.09 POST 7 7 6 7 7 7 7 6. Acclaim 120EC 0.18 POST 7 7 6 7 7 7 7 7. Preclaim 370.6EC 3.09 POST 7 7 6 7 7 7 7 8. Dimension 1EC 0.25 POST 7 7 6 7 7 7 7 9. Dimension 1EC 0.25 + 3 fl oz POST 7 7 6 7 7 7 7 3 fl oz POST 7 7 6 7 7 7 7 Material + Trimec Plus 10. Trimec Plus 11. Dimension 1EC 0.25 + Preclaim + 3.09 POST 7 7 6 7 7 7 7 3.09 POST 7 7 6 7 7 7 7 NS NS NS NS NS NS NS 12. Preclaim L S D o.05 V isual quality was assessed on a 9 to 1 scale: 9 = best quality, 6 = lowest acceptable quality, and 1 = poorest quality. EARLY POST applications were made on June 4 and POST on July 12, 1996. NS = means are not significantly different at the 0.05 level. 32 Herbicide and Growth Regulator Studies Table 2. Percent crabgrass cover1and mean percentage reduction in crabgrass cover in Kentucky bluegrass treated with _________early post- and postemergence herbicides for the Postemergence Annual Weed Control Study.___________ Percentage crabgrass cover Rate Timing of Mean Mean July July Aug 30 cover reduction Material lb a.i./A. application 23 8 1. Untreated control NA NA 48 65 65 59 0 2. Acclaim Extra 68.5EW 0.06 EARLY POST 10 18 18 16 74 3. Acclaim 120EC 0.12 EARLY POST 10 15 15 13 77 4. Preclaim 370.6EC 2.06 EARLY POST 1 2 1 1 98 5. Acclaim Extra 68.5EW 0.09 POST 1 1 1 1 98 6. Acclaim 120EC 0.18 POST 1 1 1 1 98 7. Preclaim 370.6EC 3.09 POST 1 1 1 1 99 8. Dimension 1EC 0.25 POST 30 40 52 41 31 9. Dimension 1EC + Trimec Plus 0.25 + 3 fl oz POST 18 12 15 15 74 3 fl oz POST 27 17 20 21 64 0.25 + 3.09 POST 4 1 1 2 97 3.09 POST 1 1 2 1 98 13 12 L S D o.05 ‘These values represent the area per plot covered by crabgrass. EARLY POST applications were made on June 4 and POST on July 12, 1996. 9 11 18 10. Trimec Plus 11. Dimension 1EC + Preclaim 12. Preclaim Table 3. Number of oxalis and spurge plants1 in Kentucky bluegrass treated with early post- and postemergence herbicide products for the Postemergence Annual Weed Control Study. Rate Timing of Number of Material lb a.i./A. application Oxalis 1. Untreated control NA NA 2 Number of Spurge i 2. Acclaim Extra 68.5EW 0.06 EARLY POST 5 5 3. Acclaim 120EC 0.12 EARLY POST 6 7 4. Preclaim 370.6EC 2.06 EARLY POST 0 0 5. Acclaim Extra 68.5EW 0.09 POST 11 3 6. Acclaim 120EC 0.18 POST 7 2 7. Preclaim 370.6EC 3.09 POST 0 0 8. Dimension 1EC 0.25 POST 2 0 0.25 + 3 fl oz POST 0 0 3 fl oz POST 0 0 0.25 + 3.09 POST 0 0 3.09 POST 2 1 5 4 9. Dimension 1EC + Trimec Plus 10. Trimec Plus 11. Dimension 1EC + Preclaim 12. Preclaim LSDo.os ---------;---------------- —;---------;-----1These values represent the number of plants per plot. EARLY POST applications were made on June 4 and POST on July 12, 1996. 33 Herbicide and Growth Regulator Studies 1995 P oa annua Control in Creeping Bentgrass Greens - Year 2 Barbara R. Bingaman, NickE. Christians, and David Several herbicides were evaluated throughout the fall of 1995 and the spring of 1996 for their efficacy in controlling Poa annua in green height creeping bentgrass. The plot was located on an established 'Penncross' creeping bentgrass practice green at Veenker Memorial Golf Course in Ames, Iowa with 6080% infestation of Poa annua. The experiment was arranged in a randomized complete block design. Individual plots were 5 x 5 ft and three replications were conducted. There were six treatments including an untreated control, Turf Enhancer 2SC [Paclobutrazol (TGR)], Proturf high K fertilizer (15-0-29) + Prograss, High K fertilizer (15-0-29) + Turf Enhancer, Prograss 1EC (Ethofumesate) at two rates, and Primo 1EC (Table 1). Liquid formulations were applied using a carbon dioxide backpack sprayer equipped with #8006 nozzles at 25-30 psi.. The granular materials were applied using cardboard containers as ‘shaker dispensers’. Weather conditions were highly variable during this study. Rainfall was sporadic and temperature fluctuations were large. Supplemental irrigation was used to keep the bentgrass in good growing condition. In September and October of 1995, Turf Enhancer 2SC was applied at 8 fl oz/A and Proturf fertilizer + Turf Enhancer at 0.125 lb a.i./A. Spring 1996 applications were on April 22, June 4, and July 10. Prograss 1.5EC was applied at 0.380 and 0.560 lb a.i./A and Proturf fertilizer + Prograss at 0.380 lb a.i./A in September, October, and November 1995 and April 1996. Primo 1EC was applied in the fall of 1995 at the rate of 0.3 fl oz/1000 ft2, in April 1996 at 0.25 fl oz/1000 ft2 and in June and July at 0.30 fl oz/1000 ft2. On May 9 the plot was fertilized with Nutralene at 1/2 lb N/1000 ft2. Potassium also was applied at 1/2 lb/1000 ft2. Proturf fertilizer (15-0-30) was not applied to the untreated control plots. The first spring treatments were made April 22. Sequential applications were made June 4. The last 1996 applications were made July 10. The materials were watered in with the irrigation following each application. On April 12, green up had occurred and Poa annua germination was observed. There were obvious differences in quality among the plots on April 16. Visual quality was assessed using a 9 to 1 scale: 9 = best quality, 6 = lowest acceptable quality, and 1 = poorest quality (Table 1). Subsequent visual quality data were taken on May 9 and May 30. Poa annua control was measured by determining percentage of Poa annua cover per plot (Table 2). The first Poa annua data were taken April 16 and subsequent data were taken May 9, May 30, June 12, July 3, July 31, and August 29. Data were analyzed using the Statistical Analysis System (SAS) version 6.09 and the Analysis of Variance (ANOVA) procedure. Means were compared with Fisher’s Least Significant Difference (LSD) test. Several treatments significantly reduced turf quality on April 16, 1996 (Table 1). These reductions were likely due to loss of Poa annua during the winter in treated plots (Table 2). No other reductions of turf quality below acceptable levels were observed during the rest of the season with the exception of Primo 1EC on June 10 (Table 1). 34 Herbicide and Growth Regulator Studies Primo was the only treatment that did not significantly reduce annua during the 1996 season (Table 2). Prograss 1.5EC at 0.56 lb a.i./A was the most effective treatment with an average reduction of 81% as compared to the untreated control (47% to 9%). Turf Enhancer 2SC reduced Poa annua an average 45% without added K fertilizer and 57% with added K fertilizer. Table 1. Visual quality1of Kentucky bluegrass treated with herbicide and herbicide + fertilizer formulations in the Material 1. Untreated control Rate lb a.i./A Spring applications2 April 16 May 9 June 10 Mean quality NA NA 7 9 7 8 2. Turf Enhancer 2 SC 0.125 April, June, July 4 7 7 6 3. Proturf fertilizer + Prograss 0.380 April 5 8 8 7 4. High K fertilizer + Turf Enhancer 0.125 April, June, July 4 6 8 6 5. Prograss 1.5EC 0.380 April 5 7 7 6 6. Prograss 1.5EC 0.560 April 6 8 9 7 7. Primo 1EC 0.3003 April, June, July 7 8 5 7 1 1 1 1 L S D o.05 1Visual quality was assessed using a 9 to 1 scale: 9 = best quality, 6 = lowest acceptable quality, and 1 = poorest quality. 2 Applications were made on April 22, June 4, and July 10. 1 The rate for the April applications was 0.25 fl oz product/1000 ft2 and the rate for June and July was 0.30 fl oz product/1000 f t . Table 2. Percent Poa annua cover' in Kentucky bluegrass treated with herbicide and herbicide + fertilizer formulations in the 1995-1996 Green Height Bentgrass Poa annua Control Study. Material Rate lb a.i./A Apr 16 May 9 May 30 June 12 July 3 July 31 Aug 29 % cover Mean % cover 1. Untreated control NA 57 52 60 53 60 25 23 47 2. Turf Enhancer 2SC 0.125 20 10 48 53 17 12 22 26 3. Proturf fertilizer + Prograss 0.380 32 13 13 17 35 25 17 22 4. High K fertilizer + Turf Enhancer 0.125 17 13 22 42 22 13 15 20 5. Prograss 1.5EC 0.380 15 18 12 18 23 12 8 15 6. Prograss 1.5EC 0.560 10 12 5 7 7 8 12 9 7. Primo 1EC 0.300 60 38 57 38 53 23 20 41 14 15 19 33 21 NS NS 11 L S D o.05 ‘These percentages represent the area per plot covered by Poa annua. NS = means are not significantly different at the 0.05 level. 35 Herbicide and Growth Regulator Studies Effects of Trinexapac Ethyl on Sod Production - 1996 Barbara R. Bingaman, NickE. Christians, and David S. Gardner The impact of the growth regulator, Trinexapac ethyl, on sod production and post-harvest establishment was assessed. This study was conducted at the Iowa State University Horticulture Research Station north of Ames, Iowa. The experimental plot was ‘Vantage’ Kentucky bluegrass. The soil in this area was a Nicollet (fine-loamy, mixed, mesic Aquic Hapludoll) with 3.6% organic matter, a pH of 7.0, 2 ppm P, and 85 ppm K. The experiment was designed as a randomized complete block. There were four replications with 5 x 5 ft. individual plots and no barrier rows between replications. There were three Primo 1EC treatment regimes and an untreated control. All applications were made at 0.75 oz/1000 fit2 (the label rate for Kentucky bluegrass). Primo was applied two weeks prior to sod harvest, two weeks after sod establishment, and both two weeks prior and two weeks after (Table 1). A carbon dioxide backpack sprayer equipped with #8006 nozzles at 20-25 psi was used to apply the Primo 1EC. On June 4, the ‘two weeks before sod cutting’ treatments were applied. On June 19, the turf on the entire experimental plot was cut using a sod cutter. The sod had approximately 1.5- 2.0 in. of soil/root mass. Sod pieces were transplanted into 12 x 12 in. wooden frames. A piece of sod the size of the outside diameter of the frame was cut and the frames were placed into the resulting hole so that the frames were flush with the soil surface. The sod piece was then trimmed to fit inside the frame. The frames had 18 mesh fiberglass screen bottoms so the roots could grow through. The frames were placed back into the experimental plots so the sod would establish. Four frames were used in each plot, one in each of four quadrants. One frame from each plot was randomly chosen and ‘pulled’ on each of four data collection dates. The plot was watered thoroughly upon completion and watered as needed to prevent the sod from drying. On July 3, the ‘two weeks after sod establishment’ treatments were made and the first set of sod frames were sampled. Steel cables attached to a special hydraulic sod pulling apparatus were attached to screw hooks placed on each side of the frames. Pressure was applied to the lifting apparatus and the frames were ‘pulled’. The tensile strength required to pull the roots from the soil was measured in foot pounds and recorded on a gauge. The remaining three sets of frames were harvested at 2week intervals on July 19, July 31, and August 15. Turf quality was assessed using a 9 to 1 scale: 9 = best quality, 6 = lowest acceptable quality, and 1 = poorest quality. Visual quality data were taken on July 3, July 19, July 25, July 31, and August 15 (Table 1). Sod establishment and root ‘knitting’ were measured as tensile strength in foot pounds using a hydraulic sod pulling apparatus (Table 2). Data were analyzed using the Statistical Analysis System (SAS) version 6.09 and the Analysis of Variance (ANOVA) procedure. Means were compared with Fisher’s Least Significant Difference test (LSD). Significant differences in turf quality were found on July 25 and August 15. The untreated controls and bluegrass treated with Primo two weeks before sod cutting (treatment 2) had significantly better 36 Herbicide and Growth Regulator Studies mean quality than turf treated with Primo two weeks after sod cutting and turf treated two weeks before and after cutting. On July 3, the tensile strength of sod treated with Primo two weeks before sod cutting was significantly higher than the untreated controls and sod treated with Primo two weeks after establishment (Table 3). On July 19, the tensile strengths were similar for treated and untreated sod On July 31, the strengths were not significantly different and were almost equal for sod treated with Primo two weeks before, sod treated two weeks before and after, and untreated sod. On August 15, sod treated with Primo two weeks before and after had significantly higher tensile strength than the other treated and untreated sod. Table 1. Visual quality1 of Kentucky bluegrass sod growing in frames in the 1996 Primo Sod Production Study. Materials Rate [oz product] Timing of application July 3 July 19 July 1. Untreated control NA NA 0.75 0.75 0.75 2 wks before 7 7 8 2 . Primo 1EC 7 7 7 7 NA 3. Primo 1EC 4. Primo 1EC 2 wks after 2 wks before & 2 wks after LSDq05 July 31 Aug. 6 8 7 7 7 7 7 6 6 6 6 6 6 6 6 7 6 NA 0.5 NA 0.4 0.1 25 15 Mean quality Two weeks prior to sod cutting treatments were applied June 4. Sod was cut and put into frames on June 19. Two weeks after sod establishment treatments were applied July 3. 1 Visual quality was assessed using a 9 to 1 scale: 9 = best quality, 6 = lowest acceptable quality, and 1 = poorest quality. NA = LSD test not applicable because there is no mean square error (no variance among reps). Table 2. Root tensile strength and knitting of Kentucky bluegrass sod growing in frames in the 1996 Primo Sod Production Study measured by the number of pounds (PSI) required to pull 1 ft2 frames. Tensile strength (PSI) Materials Rate [oz product] Timing of application July 3 July 19 July 31 Aug 15 Mean strength 1. Untreated control NA NA 146 273 335 274 257 2. Primo 1EC 0.75 2 wks before 188 271 333 333 281 3. Primo 1EC 0.75 2 wks after 129 243 263 303 234 4. Primo 1EC 0.75 2 wks before & 2 wks after 178 280 320 460 309 40 NS NS 133 NS LSDq05 Two weeks prior to sod cutting treatments were applied June 4. Sod was cut and put into frames on June 19. Two weeks after sod establishment treatments were applied July 3. NS = means are not significantly different at the 0.05 level. 37 Herbicide and Growth Regulator Studies Effects of Trinexapac Ethyl (Primo) on Perennial Ryegrass Seedlings - 1996 Barbara R. Bingaman, Nick E. Christians, and David S. Gardner The effects of the growth regulator, trinexapac ethyl, were evaluated on the establishment and early growth of seedling perennial ryegrass. This study was conducted at the Iowa State University Horticulture Research Station north of Ames, Iowa. The experimental plot was an area where Kentucky bluegrass sod was cut. The soil in this plot was a Nicollet (fine-loamy, mixed, mesic Aquic Hapludoll) with 2.8% organic matter, a pH of 6.9, 5 ppm P, and 71 ppm K. The experiment was designed as a randomized complete block. There were three replications with 5 x 5 ft individual plots laid out a single row measuring 90 x 5 ft. Primo 1EC was applied at the same rate five different times throughout the growth and establishment of the ryegrass. All Primo applications were made at 1.0 oz/1000 ft2, the requested rate for perennial ryegrass. Treatments included an application of Primo at seeding, 1 week after seeding (1 WAS), and subsequent treatments at 2, 3, and 4 weeks after seeding. An untreated control was included for comparisons (Table 1). To prepare the plot for seeding, it was sprayed with Roundup, tilled and raked. Phosphorous was applied at 1 lb P20 4/1000 ft2 and nitrogen was applied at 1/2 lb/1000 ft2 prior to seeding. Perennial ryegrass was seeded at 4 lbs/1000 ft2. A PAR 3 ryegrass blend from D & K Products, Des Moines, IA was used. It contained 33.6% Palmer II, 33.6% Prelude II, and 28.8% Repell II. The origin of these cultivars was Oregon and the germination was rated at 90%. It was tested 1/96 and was lot 40024-1. Seeding was performed on June 26, 1996. Following seeding, the plot was rolled and watered. Supplemental irrigation was employed to keep the plot moist for good germination. Ryegrass emergence was observed on July 3. On this same date the 1 WAS treatment was made. Rainfall occurred on July 7 (Table 2). The 2 WAS application was made on July 10, the 3 WAS on July 19, the 4 WAS on July 25 (delayed because of adverse weather and 1996 Turfgrass Field Day). The initial fresh clipping weight, visual quality, and percent ryegrass cover data were taken on July 30. Subsequent data were taken on August 8, August 23, and September 5. Visual quality was assessed using a 9 to 1 scale: 9 = best quality, 6 = lowest acceptable quality, and 1 = poorest quality (Table 1). Clipping weights were measured as grams fresh tissue (Table 2). Mowing height for collecting clippings was 2 inches. Ryegrass cover was determined by a visual estimation of the percentage of ryegrass cover in each plot (Table 3). Data were analyzed using the Statistical Analysis System (SAS) version 6.09 and the Analysis of Variance (ANOVA) procedure. Means were compared with the Fisher’s Least Significant Difference (LSD) test. Primo had no detrimental effects on either quality (Table 1) or percentage cover (Table 3) of perennial ryegrass. There were no significant reductions in growth of the seedling ryegrass (Table 2) although the 4 WAS treatment did numerically reduce clipping weights from 137 g in the control to 93 g in the treated plots. 38 Herbicide and Growth Regulator Studies Table 1. Visual quality1 of perennial ryegrass treated with Primo 1EC in the 1996 Primo Seedling study. Materials July 30 August 8 August 23 September 5 Mean Quality 1. Untreated control 8 8 7 7 7.5 2. Primo 1EC at seeding 8 8 7 7 7.5 3. Primo 1EC 1 WAS2 8 8 7 7 7.5 4. Primo 1EC 2 WAS2 8 8 7 7 7.5 5. Primo 1EC 3 WAS2 8 8 7 7 7.5 6. Primo 1EC 4 WAS2 8 8 7 7 7.5 NS NS NS NS NS LSD oos 1 1 Visual quality was assessed using a 9 to 1 scale: 9 = best quality, 6 = lowest acceptable quality, and 1 = poorest quality. 2 WAS = weeks after seeding. Perennial ryegrass was seeded and treatment 2 was applied on June 26, treatment 3 on July 3, treatment 4 on July 10, treatment 5 on July 19, and treatment 6 on July 25, 1996. NS = means are not significantly different at the 0.05 level. Table 2. Clipping weights1 of perennial ryegrass treated with Primo 1EC in the 1996 Primo Seedling Materials July 30 August 8 September 5 Mean Weight Total Weight grams fresh tissue 1. Untreated control 27 6 74 46 137 2. Primo 1EC at seeding 31 40 74 48 145 3. Primo 1EC 1 WAS2 31 35 70 46 137 4. Primo 1EC 2 WAS2 24 34 78 45 135 5. Primo 1EC 3 WAS2 34 34 53 40 121 6. Primo 1EC 4 WAS2 31 15 47 31 93 LSDoos NS NS NS NS NS Clipping weights are expressed as grams fresh tissue. * WAS = weeks after seeding. Perennial ryegrass was seeded and treatment 2 was applied on June 26, treatment 3 on July 3, treatment 4 on July 10, treatment 5 on July 19, and treatment 6 on July 25, 1996. NS = means are not significantly different at the 0.05 level. 39 Herbicide and Growth Regulator Studies Table 3. Percentage of perennial ryegrass cover in plots treated with Primo 1EC in the 1996 Primo Seedling study. Materials July 30 August 8 August 23 September 51 Mean ryegrass cover % cover 1. Untreated control 80 83 90 83 84 2. Primo 1EC at seeding 80 83 90 92 86 3. Primo 1EC 1 WAS2 80 85 90 83 85 4. Primo 1EC 2 WAS2 80 82 90 77 82 5. Primo 1EC 3 WAS2 80 87 90 90 87 6. Primo 1EC 4 WAS2 80 85 90 92 87 LSDo.os NS NS NS NS NS 1 Differences in ryegrass cover are attributable to the percentage of weed cover. 2 WAS = weeks after seeding. Perennial ryegrass was seeded and treatment 2 was applied on June 26, treatment 3 on July 3, treatment 4 on July 10, treatment 5 on July 19, and treatment 6 on July 25, 1996. NS = means are not significantly different at the 0.05 level. 40 Herbicide and Growth Regulator Studies The Effect of Betasan on Four Creeping Bentgrass Cultivars Maintained at Green Height Barbara R. Bingaman, Nick E. Christians, and David S. Gardner Betasan 4LF was evaluated for phytotoxicity on green height creeping bentgrass. This study was conducted at the Iowa State University Horticulture Research Station north of Ames, Iowa. The experiment was located in creeping bentgrass grown in native soil with a pH of 7.25, 5 lb/acre P, and 60 lb/acre K. Four experimental plots were set up, one in each of four creeping bentgrass cultivars (Penncross, Penneagle, SR-1019, and SR-1020) mowed at 0.3 in. Each experiment was arranged in a randomized complete block design. Individual plots were 5 x 5 ft with three replications. There were three treatments including an untreated control. Betasan 4LF was applied at 20 pt. product/A initially and sequentially at 15 pt. product/A (Table 1). Double applications at these same rates and with the same timing were included to simulate overlap. The assignment of treatments to plots was randomized. Betasan 4LF was applied using a carbon dioxide backpack sprayer equipped with #8006 nozzles and a spray pressure of 30 psi. The plots were irrigated with 0.5 - 1.0 inch of water immediately after applications. Supplemental irrigation was used to maintain the bentgrass in good growing condition. The initial treatments were made May 29, 1996. Sequential applications were made on August 29. The plots were checked for turf quality and phytotoxicity periodically beginning June 3. Subsequent data were taken on June 10, June 26, July 3, July 18, August 8, August 29, September 5, and September 11. Visual quality was assessed using a 9 to 1 scale: 9 = best quality, 6 = lowest acceptable quality, and 1 = poorest quality (Table 1). Phytotoxicity data were assessed using a 9 to 1 scale: 9 = no damage, 8 = 10% brown, 7 = 20% brown, and 6 = 30% brown turf within the plot (Table 2). Data were analyzed with the Statistical Analysis System (SAS) version 6.09 and the Analysis of Variance (ANOVA) procedure. Means were compared with Fisher’s Least Significant Difference (LSD) test. There were no signs of phytotoxicity on any of the treated bentgrass plots following the initial applications (Table 1). On September 5, seven days after the sequential treatments, there was some general browning on the entire green height bentgrass area including the experimental plots and surrounding areas. In the Penneagle plot, a more pronounced browning appeared to correspond with individual plots and to be a treatment effect. These symptoms were considered as possible phytotoxicity (Table 2). By September 11, the quality of the Penneagle was uniform among the treated and untreated plots. No other phytotoxicity was detected. 41 Herbicide and Growth Regulator Studies Table 1. Visual quality1of green height creeping bentgrass treated with Betasan 4LF in the 1996 Green Height ________ Bentgrass Phytotoxicity Study.___________________________________________________________ Rate June June June July July Aug Sept Sept Mean Material (pts product/A) 3 10 26 3 18 8 5 11 quality initial/sequential SR-1019 1. 2. 3. Untreated control Betasan 4LF Betasan 4LF LSDo NA 20/15 40/302 9 9 9 NS 8 8 8 NS 8 8 8 NS 8 8 8 NS 9 9 9 NS 9 9 9 NS 6 6 6 NS 7 7 7 NS 8 8 8 NS NA 20/15 40/302 9 9 9 NS 8 8 8 NS 8 8 8 NS 8 8 8 NS 9 9 9 NS 9 9 9 NS 6 6 6 NS 7 7 7 NS 8 8 8 NS NA 20/15 40/302 9 9 9 NS 8 8 8 NS 8 8 8 NS 8 8 8 NS 9 9 9 NS 9 9 9 NS 6 6 6 NS 7 7 7 NS 8 8 8 NS NA 20/15 40/302 9 9 9 NS 8 8 8 NS 8 8 8 NS 8 8 8 NS 9 9 9 NS 9 9 9 NS 6 6 6 NS 7 7 7 NS 8 8 8 NS 05 SR-1020 1. 2. 3. Untreated control Betasan 4LF Betasan 4LF LSD 0.05 Penncross 1. 2. 3. Untreated control Betasan 4LF Betasan 4LF LSD 0.05 Penneagle 1. 2. 3. Untreated control Betasan 4LF Betasan 4LF LSD 0 0 5 ‘Visual quality was assessed using a 9 to 1 scale: 9 = best, 6 = lowest acceptable, and 1 = worst quality. 2Twice the Betasan and water were applied to plots receiving treatment 3 Initial applications were made on May 29 and sequential on August, 29, 1996. NS = means are not significantly different at the 0.05 level. Table 2. Possible phytotoxicity1detected September 5 in green height creeping bentgrass treated with Betasan _________ 4LF in the 1996 Green Height Bentgrass Phytotoxicity Study.____________ ____________________ Material Rate (pts product/A) initial/sequential2 September 5 SR-1019 1. 2. 3. Untreated control Betasan 4LF Betasan 4LF NA 20/15 40/30 9 9 9 NS NA 20/15 40/30 9 9 9 NS NA 20/15 40/30 9 9 9 NS NA 20/15 40/30 8 6 6 NS L S D o.05 SR-1020 1. 2. 3. Untreated control Betasan 4LF Betasan 4LF LSDo.os Penncross 1. 2. 3. Untreated control Betasan 4LF Betasan 4LF L S D oos Penneagle 1. 2. 3. Untreated control Betasan 4LF Betasan 4LF LSDo 05 1 Phytotoxicity was assessed using a 9 to 1 scale: 9 = no phyto, 8 = 10% brown, 7 = 20% brown, 6 = 30% brown turf per plot. 2 Twice the Betasan and water were applied to plots receiving treatment 3. NS = means are not significantly different at the 0.05 level. 42 Herbicide and Growth Regulator Studies The Effect of Tupersan on Four Creeping Bentgrass Cultivars Maintained at Fairway Height Barbara R. Bingaman, Nick E. Christians, and David S. Gardner Tupersan 50WP was evaluated for phytotoxicity on creeping bentgrass maintained at fairway height. This study was conducted at the Iowa State University Horticulture Research Station north of Ames, Iowa. The soil in this area up was a Nicollet (fine-loamy, mixed, mesic Aquic Hapludoll) with a pH of 7.25, 5 lb/acre P, and 60 lb/acre K. Four experimental plots were set up, one in each of four creeping bentgrass cultivars (Penncross, Penneagle, SR-1019, and Dominant) mowed at 0.5 in. Each experiment was arranged in a randomized complete block design. Individual plots were 5 x 5 ft with three replications. There were three treatments including an untreated control. Tupersan 50WP was applied at 24 lb product/A and in double applications at 24 lb product/A per application to simulate overlap (Table 1). The assignment of treatments to plots was randomized. Tupersan was applied using a carbon dioxide backpack sprayer equipped with #8006 nozzles and a spray pressure of 30 psi. The plots were irrigated with 0.5 - 1.0 inch of water immediately after application. Supplemental irrigation was used to maintain the bentgrass in good growing condition. The initial treatments were made May 29, 1996. The plots were checked for turf quality and phytotoxicity periodically beginning June 3. Subsequent data were taken June 10, June 26, July 3, July 18, August 8, August 29, September 5, and September 11. Visual quality was assessed using a 9 to 1 scale: 9 = best quality, 6 = lowest acceptable quality, and 1 = poorest quality (Table 1). Data were analyzed with the Statistical Analysis System (SAS) version 6.09 and the Analysis of Variance (ANOVA) procedure. Means were compared with Fisher’s Least Significant Difference (LSD) test. May 30, the plots treated with Tupersan still retained a slight whitish color from the material. This color was still visible on June 3 but by June 10 was no longer evident. At no time during the study were there any signs of phytotoxicity on any of the treated plots (Table 1). 43 Herbicide and Growth Regulator Studies Table 1. Visual quality1of fairway height creeping bentgrass in the 1996 Bentgrass Phytotoxicity Study. Material Rate (lbs product/A2) June 3 June 10 June 26 July 3 July 18 Aug 8 Sept 5 Sept 11 Mean quality NA 24 48' 7 7 7 7 7 7 8 8 8 8 8 8 9 9 9 9 9 9 8 8 8 8 8 8 8 8 8 NS NS NS NS NS NS NS NS NS 7 7 7 7 7 7 8 8 8 8 8 8 9 9 9 9 9 9 8 8 8 8 8 8 8 8 8 NS NS NS NS NS NS NS NS NS 7 7 7 7 7 7 8 8 8 8 8 8 9 9 9 9 9 9 8 8 8 8 8 8 8 8 8 NS NS NS NS NS NS NS NS NS 7 7 7 7 7 7 8 8 8 8 8 8 9 9 9 9 9 9 8 8 8 8 8 8 8 8 8 NS NS NS NS NS NS NS NS NS SR-1019 1. 2. 3. Untreated control Tupersan 50WP Tupersan 50WP LSDo os Dominant 1. 2. 3. Untreated control Tupersan 50WP Tupersan 50WP NA 24 481 LSDo.05 Penncross 1. 2. 3. Untreated control Tupersan 50WP Tupersan 50WP NA 24 481 L S D o.05 Penneasle 1. 2. 3. Untreated control Tupersan 50WP Tupersan 50WP LSD 0.05 NA 24 481 1 Visual quality was assessed using a 9 to 1 scale: 9 = best quality, 6 = lowest acceptable quality, and 1 = poorest quality. 2 Twice the Tupersan and water were applied to plots receiving treatment 3. NS = means are not significantly different at the 0.05 level. 44 Herbicide and Growth Regulator Studies Non-selective Herbicide Demonstration Study Barbara R. Bingaman, Nick E. Christians, and David S. Gardner Finale from AgrEvo, Roundup from Monsanto, and Reward from Zeneca were screened in a nonreplicated study for efficacy of non-selective herbicides in creating even border areas. This trial was conducted at the Iowa State University Horticulture Research Station north of Ames, Iowa as a demonstration plot for the 1996 Turfgrass Field Day. The experimental area consisted of Kentucky bluegrass surrounding permanent ornamental grass beds. Finale, Roundup, and Reward were applied to approximately 6-inch wide border strips around individual ornamental plantings. Finale was applied at a rate of 4.0 oz a.i./A, Roundup at 2.7 oz a.i./A, and Reward at the label rate of 20 ml product/gal water. The materials were applied with a carbon dioxide backpack sprayer equipped with #8006 nozzles at 25-30 psi. Applications were made July 3, July 12, and July 15. These dates correspond with 14, 5, and 2 days, respectively, before Field Day on July 18. A survey of the experimental area was made prior to treatment and the bluegrass in the border areas was uniform in color and overall quality. Data on the overall condition of the plants within the treated area and the evenness of the border areas were taken on July 10, July 15, July 25, and August 20 (Table 1). All materials worked satisfactorily and produced even border strips with brown, dead grass in approximately 12 days (Table 1). Even, brown, dead borders were observed on July 15 in all plots treated on July 3 (Table 1). The herbicides produced different phytotoxic symptoms. Finale treated bluegrass exhibited severe chlorosis before turning orange-brown and dying. Grass treated with either Roundup or Reward turned from healthy green to shades of brown. Border areas treated with Reward were not as persistent as those treated with either Finale or Roundup. By July 25 (five days after Field Day), regrowth of green turf was present in the border areas treated with Reward on July 3. On August 20, (33 days after Field Day) all grass in the Reward treated border areas had regrown but there was no regrowth of either turfgrass or weeds in the areas treated with either Finale or Roundup (Table 1). 45 Herbicide and Growth Regulator Studies © o CN +-» CO G o Z NO ON ON 00 G ■< X■*—> * 3 CD X a X & G G X X G G £ « x" . 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G <ü X X G g ©« CD -3 3 1G G ’t-j , •3 5 :3 i1- 1 Zr> 3 >— i (N Z' 3 • —s 1 2 ,o CD Q co X Æ < Z (N (N (N to CD x ’o 2>, xft X G u CD CD X 3 co o '4—» X G -2 GCD 3 h > © X G X G X) £ to< CD 3 o X G CD (N X 0 3p X G CD X CO 4-» G d 3 J CD 00 oc x (D ’i 0 Turfgrass Disease Research Nutrient Salts and Toxicity of Black-layer Clinton F. Hodges and Douglas A. Campbell Black-layer or black-plug layer is a common disorder of high-sand-content golf greens characterized by development of an interrupted or continuous subsurface blackened layer in the sand (2, 4, 5, 6). The layer is typically associated with noxious odors, and the turf may show symptoms of chlorosis, wilting, thinning, and eventual death. The layer may be initiated by a consortium of bacteria or by cyanobacteria that produce biofilms in the sand that impede the drainage of water (4, 6). The biofilm creates anaerobic conditions and provides organic matter that support the proliferation of sulfate-reducing bacteria and the subsequent development of the black-layer. The precise cause of death of creeping bentgrass growing on black-layered sand is unknown. The potential production of hydrogen sulfide by sulfate-reducing bacteria may be one of the toxic components of black-layer development (1, 7). It is not uncommon, however, to find healthy grass growing on black-layered sand. This suggests that the toxicity of the layers may be variable. It has also been observed that the roots of A. palustris can grow through and clear the black-layer formed by the interaction of cyanobacteria and sulfate-reducing bacteria (5). Studies on the physical structure of black-layer have revealed vertical cavities in the layer through which grass roots grow with at least 3-mm of clear sand between the root and the blackened sand (2). There are two primary prerequisites for the formation of black-layer by sulfate-reducing bacteria in high-sand-content greens: anaerobic sites in the sand and metabolizable organic matter. The nature of the toxicity of black-layer is unclear and may be variable and/or dependent on factors associated with the site or the management practices applied to the turf. Preliminary research has been initiated to determine if various elemental substances commonly used on golf greens can influence the toxicity of black-layer formed by the interaction of cyanobacteria and sulfate-reducing bacteria. Nutrients and Toxicity Black-layered sand was produced from the combination of cyanobacteria of the genera Nostoc, Oscillatoria, or Phormidium combined with the sulfate-reducing bacterium Desulfovibrio desulfuricans. All black-layered sand columns and the non-black-layered control columns received the same standard salt solution (3) supplemented with iron, sulfur, or lime. Salts. Dry weight loss in the black-layered sand was 51% of the no-organism salts control in response to the combinations of Nostoc + D. desulfuricans, 59% for Phormidium + D. desulfuricans, and 79% for Oscillatoria + D. desulfuricans. These observations suggest that the toxicity of black­ layered sand formed from the interaction of different species of cyanobacteria and D. desulfuricans can differ. These preliminary observations indicate that the cyanobacterium Nostoc in combination with D. desulfuricans produces a more toxic black-layer than that resulting from other cyanobacteria. D. desulfuricans alone failed to produce a black-layer and had no effect on plant growth relative to the no-organism salts control. Salts + sulfur. Dry weight of plants from the salts + sulfur no-organism control did not differ from that from the no-organism salts control. All combinations of cyanobacteria and D. desulfuricans moderately decreased dry weight relative to the no-organisms sulfur control. All decreases were less than that in response to the same organism combinations in the salts control. The combination of Nostoc + D. desulfuricans stilled caused the greatest decrease at 78% of the no-organisms sulfur control. D. desulfuricans alone in nonblack-layered sand responded to the sulfur by decreasing dry weight to 55% of the no-organism sulfur control. This observation suggests that D. desulfuricans can damage turfgrasses long before there is any visible sign of black-layer formation in the sand. 47 Turfgrass Disease Research Salts + iron. Dry weight of plants from the salts + iron no-organism control increased dramatically relative to that of the no-organism salts control and salts + sulfur control. Dry weight of the grasses in the no-organism salts + iron control were about 140% greater than that in the no-organisms salts control and salts + sulfur control. The various combinations of cyanobacteria and D. desulfuricans decreased dry weight relative to the stimulated plants in the no-organisms salts + iron control. Nostoc + D. desulfuricans caused the greatest decrease in dry weight (54%). D. desulfuricans alone in nonblack-layered sand responded to the iron by decreasing dry weight to 54% of the no-organism salts + iron control. Iron also increased the intensity of the black coloration of the black-layer; the intensity of blackening, however, was not necessarily correlated with an increase in toxicity of the layer. Salts + lime. Dry weight of plants from the salts + lime no-organism control was less than that from any of the other no-organism controls (salts, sulfur, and iron). This response was believed due to a pH that reach 9.0 or higher. Plant dry weight increased in black-layered sand produced by the combinations of Oscillatoria, Phormidium, or Nostocwith D. desulfu respectively, of the no-organisms salts + lime control. However, these increases in dry weight were still substantially lower than that of the same organism combinations in the salts, sulfhr, and iron no organisms controls. Hence, the effect of the lime on the dry weight of plants growing in black-layer was equal to or less than those growing in sulfur or iron treatments. Root Growth and Black-layer Persistence All plants transplanted into black-layered sand columns survived. Roots of plants growing in blackened sand that received the salts control, salts + sulfur, salts + iron, and salts + lime produced clear channels in the sand that surrounded roots as they grew downward in the column. By the end of the 10-wk growing period the only blackened sand occurred in the bottom of the sand columns below the tips of the extending roots. The blackened region below the root tips in sand columns receiving salts + iron remained intensely black as compared with the sand columns receiving the salts control, salts + sulfur, or salts + lime. The clearing of blackened sand by A. palustris roots has been observed in previous studies (2, 5). Cullimore et al. (2) showed that the physical structure of black-layer consisted of a series of vertical columnar structures and lateral plates. It was further observed that vertical cavities were present, through which roots grew with at least a 3-mm zone of clear sand between the root and the blackened sand. The observations of roots growing through black-layer or clearing black-layered sand suggest that the toxicity of black-layers may be variable. References 1. 2. 3. 4. 5. 6. 7. Brendt, W. L., and J. M. Vargas, Jr. 1992. Elemental sulfur lowers redox potential and provides sulfide in putting greens. HortScience 27:1188-1190. Cullimore, D. R., Nilson, S., Taylor, S., and K. Nelson. 1990. Structure of black plug layer in a turfgrass putting sand green. J. Soil Water Conserv. 45:657-659. Hoagland, D.R., and D. I. Arnon. 1950. The water-culture method for growing plants without soil. Calif. Agric. Exp. Stn. Circ. 347, Univ. Calif., Berkeley. Hodges, C. F. 1992. Interaction of cyanobacteria and sulfate-reducing bacteria in subsurface black-layer formation in high-sand content golf greens. Soil Biol. Biochem. 24:15-20. Hodges, C. F. 1992. Growth of Agrostis palustris in subsurface black-layered sand induced by cyanobacteria and sulfate-reducing bacteria. Plant Soil 142:91-96. Linderbach S. K. and D. R. Cullimore. 1989. Preliminary vitro observations on the bacteriology of the black plug layer phenomenon associated with the biofouling of golf greens. J. Appl. Bacteriol. 67:11-17. Postgate J. R. 1984. The sulfate-reducing bacteria. Cambridge University Press, Cambridge. 48 Turfgrass Disease Research Evaluation of Fungicides for Control of Brown Patch in Creeping Bentgrass - 1996 Mark L . G Trials were conducted at Veenker Memorial Golf Course on the campus of Iowa State University. Fungicides were applied to creeping bentgrass maintained at 5/32-inch cutting height, using a modified bicycle sprayer at 30 psi and a dilution rate of 5 gal/1000 ft2. The experimental design was a randomized complete block with four replications. All plots measured 4 ft x 5 ft. All plots were surrounded by 1-fit-wide strips of untreated turf in order to help create uniform disease pressure. Fungicide applications began on June 12. Subsequent applications were made at specified intervals on June 25 and July 3, 10, and 24. Brown patch symptoms were first observed on June 22. Disease development, expressed as percent diseased area per plot, increased gradually in the untreated check during July, becoming moderate by the end of the month. Because of plot-to-plot variability, no fungicide treatments exhibited significantly (LSD, P < 0.05) more or less disease than the untreated check. However, significant differences among various sprayed treatments were observed on each rating date. No phytotoxicity symptoms were observed during the trial. Table 1. 1996 Brown Patch Trial, Veenker Memorial Golf Course, Iowa State University______________________ Trt# Company none i Rate per Interval Product untreated check 1000 ft2 fdavsi 3 oz 2 AgrEvo ProStar 50 WP 3 AgrEvo ProStar Plus 50 WP Diseased area (% of plot) 6/22 5.0 7/10 7/16 5.5 10.5 7/30 16.3 21 0.5 3.0 7.8 8.8 2.5 oz 28 8.0 6.0 5.3 10.0 (pkg w/Bayleton 50 WP) 4 Am Vac Amv 41 F 2 fl oz 14 4.0 1.5 11.0 11.3 5 AmVac Amv 41 F 4 fl oz 14 2.0 2.5 14.5 18.8 6 AmVac Amv 53 WDG 2 oz 14 3.0 1.3 8.8 12.5 7 AmVac Amv 53 WDG 4 oz 14 3.5 5.5 14 23.8 8 AmVac ParFlo 6 F 3 fl oz 14 0.8 1.8 1.3 12.0 9 Zeneca Heritage 50 WDG 0.2 oz 14 0.8 1.8 1.3 12.0 10 Zeneca Heritage 50 WDG 0.3 oz 21 2.5 2.0 6.3 11.3 11 Zeneca Heritage 50 WDG 0.4 oz 28 2.5 1.8 5.0 12.5 12 Rhone-Poulenc EXP 10715A 80 WG 4 oz 14 1.8 7.8 5.8 12.5 + Dithane 75 WG (Dithane DF) 8 oz 14 0.8 2.8 6.5 11.3 14 3.3 3.3 3.0 6.3 13 Rhone-Poulenc EXP 10715A 80 WG 8 oz + Dithane 75 WG (Dithane DF) 14 Rhone-Poulenc 8 oz 4 oz EXP 10704A 80 WP + Dithane 75 WG (Dithane DF) 49 4 oz l e a Turfgrass Disease Research Trt# Company 15 Rhone-Poulenc 16 Rhone-Poulenc Rate per Interval 1000 ft2 8 oz (days) 6/22 2.3 7/10 7/16 7/30 14 2.5 10 15.5 Chipco Aliette 80 WDG 4 oz 14 1.0 7.8 9.5 8.3 + Fore 50 WP 8 oz Product EXP 10715A 80 WG Diseased area (% of plot) 17 Rhone-Poulenc Chipco 26019 FLO 3 fl oz 14 1.3 1.3 3.0 11.3 18 Rhone-Poulenc Chipco 26019 FLO 4 fl oz 14 0.3 1.0 6.5 22.5 19 Rhone-Poulenc Chipco 26019 WDG 1.5 oz 14 1.8 2.5 14.5 20 20 Rhone-Poulenc Chipco 26019 WDG 2.0 oz 14 1.0 4.5 5.3 17.5 21 Terra Thalonil 90 DF 3.5 oz 14 1.5 2.3 6.8 7.5 22 Terra Thalonil 4 L 6 fl oz 14 2.0 1.0 3.3 7.5 23 Terra TRA 0106 (Thalonil 6)+C48 4 fl oz 14 0.5 3.0 3.0 6.3 24 Bayer Lynx 25 DF 1 oz 21 1.3 5.5 9.5 21.3 25 Bayer Lynx 250 EW 28.4 ml 21 2.5 5.5 9.5 21.3 26 Bayer Bayleton 25 DF 1 oz 21 1.8 3.8 6.8 6.3 3.8 oz 14 3.5 2.8 4.3 7.5 (Bayleton 25% T/O) 27 ISK Biotech Daconil Ultrex 28 ISK Biotech Daconil Weather Stik 4.1 fl oz 14 1.0 2.5 5.0 11.3 29 ISK Biotech Daconil Zn (Bravo Zn) 6.0 fl oz 14 2.0 7.8 9.0 22.5 30 ISK Biotech IB 11522 4.0 oz 14 0.3 3.0 5.3 11.3 31 ISK Biotech IB 12231 4.7 oz 14 2.3 10 10.8 18.8 32 ISK Biotech Daconil Ultrex 3.8 oz 14 1.5 4.5 6.0 7.5 + Aliette 80 WDG 4.0 oz 14 0.3 2.5 8.5 11.3 14 1.3 3.8 7.8 13.8 14 0.8 2.0 2.8 8.8 21 0.3 1.3 3.7 5.0 33 34 ISK Biotech ISK Biotech Daconil Zn 6.0 fl oz + Aliette 80 WDG 4.0 oz Daconil Ultrex 3.8 oz + IB 10813 35 36 Rohm & Haas Rohm & Haas 0.5% v/v Eagle (RH 3866 40 WP) 0.6 oz + Fore 6.0 oz Fore 6.0 oz + Prostar 50 WP 2.0 oz 37 Rohm & Haas Eagle (RH 3866 40 WP) 0.6 oz 21 0.8 4.0 11.5 13.8 38 Rohm & Haas Eagle (RH 3866 40 WP) 1.2 oz 28 8.5 4.3 4.0 13.8 14.6 5.4 19.8 6.2 49.2 9.8 141.2 16.6 M SE1 LSD2 U 'Mean square error, df = 111 on 6/22 and 7/10, df = 110 on 7/16 and 7/30. n = 4. 2Least significant difference. P < 0.05. 50 Turfgrass Disease Research Evaluation of Fungicides for Control of Dollar Spot in Penncross Creeping Bentgrass - 1996 Mark L. Gleason Trials were conducted at the Turfgrass Research Area of Iowa State University’s Horticulture Research Station north of Ames, Iowa. Fungicides were applied to Penncross creeping bentgrass maintained at 5/32-inch cutting height, using a modified bicycle sprayer at 30 psi and a dilution rate of 5 gal/1000 ft2. The experimental design was a randomized complete block with four replications. All plots measured 4 ft x 5 ft. After inoculation of the entire plot with pathogen-infested rye grain on June 10, spray applications began on June 18. Subsequent applications were made at specified intervals on July 2, 9, 16, and 30. Dollar spot symptoms appeared in the plot within nine days after the first spray treatment. Disease development was moderate during July. On July 10, the only treatments that did not exhibit significantly (LSD, P < 0.05) fewer infection centers than the untreated control were AMV 53 WDG at 4 oz rate and Daconil Zn (6 fl oz) + Aliette 80 WDG (4 oz). On July 24, the only treatments that did not exhibit significantly fewer infection centers than the untreated control were AMV 53 WDG at 4, 6, and 8-oz rates, Rizolex 75 WP at 2.5 oz, Thalonil 4L at 6 fl oz, and two combination treatments: Chipco 26019 FLO (2 fl oz) + Heritage 50 WG (0.2 oz) and Chipco 26019 FLO (2 fl oz) + Daconil 2787 (3 fl oz). No phytotoxicity symptoms were observed during the trial. Table 1. 1996 Dollar Spot Trial, Iowa State University Horticulture Research Station Trt# Company 1 none Product Rate per Interval 1000 ft2 (days) 6/27 36.8 7/10 7/24 untreated check # of infection centers/plot 62.8 115.5 2 AmVac Amv 41 F 8 fl oz 14 8.3 10.3 17.0 3 AmVac Amv 41 F 10 fl oz 14 25.8 12.5 19.3 4 AmVac Amv 41 F 12 fl oz 14 12.8 7.5 14.3 5 AmVac Amv 53 WDG 4 oz 14 41.3 37.5 110.0 6 AmVac Amv 53 WDG 6 oz 14 32.5 30.8 67.5 7 AmVac Amv 53 WDG 8 oz 14 31.3 20.0 76.3 8 AmVac ParFlo 6 F 8 fl oz 14 7.5 11.5 49.0 9 Rhone-Poulenc EXP 10702A 2 SC 4 fl oz 14 6.3 3.0 9.8 14 0.5 1.5 1.3 14 10.0 5.8 10.8 10 11 Rhone-Poulenc Rhone-Poulenc + Chipco Aliette WDG 4 oz EXP 10715A 80 WG 4 oz + EXP 10702A 2 SC 4 fl oz Daconil Ultrex 82.5 WG 3 oz + EXP 10715A 80 WG 4 oz 4 oz 14 20.0 26.3 43.8 4 fl oz 14 9.3 20.0 31.3 12 Rhone-Poulenc EXP 10715A 80 WG 13 Rhone-Poulenc Chipco 26019 FLO 14 Sandoz Sentinel 40 WG, 0.167 oz 14 8.8 1.5 3.3 Daconil Ultrex 82.5 WDG1 15 Sandoz Sentinel 40 WG 3.8 oz 0.167 oz 21 3.8 2.8 3.0 + Rizolex 75 WP 2.5 oz 51 Turfgrass Disease Research Trt# Company 16 Sandoz Rate per 1000 ft2 0.167 oz Product Sentinel 40 WG + Daconil Ultrex 82.5 WDG 3.8 oz Interval (days) 21 # of infection centers/plot 6/27 7/10 7/24 5.5 1.8 2.5 17 Sandoz Rizolex 75 WP 2.5 oz 14 43.8 32.3 65.5 18 Sandoz Sentinel 40 WG 0.167 oz 21 6.3 1.8 1.5 19 Sandoz Heritage 50 WDG 0.2 oz 14 22.5 8.8 47.5 20 Sandoz Banner 1.24 MEC 1 fl oz 14 3.8 1.8 1.5 21 Terra Thalonil 90 DF 3.5 oz 14 8.8 8.0 8.8 22 Terra Thalonil 4 L 6 fl oz 14 27.5 30.3 75.8 23 Terra TRA 0106 4 fl oz 14 14.3 6.5 27.5 24 Ciba Geigy CGA-BMP WP 0.56 oz 21 4.8 1.8 2.3 25 Ciba Geigy Banner Maxx 1 fl oz 21 9.5 7.8 1.3 26 Bayer Lynx 25 DF 1 oz 28 6.3 8.0 1.8 27 Bayer Lynx 250 EW 28.4 ml 28 5.3 3.0 2.5 28 Bayer Bayleton 25 DF 29 ISK Biotech Daconil Ultrex 1 oz 28 7.8 7.3 1.8 3.8 oz 14 16.3 8.3 11.5 30 ISK Biotech Daconil Weather Stik 4.1 fl oz 14 4.5 2.5 6.3 31 ISK Biotech Daconil Zn 6.0 fl oz 14 7.5 4.8 11.3 32 ISK Biotech IB 11522 4.0 oz 14 9.3 5.0 13.8 33 ISK Biotech IB 12231 4.7 oz 14 22.5 11.5 28.8 34 ISK Biotech Daconil Ultrex 3.8 oz 14 4.3 1.8 4.8 + Aliette 80 WDG 4.0 oz 14 35.0 37.5 28.8 14 5.0 5.3 1.3 14 11.3 2.3 1.8 14 3.0 4.0 3.3 14 4.0 1.3 1.3 14 13.0 2.8 58.8 14 13.8 9.3 75.0 35 ISK Biotech 36 ISK Biotech Daconil Zn 6.0 fl oz + Aliette 80 WDG 4.0 oz Daconil Ultrex 3.8 oz + IB 10813 0.5% v/v 2.0 fl oz 37 Rhone-Poulenc Chipco 26019 FLO + Banner 1.24 MEC 0.5 fl oz 38 Rhone-Poulenc Chipco 26019 FLO 2.0 fl oz + Bayleton 25 % DF 39 40 41 42 Rhone-Poulenc Rhone-Poulenc Rhone-Poulenc Rhone-Poulenc 0.5 oz Chipco 26019 FLO 2.0 fl oz + Cleary 3336 F 1.0 fl oz Chipco 26019 FLO 2.0 fl oz + Heritage 50 WG 0.2 oz Chipco 26019 FLO 2.0 fl oz + Daconil 2787 3.0 fl oz Chipco 26019 FLO 4.0 fl oz 14 11.5 3.8 12.8 412.2 373.6 1917.0 LSD3 28.1 26.8 1Sentinel + Daconil at first application date, Daconil alone at second application date, then repeat. 2Mean square error, df = 129. n = 4. 3Least significant difference. P < 0.05. 60.7 MSE2 I 52 Turfgrass Disease Research Evaluation of Fungicides for Control of Metalaxyl-resistant Pythium Blight on Creeping Bentgrass, 1994-1995 Michael W. Daly (Novartis Corporation), Nick E. Christians, and Mark L. Gleason The object of the trial was to evaluate the efficacy of various fungicide applications on turf that was typed resistant to metalaxyl in 1991. The trial was conducted on the fairway of hole #11 at Elmcrest Country Club, Cedar Rapids, Iowa. The fairway is composed of 80% “Penncross” creeping bentgrass ( Agrostispalustris) and 20% Poa annua, and has had severe outbreaks of pythium blight over the last 12 years. The fairway is a lightly modified native soil, the soil type is a Tama silty clay loam. Drainage is average to poor. Nutrient levels are average to high. The fairway is maintained at a height of 0.5 inches. The thatch level is less than 0.5 inches. From 1986 through 1990, the fairway received six Banol applications at 2 oz/1000 ft2, six applications of Aliette at 4 oz/1000 ft2, and eight applications of Subdue at 2 oz/1000 ft2. Rick Tegtmeier, course superintendent, noticed decreased intervals of control after the Subdue applications in 1990; from 14-21 days of control down to 7-14 days. Control of Pythium in 1990 required six fungicide applications due to the shortened control interval. The decision was made to switch to a tank mix of Subdue at 2 oz. and Mancozeb at 6 oz/1000 ft2 for 1991 to tiy and maximize control intervals. An application was made on 6/5/91 and breakthrough was noticed by 6/11. A sample of diseased turf was taken on 6/12/91 and sent to the Novartis research lab in Vero Beach, FL. The sample arrived on 6/13 in very good condition and one fast-growing Pythium was recovered and typed as Pythium aphanidermatum. A sensitivity test was done comparing this sample to a known sensitive P.Aphanidermatum control. The EC 50 of the sample to metalaxyl was greater than 100 ppm versus an EC 50 of 0.53 for the control. The sample was classified as resistant to Subdue. In 1994, the superintendent expressed an interest in finding out what his control options would be after three years of no Subdue applications. An experimental plot was designed using a randomized series of treatment strips down the fairway with the most pressure historically. The size of each strip was 7 fit x 100 ft (the width of the fairway), and the treatments were replicated four times. The applications were made with a “Grounds Wheelie” push sprayer with 2 gallons/1000 ft2 of carrier using flat fan nozzles. An application was made on 7/1/94 with a second application on 8/5/94. Cool weather during this time frame resulted in no disease pressure. The trial was continued in 1995 with an application made on 7/15. The temperature was 89° F with winds of 5-10 mph and full sun. Hot, humid weather developed subsequently and Pythium was noticed in the plots on 7/31. Data was taken on 8/1 by counting the number of disease centers in each plot by the superintendent and his assistant, Jeff Schmidt. A separate rating of the phytotoxicity to the turf by the various fungicide treatments was made at the same time when differences were noticed while counting the disease centers. The individuals doing the rating did not know which products had been applied to each plot. Results are compiled below. Mean number of disease Treatment____________ Rate/1000 ft2_____________ centers/treatment Subdue 2E 2 oz.............................................. 5.25 a Banol 2 oz.............................................. 5.13 a Untreated check .......................................................4.63 a Aliette 4 oz.............................................. 3.75 ab Subdue 2E + Banol 2 oz. +2 oz...................................3.00 ab Subdue + Mancozeb 2 oz. + 6 oz................................. 1.3 8 b Mean of 4 replications. Mean with the same letter are not significantly different. (LSD = 2.43, P=0.05) 53 Turfgrass Disease Research It is interesting that the best treatment was a tank mix that included Subdue. That tank mix has been included in the Pythium disease program during the summers of 1995 and 1996 and seems to be performing well, as the data would indicate. It would also be interesting to take a sample of disease off the fairways now and run the same sensitivity trial on it to see if there has been any change in the pathogen since 1991. More research is necessary to determine if these results would be applicable to any other sites with metalaxyl resistance. The results would seem to confirm the theory that tank mixes are an appropriate strategy in response to resistance concerns. Below is the data rating the damage to the turf from the various applications to the fairway. It should be noted again that the temperature was 89° F and sunny during the applications. The rating used was 10 for no phyto down to 1 for dead turf. The superintendent expected that Subdue 2E would cause the most damage due to the xylene inert (carrier) and was surprised that Aliette wettable powder actually caused the most phyto problem. Treatment___________ Rate 1000 ft2_________________ Rating Untreated check ....................................................9.75 a Subdue 2E + Band 2 oz. + 2 oz..................................9.50 ab B and 2 oz.............................................9.50 ab Subdue + Mancozeb 2 oz. + 6 oz..................................9.13 b Subdue2E 2 oz.............................................8.50 c Aliette __________ 4 oz.............. 7.88 d Mean of 4 replications. Mean with the same letter are not significantly different. (LSD=0.54, P=0.05) 54 Fertilizer Trials and Soil Studies Kentucky Bluegrass Fertilizer Study Barbara R. Bingaman, Nick E. Christians, and David S. Gardner The purpose of this study was to evaluate the response of Kentucky bluegrass to several turf fertilizer formulations. The experimental plot was an established area of ‘Park’ Kentucky bluegrass at the Iowa State University Horticulture Research Station north of Ames, Iowa. The soil in this area was a Nicollet (fine-loamy, mixed, mesic Aquic Hapludoll) with 3.5% organic matter, a pH of 7.3, 6 ppm P and 85 ppm K. Irrigation was used to supplement rainfall and maintain the turf in good growing condition. The experiment was arranged in a randomized complete block design. Individual plots were 5 x 5 ft and three replications were conducted. Three-foot barrier rows were placed between replications to facilitate taking clippings. Natural fertilizers and commercial mixtures were included in this study in single and split applications (Table 1). There were 11 treatments including eight different fertilizers and an untreated control. Two Turfgo fertilizer formulations from Viridian Inc. containing ESN #2003 mini coated material were used (23-5-10 and 22-5-10). They were applied at an annual rate of 4 lb N/1000 ft2 in split applications. Two Renaissance products from Renaissance Fertilizers Inc. were included. The 6-0-6 formulation was applied at a yearly rate of 4 lbs N/1000 ft2 in split applications. The 8-2-6 mixture was applied at 2 and 3 lbs N/1000 ft2 in single applications and at 4 lbs N/1000 ft2 in split applications. Com gluten meal from Grain Processing Inc., sustane (turkey manure), milorganite (processed sewage sludge), and Poly Plus sulfur coated urea (39-0-0) from LESCO Inc. also were included. They were applied at 4 lbs N/1000 ft2 in split applications. Prior to treatment the plot was mowed to a uniform height of 2 inches. A survey of the area was made before application and the bluegrass was found to be uniform in color and overall quality. The fertilizers were applied using plastic coated containers as ‘shaker dispensers’. Initial applications were made June 3. Sequential applications were made August 8. Fresh clipping weight and visual quality data was taken weekly beginning eight days after initial treatment. Turf quality was assessed using a 9 to 1 scale: 9 = best quality, 6 = lowest acceptable quality, and 1 = poorest quality (Tables 2 and 3). Clipping weights were measured as grams fresh tissue and mowing height for the clippings was 2 inches (Tables 4 and 5). Data were analyzed using the Statistical Analysis System (SAS) version 6.09 and the Analysis of Variance (ANOVA) procedure. Means comparisons were made with Fisher’s Least Significant Difference (LSD) test. There were significant differences in turf quality among the treatments on each of the 15 data collection dates. All fertilizers produced significantly higher quality bluegrass than the untreated controls from June 19 through September 12. During this period, the quality of all fertilized turf was above the lowest acceptable rating of ‘6’ (Tables 3 and 4). Renaissance at 3 lbs N/1000 ft2 consistently produced very good turf quality through August 8. Bluegrass treated with the two ESN #2003 products, com gluten meal, and Renaissance (6-0-6) also exhibited good quality through August 8. All bluegrass that received a sequential fertilizer treatment on August 8 had significantly higher quality than the untreated controls through October 3. Sulfur coated urea, the two ESN #2003 products, com gluten meal, Renaissance (8-2-6) in split applications, and Renaissance (6-0-6) produced the best quality bluegrass (Table 2 and 3). Turf quality declined after August 8 in those plots that did not receive sequential applications. 55 Fertilizer Trials and Soil Studies Mean turf quality for all fertilized bluegrass was significantly better than the untreated controls. The two ESN #2003 products, sulfur coated urea, com gluten meal and Renaissance (6-0-6) produced bluegrass with the best overall quality (Table 3). Fresh clipping weights from treated bluegrass were significantly different from the untreated control for 13 weeks of the 15-week study (Tables 4 and 5). Significant differences among the fertilizer treatments also were found on each of these dates. Growth response to most of the products was maintained from June 11 through August 8 as shown by the clipping weights. On August 15, the clipping weights reflect a rapid growth response to the sequential applications of some of the materials including the two ESN #2003 formulations, sulfur coated urea, and Renaissance (6-0-6). By August 23, all turf receiving a sequential application exhibited substantial clipping increases as compared with the untreated controls and those not treated on August 8 (Table 3 and 4). This trend continued through the late summer and early fall. Mean and total clipping weights for all of the fertilizers were significantly higher than the untreated controls (Table 5). ESN #2003 (22-5-10) produced the most clippings followed by ESN #2003 (235-10), sulfur coated urea, corn gluten meal, Renaissance (8-2-6) (treatment 7), and Renaissance (6-06). Table 1. Rates and number of applications for fertilizer formulations used in the 1996 Kentucky Bluegrass Fertilizer Trial. Materials1 Yearly lbs N/1000 ft2 Initial application lbs N/1000 ft2 Sequential application lbs N/1000 ft2 NA NA NA 1. Untreated control 2. Com gluten meal (10% N) 4 2 2 3. Sustane (5-2-4) 4 2 2 4. Renaissance (6-0-6) 4 2 2 5. Renaissance (8-2-6) 2 2 0 6. Renaissance (8-2-6) 3 3 0 7. Renaissance (8-2-6) 4 2 2 8. Milorganite (6-2-0) 4 2 2 9. ESN #2003 (23-5-10) 4 2 2 10. ESN #2003 (22-5-10) 4 2 2 11. Sulfur coated urea(3 9-0-0) 2 2 4 (LESCO Poly Plus™) 1 -r 1 Initial applications were made on June 3 and sequential on August 8. 56 Fertilizer Trials and Soil Studies Table 2. Visual quality1of Kentucky bluegrass treated with fertilizer materials in the 1996 Kentucky Bluegrass Fertilizer Trial (data through August 15). June Rate3 lbs N/1000 ft2 11 NA 6 June 19 5 June 25 5 July 2 5 July 12 6 July 23 6 July 30 6 Aug 8 6 Aug 15 6 1. Materials2 Untreated control 2. Com gluten meal (10% N) 4-split 6 7 9 8 8 8 8 8 8 3. Sustane (5-2-4) 4-split 7 7 7 6 7 7 7 7 8 4. Renaissance (6-0-6) 4-split 7 9 8 7 7 8 8 8 9 5. Renaissance (8-2-6) 2 7 8 8 7 7 8 8 8 6 6. Renaissance (8-2-6) 3 7 9 9 9 9 9 9 9 7 7. Renaissance (8-2-6) 4-split 7 7 8 7 7 8 8 7 8 8. Milorganite (6-2-0) 4-split 7 7 7 6 7 7 7 7 8 9. ESN #2003 (23-5-10) 4-split 8 8 8 7 8 8 8 8 9 10. ESN #2003 (22-5-10) 4-split 9 9 8 8 8 9 8 8 9 11. Sulfur coated urea (39-0-0) 4-split 8 8 7 7 7 7 7 7 9 1 1 1 1 1 1 1 1 1 L S D oos 1 Visual quality was assessed using a 9 to 1 scale: 9 = best quality, 6 = lowest acceptable quality, and 1 = poorest quality. 2 Initial applications were made on June 3 and sequential on August 8. 3 Treatments 5 and 6 received only 1 application of fertilizer, the other treatments were made in split applications of 2 lbs. Table 3. Visual quality1of Kentucky bluegrass treated with fertilizer materials in the 1996 Kentucky Bluegrass Fertilizer Trial (data from August 23 through October 3)._____________________________________________ Rate3 lbs N/1000 ft2 NA Aug 23 6 Aug 29 6 Sept 5 5 Sept 12 5 Sept 19 5 Oct 3 5 Mean quality 6 1 Materials2 Untreated control 2. Com gluten meal (10% N) 4-split 9 9 9 8 7 8 8 3. Sustane (5-2-4) 4-split 9 8 7 7 7 7 7 4. Renaissance (6-0-6) 4-split 9 8 8 7 7 7 8 5. Renaissance (8-2-6) 2 7 7 6 6 6 6 7 6. Renaissance (8-2-6) 3 7 7 6 6 5 5 8 7. Renaissance (8-2-6) 4-split 9 9 8 8 7 7 8 8. Milorganite (6-2-0) 4-split 8 8 8 7 7 7 7 9. ESN #2003 (23-5-10) 4-split 9 9 9 8 7 8 8 10. ESN #2003 (22-5-10) 4-split 9 9 9 9 8 9 8 11. Sulfur coated urea (39-0-0) 4-split 9 9 9 9 8 9 8 . 1 1 1 1 1 1 0.3 L S D o os 1 Visual quality was assessed using a 9 to 1 scale: 9 = best quality, 6 = lowest acceptable quality, and 1 = poorest quality. 2 Initial applications were made on June 3 and sequential on August 8. 3 Treatments 5 and 6 received only 1 application of fertilizer, the other treatments were made in split applications of 2 lbs. 1 T 7• 57 Fertilizer Trials and Soil Studies Table 4. Clipping weights1of Kentucky bluegrass treated with fertilizer materials in the 1996 Kentucky Bluegrass 1. Fertilizer Trial (data from June 11 through August 23). Rate3 lbs N/ June June June 25 1000 ft2 11 19 Materials2 NA 171 105 102 Untreated control 2. Com gluten meal (10% N) 4-split 184 172 203 107 94 198 146 157 163 305 3. Sustane (5-2-4) 4-split 199 180 155 68 56 121 109 112 134 239 4. Renaissance (6-0-6) 4-split 206 263 207 88 75 170 130 128 172 348 5. Renaissance (8-2-6) 2 236 223 209 108 81 188 140 154 114 118 6. Renaissance (8-2-6) 3 183 238 261 110 93 260 179 166 135 133 7. Renaissance (8-2-6) 4-split 207 198 183 94 66 152 126 128 155 292 8. Milorganite (6-2-0) 4-split 223 196 152 80 71 140 114 133 142 246 9. ESN #2003 (23-5-10) 4-split 241 302 197 94 84 211 144 153 233 377 10. ESN #2003 (22-5-10) 4-split 279 303 204 86 101 224 151 150 235 415 11. Sulfur coated urea (39-0-0) 4-split 267 273 138 78 73 161 124 135 188 360 July 2 69 July 12 40 July 23 66 July 30 63 Aug 8 65 Aug 15 61 Aug 23 72 59 NS 51 NS 17 30 18 32 24 40 L S D oos 1Clipping weights are expressed as grams fresh weight. 2 Initial applications were made on June 3 and sequential on August 8. 3Treatments 5 and 6 received only 1 application of fertilizer, the other treatments were made in split applications of 2 lbs. NS = means are not significantly different at the 0.05 level. Table 5. Clipping weights1of Kentucky bluegrass treated with fertilizer materials in the 1996 Kentucky Bluegrass 1. Fertilizer Trial (data from August 29 through October 3). Rate3 Sept lbs Aug Materials2 N/1000 ft2 29 5 NA 48 46 Untreated control 2. Com gluten meal (10% N) 4-split 187 153 120 63 72 155 2325 3. Sustane (5-2-4) 4-split 126 108 85 46 49 119 1786 4. Renaissance (6-0-6) 4-split 173 137 101 50 57 154 2304 5. Renaissance (8-2-6) 2 73 77 66 35 42 124 1864 6. Renaissance (8-2-6) 3 76 82 73 47 41 138 2076 7. Renaissance (8-2-6) 4-split 167 152 118 55 62 144 2154 8. Milorganite (6-2-0) 4-split 135 123 92 54 58 131 1959 9. ESN #2003 (23-5-10) 4-split 182 166 130 69 83 178 2666 10. ESN #2003 (22-5-10) 4-split 201 170 145 71 83 188 2818 11. Sulfur coated urea (39-0-0) 4-split 184 166 136 71 87 163 2438 Sept 12 48 Sept 19 25 Oct 3 24 Mean weight 67 Total clipping weight 1003 14 20 23 9 8 16 247 L S D oos 1Clipping weights are expressed as grams fresh weight. 2 Initial applications were made on June 3 and sequential on August 8. J Treatments 5 and 6 received only 1 application of fertilizer, the other treatments were made in split applications of 2 lbs. NS = means are not significantly different at the 0.05 level. 58 Fertilizer Trials and Soil Studies Vigoro Kentucky Bluegrass Fertilizer Study - 1996 Barbara R. Bingaman, Nick E. Christians, and David S. Gardner The purpose of this study was to screen two fertilizer products from Vigoro for longevity and safety on Kentucky bluegrass. The study was conducted at the Iowa State University Horticulture Research Station north of Ames, Iowa. The experimental area was ‘Park’ Kentucky bluegrass that was not fertilized this spring. The soil in this plot was a Nicollet (fine-loamy, mixed, mesic Aquic Hapludoll) with 3.5% organic matter, a pH of 7.3, 6 ppm P, and 85 ppm K. The experiment was designed as a randomized complete block with three replications. Individual plots were 5 x 5 ft with 3 ft barrier strips between replications. There were four fertilizer treatments plus an untreated control. ParEx (24-4-12) and Experimental (21-4-12) were applied at 0.5 and 1.0 lb N/1000 ft2 in single applications (Table 1). In addition, ParEx and Experimental were applied at 2.0 lb N/1000 ft2 to nonreplicated 5 x 5 ft plots to evaluate the potential for fertilizer bum. Applications were made June 13, 1996 using plastic coated containers as ‘shaker dispensers’. A pre­ treatment survey of the plot confirmed that turf quality was uniform. Irrigation was used to ‘water in’ the materials. Visual quality and fresh clipping weight data were taken weekly beginning June 19. Subsequent data were taken on June 19, June 24, July 2, July 12, July 23, July 30, August 8, August 15, and August 23. Visual quality data also were taken on these days for the two nonreplicated demonstration plots. In some cases, slow turf growth and weather conditions necessitated changes in the collection dates. Turf quality was assessed with visual ratings using a 9 to 1 scale: 9 = best quality, 6 = lowest acceptable quality, and 1 = poorest quality (Table 1). Clipping weights were recorded in grams fresh weight and the mowing height for collecting clippings was 2 inches (Table 2). The nonreplicated plots were mowed at the same height but clippings were not collected. The plot was surveyed for phytotoxicity throughout the duration. Data were analyzed using the Statistical Analysis System (SAS) version 6.09 and the Analysis of Variance (ANOVA) procedure. Means comparisons were made using Fisher’s Least Significant Difference test (LSD). The quality data from the nonreplicated demonstration plots were not included in the analyses. Among the replicated plots, there were significant quality differences on June 19 and August 8. The higher rates of ParEx and Experimental produced the best quality when compared with the other treatments and untreated controls. Turf quality was consistently better for the bluegrass treated with ParEx and Experimental at 2.0 lb N/1000 ft2 than for the other treated and untreated turf. By August 23, the fertilizer effects were gone and turf quality was uniform among all treated and untreated turf (Table 1). No phytotoxicity was detected on the fertilized plots throughout the duration of the test. The nonreplicated, demonstration plots treated at 2 lb N/1000 ft2 also were monitored and there were no bum symptoms on these plots. Clipping weights were significantly higher for all treated bluegrass when compared with the untreated controls on July 2, July 12, and July 23. 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' S ; ~C O h VO X ON .g . iCN l S T3 ^ C/3 c/3 O ^ C ^ o ° <£5 — § 2 ° - ^ On Ë — < z ^ (N (N cd oo ^r •4-» cd o <3 bO CD d o d '»-* cCD fi o fo £ T3 c £ c) C2 ST3 o o 4-> NO ^E *3 C/3 NO h-> CD d O c/3 ^ cd -*-» 5 g O ^ © £ CD ' • cd ° 9A -o © ° o d o cd -4-» CO [3 (D -4—» cd ^ £ CO ) — 3 cd opo cd °o "4-> cd N (D Cd i s •C d a> .op ^ '2 bn o © CD ~ >vS ^ *2 +T3 ^ ^ > JÉ § Cd O OO c < _ - ^ O d c *s iH a 3 vo D cd C/3 C/3 o oo vo c D TCD3 cd •+ -* NO CD C2 cCD ON in r- oo C/3 o Oh m rNO Oh z E d d o CO o OO CN 3 c2 CD Oh d O m _o 3 d a Œ C/3 (N 'rt o d o -O 2 £ m Oh c ^ C/3 o S o CD -C CO CD cn E $-h o 5o Ph E ON C/3 o o t—H d C/3 On CD m 00 o oo oo o c/3 cd z VO ¿2 ^ Ë a o C CD r- e S d Hc « ^ H O o o c CZ5 cd cd o o CD T3 D CD -4-» cd 59% in all com gluten meal-treated turf except at 20 lbs /1000 ft2. At this CGM level, there were more crabgrass plants than in the untreated controls. Reductions were 97, 79, 59, 83, and 97% for 40, 60, 80, 100, and 120 lbs/1000 ft2 CGM, respectively. Crabgrass control data for 1991-1995 were compared with data from 1996 (Table 5). Percentage reductions in 1996 were generally higher than those recorded in 1995. 67 Environmental Research There were significant reductions in the percentage of broadleaf weed cover in the treated as compared with the untreated bluegrass plots (Table 3). Percent cover was significantly lower in all CGM treated plots as compared to the untreated controls. Percentage of clover cover was significantly reduced by all CGM levels (Table 4). Mean percent cover data also indicated large reductions in treated versus untreated control turf. Reductions in percent clover cover from 1996 were similar to those from 1994 at 20, 40, 60, 80, 100, and 120 lbs/1000 ft2 and larger than those reported for 1995 at 20, 40, 80, and 100 lbs/1000 ft2 (Table 6). The number of dandelions was significantly reduced by all CGM levels except 20 lbs/1000 ft2 (Table 5). In 1994, dandelion was controlled better than in 1995 and 1996 at 20, 40, and 60 lbs/1000 ft2 (Table 6). Reductions were similar for all three years at 80,100, and 120 lbs/1000 ft2. Table 1. Visual quality1 of Kentucky bluegrass treated with granular com gluten meal in the 1991 Com Gluten Meal Weed Control Study. Material 1. Untreated control lbs CGM /1000ft2 lbsN /1000 ft2 June 7 July 10 July 30 Aug 23 Mean quality 0 0 6 7 7 7 7 2. Com gluten meal 20 2 7 7 7 7 7 3. Com gluten meal 40 4 8 8 8 8 8 4. Com gluten meal 60 6 9 8 8 8 8 5. Com gluten meal 80 8 9 9 8 8 - 9 6. Com gluten meal 100 10 9 9 9 9 9 7. Com gluten meal 120 12 9 9 9 9 9 1 1 1 1 1 LSDo.os 1 Visual quality was assessed using a 9 to 1 scale: 9 = best quality, 6 = lowest acceptable quality, and 1 = poorest quality. Table 2. Number of crabgrass plants1 in Kentucky bluegrass plots treated with granular com gluten meal for the 1991 Com Gluten Meal Weed Control Study. Material lbs CGM /1000 ft2 lbs N /1000 ft2 August 23 % Reduction in Numbers2 1. Untreated control 0 0 13 0 2. Com gluten meal 20 2 11 15 3. Com gluten meal 40 4 1 97 4. Com gluten meal 60 6 2 85 5. Com gluten meal 80 8 4 69 6. Com gluten meal 100 10 2 87 7. Com gluten meal 120 12 1 97 8 60 LSDo.os 1 These values represent the actual number of crabgrass plants per plot. 2 These values represent the percentage reductions in crabgrass plants per plot as compared with the untreated controls. 68 Environmental Research Table 3. Percentage of broadleaf cover1 in Kentucky bluegrass treated with granular com gluten meal in ________ the 1991 Com Gluten Meal Weed Control Study.___________________________________ Material lbsN /1000 ft2 June 7 July 10 July 30 Mean % cover Percent reduction2 1. Untreated control 0 43 53 58 52 0 2. Com gluten meal 2 23 23 28 25 52 3. Com gluten meal 4 10 7 10 9 83 4. Com gluten meal 6 4 2 4 3 94 5. Com gluten meal 8 4 1 7 4 93 6. Com gluten meal 10 4 4 7 5 91 7. Com gluten meal 12 1 4 4 3 95 18 10 13 10 20 LSD0.05 1 Dandelion and clover were the only broadleaf species detected in the plots. These percentages represent the amount of area per plot covered by dandelion and clover. 2 These values represent the percentage reductions in crabgrass plants per plot as compared with the untreated controls. Table 4. Percentage clover cover1 and dandelion counts per plot2 in Kentucky bluegrass treated with in ________ the 1991 Com Gluten Meal Weed Control Study.____________________________________ Percentage clover cover (%)1 Material lbsN /1000 ft2 May 9 August 23 1 Untreated control 0 15 27 2 Com gluten meal 2 7 3 Com gluten meal 4 4 Com gluten meal 5 Mean % cover Dandelion counts per plot2 May 9 August 23 Mean number 21 19 20 19 5 6 10 16 13 5 2 4 4 5 5 6 1 2 2 2 6 4 Com gluten meal 8 4 1 2 1 1 1 6 Com gluten meal 10 2 1 2 0 1 1 7 Com gluten meal 12 1 2 2 0 0 0 7 14 6 12 11 11 LSD(o.os) ‘Percentage clover cover represents the area per plot covered by clover. 2Dandelion counts are the actual number of dandelion per plot. 69 Environmental Research Table 5. Comparisons of the percentage crabgrass reductions1 in Kentucky bluegrass treated with ________ granular com gluten meal in the 1991 Com Gluten Meal Weed Control Study through 1996. Percent crabgrass reduction (%) Material lbsN/1000 ft2 1991 1992 1993 1994 1995 1996 1 Untreated control 0 0 0 0 0 0 0 2 Com gluten meal 2 58 85 91 70 36 15 3 Com gluten meal 4 86 98 98 97 88 97 4 Com gluten meal 6 97 98 93 98 93 85 5 Com gluten meal 8 87 93 93 87 75 69 6 Com gluten meal 10 79 94 95 86 75 87 7 Com gluten meal 12 97 100 100 98 84 97 26 44 31 39 40 60 LSDq.05 1These values represent the percentage reductions in crabgrass plants per plot as compared with the untreated controls. Table 6. Reductions in percentages clover cover1 and number of dandelions per plot2 for 1994-1996 in Kentucky bluegrass treated with com gluten meal in the 1991 Com Gluten Meal Weed Control ________ Study.________________________________________________________________________ Percentage clover cover reduction3 Material lbsN/1000 ft2 1994 1995 Reduction in dandelion numbers3 1996 1994 1995 1996 1 Untreated control 0 0 0 0 0 0 0 2 Com gluten meal 2 81 56 71 71 49 33 3 Com gluten meal 4 90 64 82 100 77 75 4 Com gluten meal 6 98 93 93 100 89 79 5 Com gluten meal 8 100 76 90 98 96 95 6 Com gluten meal 10 94 84 92 100 98 96 7 Com gluten meal 12 90 93 93 100 100 100 NS 48 29 50 65 60 LSD(o.o5) 1 Percentage clover cover represent the area per plot covered by clover. 2 Dandelion counts are the actual number of dandelions per plot. 3 These values represent the percentage reductions in plants per plot as compared with the untreated controls. NS = not significantly different at the 0.05 level. 70 Environmental Research 1995 Corn Gluten Meal Rate Weed Control Study - Year 2 Barbara R. Bingaman and Nick E. Christians Com gluten meal (CGM) was screened for efficacy as a natural product herbicide in turf. This trial is a long-term study started in 1995 that will be continued on the same area for several years. It is being conducted at the Iowa State University Horticulture Research Station north of Ames, Iowa. The experiment is located in an area of'Ram T Kentucky bluegrass. The soil in this area is a Nicollet (fineloamy, mixed, mesic Aquic Hapludoll) with an organic matter content of 3.7%, a pH of 7.1,4 ppm P, and 100 ppm K. The initial broadleaf weed population exceeded 50% cover on most of the test area. Individual experimental plots are 10 x 10 ft and there are five treatments with three replications. The experimental design is a randomized complete block. Com gluten meal was applied at a yearly rate of 40 lb CGM/1000 fit2 (equivalent to 4 lb N/1000 ft2) using four different regimes of single and split applications (Table 1). Four applications of 10 lb/1000 ft2, split applications of 20 lb/1000 ft2, an initial application of 30 lbs plus a sequential of 10 lb/1000 ft2, and a single application of 40 lb/1000 ft2 were included with an untreated control. Initial applications were made April 24. The second application for treatment 2 was made May 28. On August 8, the third application of treatment 2, and the sequential applications of treatments 3 and 4 were made. The final application for treatment 2 was made September 5. The experimental plot was checked for phytotoxicity after applications. Visual quality data were taken May 22, June 10, June 26, July 10, July 30, August 23, and September 5. Visual quality was measured using a 9 to 1 scale: 9 = best quality, 6 = lowest acceptable quality, and 1 = poorest quality (Table 1). Crabgrass control was assessed counting the number of crabgrass plants per individual plot. Crabgrass control data were taken August 23 (Table 2). The first broadleaf control data for this study were taken in the spring of 1996. Broadleaf weed control was assessed by estimating the percentage of area in each plot covered by dandelion and clover. These data were taken June 10, June 26, July 10, and July 30 (Table 3). In addition, the percent cover of dandelion and clover were determined separately May 9, August 23, and September 5 (Tables 4 and 5). Data were analyzed with the Statistical Analysis System version 6.10 (SAS Institute, 1989) using the Analysis of Variance (ANOVA) procedure. Fisher’s Least Significant Difference test (LSD) was used to compare means. There were no phytotoxic symptoms detected on the treated bluegrass. Visual turf quality was better in bluegrass treated with CGM than in the untreated controls for the entire season (Table 1). Broadleaf weed species were well established when the crabgrass was emerging especially in the untreated controls. Competition from the broadleaves and the mature turf probably prevented the establishment of large crabgrass populations within the untreated plots. Consequently crabgrass numbers were quite low in all of the plots and when crabgrass data were taken August 23, the plants were still quite small with only two or three tillers. Com gluten meal did not significantly reduce the number of crabgrass plants per plot (Table 2). 71 Environmental Research In 1996, there were fewer crabgrass plants in turf treated with CGM in split applications at 20 lb CGM and at 30 lb followed by 10 lb CGM/1000 ft2 (treatments 3 and 4) than in the untreated controls (Table 2). In turf receiving the other CGM treatments, there were more crabgrass plants than in the untreated controls. Crabgrass numbers were much higher in 1995 than in 1996 and all CGM treatments reduced crabgrass numbers when compared with the untreated controls. In 1996, crabgrass control was better in turf receiving 30 lb followed by 10 lb CGM/1000 ft2 than in 1995. Percent broadleaf cover was significantly reduced by com gluten meal throughout the season (Table 3). The best broadleaf control was provided at 40 lb CGM/1000 ft2 in a single, spring application but this level was not different from the other CGM rates. Dandelion and clover cover were reduced in turf treated with CGM but the reductions were not significantly different than the untreated controls (Table 4 and 5). Treatment at all CGM rates except the split application of 30 lb followed by 10 lb CGM/1000 ft2 (treatment 4) resulted in 50% dandelion cover reductions (Table 4). Reduction in percentage cover was 28% in turf treated with 30 lb followed by 10 lb CGM/1000 ft2. The best clover control was in turf treated with 3 lb followed by 10 lb CGM/1000 ft2 and with 40 lb/1000 ft2 in a single application (Table 5). Table 1. Visual quality1of Kentucky bluegrass treated with com gluten meal in the 1995 Com Gluten Meal Rate Weed Control Study. May June June 22 10 26 July 10 July 30 6 5 7 6 6 6 6 6 4 sequential 8 8 8 8 7 8 9 8 20 fb 20 split 8 8 8 7 8 9 9 8 Com gluten meal 30 fb 10 30 + 10 lb split 9 8 8 8 7 8 8 8 Com gluten meal 40 1 single 9 8 9 9 8 8 8 8 1 1 NS 1 1 1 1 1 Material CGM treatments (lb/1000 ft2) Application timing2 1. Untreated control 0 NA 2. Com gluten meal 10 fb 10 fb 10 fb 10 3. Com gluten meal 4. 5. L SD oos Aug Sept 5 23 Mean quality 1Visual quality was assessed using a 9 to 1 scale: 9 = best quality, 6 = lowest acceptable quality, and 1 = poorest quality. 2 All treatments were at an annual rate of 4 lbs N/1000 fit2. Initial applications were made on April 24; 2nd application of trt 2 on May 28; 3rd application of trt 2 and 2nd of trt 3 & 4 on August 8; and final application o f trt 2 on September 5. NS = means are not significantly different at the 0.05 level 72 Environmental Research Table 2. Crabgrass counts per plot1 and crabgrass reductions2 in Kentucky bluegrass treated with com Crabgrass counts1 Material 1. Untreated control Application timing3 Percent crabgrass reduction2 August 23 1995 1996 NA 4 0 0 2. Com gluten meal sequential 7 28 0 3. Com gluten meal split 3 45 33 4. Com gluten meal split 1 44 67 5. Com gluten meal single 5 54 0 NS NS NS LSDq.05 These data represent the number of crabgrass plants per plot. 2 These values represent the percentage reductions in plants per plot as compared with the untreated controls. 3 All treatments were at an annual rate of 4 lbs N/1000 ft2. Initial applications were made on April 24; 2nd application of trt 2 on May 28; 3rd application of trt 2 and 2nd of trt 3 & 4 on August 8; and final application of trt 2 on September 5. NS = means are not significantly different at the 0.05 level. Table 3. Percent broadleaf cover1 in Kentucky bluegrass treated with com gluten meal for the 1995 Com Material 1. Untreated control Application timing2 June 10 June 26 July 10 July 30 Mean % cover % cover reduction3 NA 58 40 50 62 53 0 2. Com gluten meal sequential 20 25 23 27 24 55 3. Com gluten meal split 20 15 20 20 19 65 4. Com gluten meal split 17 15 23 22 19 64 5. Com gluten meal single 13 15 22 18 17 68 18 13 20 13 14 26 LSDo.oj 2A11 treatments were at an annual rate of 4 lbs N/1000 ft2. Initial applications were made on April 24; 2nd application of trt 2 on May 28; 3rd application of trt 2 and 2nd of trt 3 & 4 on August 8; and final application of trt 2 on September 5. 3These values represent the percentage reductions in plants per plot as compared with the untreated controls. 73 Environmental Research Table 4. Percentage dandelion cover1 in Kentucky bluegrass treated with com gluten meal in the 1995 Com Gluten Meal Rate Weed Control Study. Material 1. Untreated control Application timing2 August 23 May 9 September 5 Mean % cover % Cover reduction NA 20 27 23 23 0 2. Com gluten meal sequential 10 15 12 12 48 3. Com gluten meal split 13 10 12 12 50 4. Com gluten meal split 15 15 20 17 28 5. Com gluten meal single 13 10 12 12 50 NS NS NS NS NS LSD005 1Percentage cover represents the amount of area per plot covered by dandelion. 2 Initial applications were made on April 24; 2nd application of trt 2 on May 28; 3rd application of trt 2 and 2nd of trt 3 & 4 on August 8; and final application of trt 2 on September 5. NS = means are not significantly different at the 0.05 level. Table 5. Percent clover cover1 in Kentucky bluegrass treated with com gluten meal in the 1995 Com Material 1. Untreated control Application timing2 May 9 August 23 September 5 Mean % cover % Cover reduction NA 12 22 27 20 0 2. Com gluten meal sequential 8 12 13 11 45 3. Com gluten meal split 5 7 7 6 69 4. Com gluten meal split 2 4 1 3 90 5. Com gluten meal single 2 1 2 2 92 NS NS NS NS NS LSDo.os “TTT“ Percentage cover represents the amount of area per plot covered by dandelion. 2 All treatments were at an annual rate of 4 lbs N/1000 ft2. Initial applications were made on April 24; 2nd application of trt 2 on May 28; 3rd application of trt 2 and 2nd of trt 3 & 4 on August 8; and final application of trt 2 on September 5. NS = means are not significantly different at the 0.05 level. 74 Environmental Research 1995 Corn Gluten Hydrolysate Weed Control Study - Year 2 Barbara R. Bingaman and Nick E. Christians Com gluten hydrolysate (CGH) was screened for efficacy as a natural herbicide in turf. This trial is a long-term study started in 1995 that will be continued in the same experimental area for several years. It is being conducted at the Iowa State University Horticulture Research Station north of Ames, Iowa. The experiment is located in an area of'Ram T Kentucky bluegrass. The soil in this experimental area is a Nicollet (fine-loamy, mixed, mesic Aquic Hapludoll) with an organic matter content of 3.7% a pH of 7.1, 4 ppm P, and 100 ppm K. The experimental design is a randomized complete block with three replications. Individual experimental plots are 5 x 5 ft with 3 ft barrier rows between replications. Com gluten hydrolysate was applied at 5, 10, 15, and 20 lbs product/1000 ft2(Table 1). These rates are equivalent to 0.5, 1.0, 1.5, and 2.0 lbs N/1000 ft2 as CGH contains 10% N. The CGH was dissolved in water and the volumes applied were 700, 1400, 2100, and 2800 ml for the 5, 10, 15, and 20 lb rates, respectively. An untreated control was included for comparisons. The CGH was applied using a carbon dioxide backpack sprayer equipped with #8006 nozzles at 20 psi. All treated plots received a single application on May 14. Supplemental irrigation was used to provide adequate moisture to maintain the grass in good growing condition. Visual quality data were taken May 22 and June 10. Visual quality was measured using a 9 to 1 scale: 9 = best quality, 6 = lowest acceptable quality, and 1 = poorest quality (Table 1). Data for individual weed species were not taken because weed populations were very high especially in the untreated controls. The cool, wet spring delayed crabgrass germination until the broadleaf weed species (i.e. dandelion and clover) were well established. Weed control was assessed by making visual estimations of the percent of area per plot covered by broadleaf and grass weed species (Table 2). Representative species included dandelion, clover, black medic, and spurge. Weed control data were taken May 22, June 10, July 10, July 30, and August 23. Data were analyzed with the Statistical Analysis System version 6.10 (SAS Institute, 1989) using the Analysis of Variance (ANOVA) procedure. Fisher’s Least Significant Difference (LSD) means comparison tests were used to assess CGH effects on bluegrass quality and weed control. No phytotoxic symptoms were detected in any of the treated plots. Turf quality was improved by CGH as compared with the untreated control plots through June 10. After this date, there were no quality differences among the plots (Table 1). Weed populations were not significantly reduced by CGH (Table 2). On some of the data collection dates, percentage weed cover was higher in bluegrass treated with CGH than in the untreated controls. The majority of the weed cover consisted of dandelion and clover with only small sporadic populations of black medic and spurge. The absence of crabgrass could possibly be explained by the competition at the time of germination from dense populations of dandelion and clover. 75 Environmental Research Table 1. Visual quality1 of Kentucky bluegrass treated with com gluten hydrolysate for the 1995 Com Material lbs product /1000 ft2 May 22 June 10 Mean Quality 1. Untreated control NA 6 5 6 2. Com gluten hydrolysate 5 7 6 7 3. Com gluten hydrolysate 10 8 7 8 4. Com gluten hydrolysate 15 8 8 8 5. Com gluten hydrolysate 20 9 8 8 1 1 1 LSDo.os quality. Com gluten hydrolysate was applied on May 14, 1996. Table 2. Percentage of weed cover1 in Kentucky bluegrass treated with com gluten hydrolysate for the 1995 Com Gluten Hydrolysate Weed Control Study. Material lbs product /1000ft2 May 22 June 10 July 10 July 30 Aug 23 Mean % cover NA 53 47 60 58 67 57 Percent cover reduction 1. Untreated control 2. Com gluten hydrolysate 5 63 55 65 55 65 61 0 3. Com gluten hydrolysate 10 60 53 72 58 65 62 0 4. Com gluten hydrolysate 15 53 47 45 40 55 48 16 5. Com gluten hydrolysate 20 53 47 65 55 60 56 2 LSDo.os NS NS NS NS NS NS NS NS Percent cover is the percentage of area per plot covered by all broadleaf and grass weed species. Com gluten hydrolysate was applied on May 14, 1996. NS = not significantly different at the 0.05 level. 76 Environmental Research Pendimethalin and Corn Gluten Meal Combinations for Weed Control in Turfgrass David S. Gardner, Nick E. Christians, and Barbara R. Bingaman These field experiments were conducted at the Iowa State University Horticulture Research Station in an area of common Kentucky bluegrass {Poa pratensis L.) that had been established in 1968. The soil was a Nicollet with a pH of 6.2, 6.5 mg P kg'1, 77 mg K kg'1, and 22 g kg' 1 of organic matter. Twenty treatments consisting of four rates of com gluten meal combined in a factorial arrangement with five rates of pendimethalin 60 DG were applied individually to 20 plots. Each plot was 5 x 5 ft, and plots were arranged in a randomized complete block design with two rows of ten plots per block and 2.5 ft barrier rows between each of the three blocks. Powdered com gluten meal was hand-applied on 13 April 1995 and 24 April 1996, at single application rates of 0, 49, 98, or 147 g m'2. A carbon dioxide backpack sprayer, with a pressure of 30 psi using 8006 nozzles, was used to apply pendimethalin on 25 April 1995 and 1 May 1996 at single application rates of 0, 29, 59, 88 , or 117 mg ai m'2. The rates of pendimethalin tested were 1/6, 1/3, 1/2, and 2/3 of the minimum recommended application rate, and the rates of com gluten meal tested were 1/2, 1, and 2 times the recommended application rate of com gluten meal. The test plots were mowed and supplemental irrigation was used as necessary throughout the summer so that the turfgrass did not go dormant. No other fertilizer was applied during the study. In both years, data were collected as average visual estimates of two researchers as combined percentage cover of smooth crabgrass and large crabgrass 15 weeks after application of com gluten meal. Estimates of turfgrass visual quality were made 5, 7, 11, and 15 weeks after application of com gluten meal. Turfgrass visual quality was evaluated on a 9 to 1 scale: 9 = best quality, 6 = acceptable quality, and 1 = poorest quality based on overall color, density, and uniformity. Data were analyzed by using the Statistical Analysis System (SAS) and the general linear models (GLM) procedure. Data collected from the two years of field data were pooled. Fisher's least significant difference (LSD) test was used to compare main effect means and means over all treatments. The analysis showed differences among studies at the P0 05 level between years and replications. An additive effect on crabgrass cover was observed when com gluten meal and pendimethalin were applied in combination to turfgrass in the field. Each 49 g m'2 increase in applied com gluten meal reduced crabgrass cover but the level of reduction over the previous rate decreased as rate increased (Table 1). Analysis of the main effects showed that there was no increase in crabgrass control at rates higher than 59 mg ai m'2 pendimethalin. The application of 49 g m'2 com gluten meal and 88 mg ai m'2 pendimethalin provided 75-85% control as did either 98 g m'2 com gluten meal and 59 mg ai m'2 pendimethalin or 147 g m'2 com gluten meal and 29 mg ai m'2 pendimethalin. There was no increase in crabgrass control in plots that received larger amounts of com gluten meal and pendimethalin. Crabgrass reduction in plots that received 49 g m'2 com gluten meal and 59 mg ai m'2 pendimethalin were not different from the plots 77 Environmental Research that received 49 g m'2 com gluten meal and 88 mg ai m'2 pendimethalin. However, they were different from the plots that received 98 g m'2 com gluten meal and 59 mg ai m'2 pendimethalin. For each increase of 49 g m'2 com gluten meal, turfgrass visual quality was improved by approximately one unit on the 9 to 1 scale after 5 and 7 weeks (Table 2). The fertilizer effects of com gluten meal application were visible for 11 weeks. After 11 weeks, turfgrass quality did not differ among plots that received different rates of com gluten meal. Pendimethalin did not affect turfgrass visual quality. The results the field experiments suggest that crabgrass control may be improved by applying a sublethal rate of pendimethalin in combination with com gluten meal. Crabgrass control was improved over that of com gluten meal applied alone by using the three combinations of com gluten meal and pendimethalin. There was no difference in crabgrass control among these rate combinations (Table 1). The previously documented fertilizer effect caused by com gluten meal (Christians, 1993) was also observed in our field experiment. Increased turfgrass vigor caused by the fertilizer effect may contribute to the reduction in crabgrass observed on plots treated with com gluten meal (Christians, 1993). References Appleby, A.P. and B.E. Valverde. 1989. Behavior of dinitroaniline herbicides in plants. Weed Technol. 3:198-206. Bingaman, B.R. and N.E. Christians. 1995. Greenhouse screening of com gluten meal as a natural weed control product for broadleaf and grass weeds. HortScience 30:1256-1259. Christians, N.E. 1991. Preemergence weed control using com gluten meal. U.S. Patent No. 5,030,268. Date issued: 9 July. Christians, N.E. 1993. The use of corn gluten meal as a natural preemergence weed control in turf. In R.C. Carrow, N.E. Christians, and R.C. Shearman (eds.) Int. Turfgrass Soc. Res. J. 7:284-290. Parka, S.J. and O.F. Soper. 1977. The physiology and mode of action of the dinitroaniline herbicides. Weed Sci. 25:79-87. SAS Institute. 1990. SAS/STAT user’s guide. Vol. 2. 4th ed. SAS Institute, Cary, NC. 78 Environmental Research Table 1. Percentage reduction in crabgrass cover compared with the control by using different combinations of com _________gluten meal and pendimethalin tested in the field during 1995 and 19961._______________________ Pendmethalin Com gluten meal applied__________0___________ 29__________ 59__________ 88__________117________ Mean2 % Reduction 54 45 53 33 61 77 75 56 84 84 86 71 84 87 95 80 69 76 77 ANOVA Source d.f. M.S. Pr > F Year 1 1864.4 0.0007 4 Year*Rep 2429.3 0.0001 Treatment 19 1863.8 0.0001 Com Gluten Meal (CGM) 3 5554.9 0.0001 4 4400.7 Pendimethalin (Pend) 0.0001 12 95.4 CGM x Pend 0.8080 Year* Treatment 114.2 19 0.7474 Year* CGM 3 54.0 0.7833 4 Year*Pend 96.3 0.6365 Year*CGM*Pend 12 135.2 0.5537 Error 76 150.7 1Values are the average of visual estimates of two researchers. 2 Com gluten meal means are the average of three replications of five rates of pendimethalin applied in combination with each rate of com gluten meal observed over two years (n=30). LSD (0.o5 ) = 9% for the comparison of com gluten meal means according to Fisher's least significant difference test. 3 Treatment means are the average of three replications observed over two years (n=6). LSD (o.os) = 21% for the comparison of all treatments according to Fisher's least significant difference test. 3 Pendimethalin means are the average of three replications of four rates of com gluten meal in combination with each rate of pendimethalin observed over two years (n=24). LSD (0os) =11% for the comparison of pendimethalin means according to Fisher's least significant difference test. (gm -2) 0 49 98 147 Mean3 0§ 25 42 55 31 15 40 57 79 48 Table 2. Mean weekly turfgrass visual quality ratings during 1995 and 1996 for Kentucky bluegrass in response to _________increasing com gluten meal rates (n=30)1.__________________________________________________ Time after com gluten Com gluten _____ meal applied______________ 5_________________7________________ IT________________ 15________ Turfgrass Visual Quality Rating - ( g i n 2) 6 5 0 5 6 7 49 7 7 6 7 98 8 8 6 8 147 9 9 6 1 1 1 1 LSD (oos)3 1Means are the average of three replications of five rates of pendimethalin applied in combination with each rate of com gluten meal observed over two years. Values given are the average of visual estimates of two researchers. 2 Turfgrass visual quality was evaluated on a 9 to 1 scale: 9 = best quality, 6 = acceptable turfgrass, and 1 = poorest quality based on overall color, density, and uniformity. 3 According to Fisher’s least significant difference test. 79 Turf Management The Effects of De-icing Chemicals on Turfgrass - 1996 Trial David D. Minner and Barbara R. Bingaman Runoff from de-icing products applied to walkways and other hard surfaces results in damaged and dead turfgrass borders. The purpose of this study was to assess the level of damage caused by several common de-icer products. Our approach was to simulate a brine runoff by spraying salt solution directly on turf plots throughout the winter and evaluating injury during the growing season. In addition, we applied the de-icers in granular form to turf plots. The first year of this study was conducted in the winter and early spring of 1996 at the Iowa State University Horticulture Research Station north of Ames, Iowa. The experimental plots were in an area of established common Kentucky bluegrass. Brine solution de-icer study: Individual experimental plots were 2 x 4 ft with three replications. Because of possible de-icer runoff, each individual plot was completely surrounded by a 1-foot border. Treatments containing potassium chloride, 30% urea + 70% CaCl2, 50% urea + 50% CaCl2, 67% urea + 33% CaCl2, urea, rock salt, Safe Step (50% salt + 50% potassium chloride), magnesium chloride, and CaCl2 pellets were evaluated. A control was treated with only water for comparison. Application rates of 2, 4, and 8 oz/yd2 were used to simulate typical amounts of product used in the ice melt industry (Table 1). Treatments were randomly placed within each replication. The de-icers were dissolved in water and applied using a carbon dioxide backpack sprayer. TeeJet flat fan EVS #8008, white nozzles were used at 45 psi. Windbreak ‘cages’ were employed to prevent drift of the materials. No runoff or drift was observed after treatment differences became apparent. Nine applications were made beginning February 22 and ending March 19, 1996. A deer ‘cannon’ was placed to minimize browsing damage. Turfgrass ‘plugs’ were taken from each plot in replication 2 after the fifth application of materials. Two plugs were taken for each treatment. The plugs were placed into pots and maintained on a mist bench in the greenhouse until the grass began to green-up. This non-replicated evaluation was used for preliminary injury data half-way through the treatment period. Granular de-icer study: Individual experimental plots were 2 x 2 ft with three replications. Because of possible de-icer runoff, each individual plot was completely surrounded by a 1-foot border. Treatments containing potassium chloride, 30% urea + 70% CaCl2, urea, rock salt, Safe Step (50% salt + 50% potassium chloride), magnesium chloride, and CaCl2 pellets were evaluated. An untreated control was included for comparisons. Application rates of 1, 6, and 12 oz/yd2 were used to simulate typical amounts of product used in the ice melt industry (Table 2). Compared to the brine solution study, the granular study covered a broader range of application rates. Treatments were randomly placed within each replication. The amount of de-icer products equivalent to 10 individual applications was applied (Table 2). The materials were spread evenly over the plots. The products were applied on March 15, 1996. A deer ‘cannon’ was placed to minimize browsing damage. 80 Turf Management Phytotoxicity and percent living plant material data were taken for the both the brine and granular studies on April 10 and May 9 (Tables 1 and 2). Phytotoxicity was assessed using a 10 to 1 scale: with 10 = no injury and 1 = foliage completely brown. Percent living material was estimated as the percentage of green plant material per plot. Some of the plots, especially those treated with rock salt, were damaged by deer browsing. In these plots, the remaining plant material was considered to represent the entire plot in the data collection. On April 15, Kentucky bluegrass percent recovery data were taken on the plugs from the brine study that were maintained in the greenhouse. Recovery was assessed using a 10 to 1 scale: 10 = best recovery and 1 = no living plants (Table 1). Percent turf cover, percent weed cover, percent bare soil, turf quality, and turf color data were taken July 1 and August 28 for the brine (Tables 3 and 4) and the granular studies (Tables 5 and 6). Percent turf cover was assessed as the percentage of area per plot covered by turfgrass species and percent weed cover as the percentage of area per plot covered by weed species (broadleaf and grass species). Any areas devoid of turf or weeds were recorded as the percentage of bare soil per plot. Turf quality was measured using a 10 to 1 scale: 10 = best quality, 2 = weeds only, and 1 = no green material. Turf color was determined using a 9 to 0 scale: 9 = best, 1 = worst color, and 0 = no turf present. In the summer of 1996, the brine and de-icer experimental plots were sprayed with Roundup. The dead plant material was removed and the plots were seeded with perennial ryegrass at 2 lb/1000 ft2 using a drop spreader. Ryegrass seedling vigor and percentage ryegrass cover data were taken October 10 for the brine and granular studies (Tables 7 and 8). Ryegrass seedling vigor was assessed using a 10 to 1 scale: 10 = best and 1 = worst vigor. Percent ryegrass cover was determined as the percentage of area per plot covered by ryegrass. Results: Two separate experiments, brine spray and granular, were conducted to produce seven de-icer application rates: 0, 1,2, 4, 6, 8, and 12 oz/yd2. Repeated applications from the brine spray study combined with the single application from the granular study resulted in total winter application rates of 0, 10, 18, 36, 60, 72, and 120 oz/yd2. De-icer treatments applied during the winter caused a bleaching and light tan appearance to the dormant turf. This appearance remained visible for some treatments during spring green-up and was rated as phytotoxicity. The average of phytotoxicity on April 10 and May 9 indicated that all treatments had significantly more turf injury than the untreated control (Table 1). Urea-CaCl2 30/70 at 18 oz/yd2 had significantly less phytotoxicity than all other treatments except KC1. Percent turf cover and weed cover (Table 3) and turf quality and color (Table 4) were evaluated to determine recovery following de-icer affects. The average percent turf cover for July and August indicated that at the 18 oz/yd2 rate urea-CaCl2 67/33, urea, and MgCl2 had significantly less turf cover than the untreated control. De-icer treatments that resulted in poor turf cover also had higher weed cover. Treatments with high rates of urea (trts 7, 9, 10, 15, and 16) substantially reduced both turf and weed cover and resulted in plots with mostly bare soil showing (Table 3). 81 Turf Management Average turf quality and color for July and August, 1996 are presented in Table 4. At 18 oz/yd2 all urea + CaCl2 combinations, KC1, rock salt, Safe Step, and CaCl2 were statistically similar to the untreated control. Urea and MgCl2 had inferior turf quality. At 36 oz/yd2 all de-icer treatments had significantly poorer turf quality than the untreated control, however, urea + CaCl2, 30/70, KC1, and Safe Step were superior to urea + CaCl2 50/50 or 67/33, urea, rock salt, and MgCl2. At 72 oz/yd2 all de-icer treatments were similar and had very poor turf quality. The elements in some de-icer compounds are also essential elements for plant growth. Turf color was evaluated to determine if any beneficial color enhancement occurred, especially from urea treatments containing nitrogen. Urea combinations with CaCl2 enhanced turf color. Urea + CaCl2 50/50 provided the best color enhancement and was superior to the untreated control (Table 4). In the fall of 1996, the entire study area was reseeded with perennial ryegrass to determine if winter de-icer products inhibit fall re-establishment. Turf re-established from the sheer seeding for most treatments. Treatments 1,9, 10, 14, 15, 16, and 19 had significantly less turf cover after fall seeding than the other treatments. Treatments with poor re-establishment confirmed high rates of urea or rock salt. Brine de-icing treatments were repeated in the winter of 1997 on the ISU campus. The preliminary results from 1996 indicate that there are significant turf quality and phytotoxicity differences among de-icer compounds and rates. Data were analyzed using the Statistical Analysis System (SAS) version 6.08 and the Analysis of Variance (ANOVA) procedure. Fisher’s least significant difference (LSD) tests were used to test for treatment effects on turfgrass factors. 82 CO *uT3 C D • r* cd > O 0cd £ C O 0aj 3o.: o x CO J3 Cl O Oh 0a rn ^ 9 tx T3 v0^O D Ü ^ << <3 33 so <¿3 [N C O s3 O [3 CD 3X) ’C Tx a> S S-H 3 s4_j cd 3 ON jd Tc3d Ox & 3 CD 2 M 0XE oo ocxi 2a CO 0 C O *> Cd E O X) C 0 /Dox 3D C < o 3 Ox s o 33 3C D CD E S 3D < 3O > C OD x ON 0 T33 *S 3 0 3 s CO 0 t5 >> -3 Ox Ox 0 2CD —H 13 *c W x 0 eU O — 1 < oo en oo o o »n ^ (N o en VO —< oo r - —i 00 CN o^ JS Ox *3 ^ en O en oo un (N —i —< SO CN '—< N3 0>CT 3 ^ oa ^3 0 0 3 -a O oo un ^ un ^ t> CNI oo O ^ tei O OOt> CN^ uS ^ ^ ^ 00 so CN S ^3 oo SO so en en *—■ (N SO r- r- O O (N »-î *-< un CN —i oo s o O Ors so (N — r^ *— 1 en r- - (N rn h —< en t"~ ^ TT 0 0 (N r r oo CN ^ r - r + + + + + + + + cd cd cd 5 P 5—i 5—( 5—i £0 ox ox £o o£ o^ £ £ £ LD x ëè C CJ u + C1D T3 Od r - i> en en un un un SOso so N® un so o t^ o un h en O nr ^ r"~ en n f CN C DC Dcq rq t> o un ^ -J t"~ en O CN ^ ^ (N 00 so (N oo so (N OO so (N oo so CN os t> M TT OO N® r"~ o oo CN CD OO CN O en 1 »—1 un CN —i n® oo Os O en h ^ cd cd cd G0 CO 00 N® N® ^ D DD ^ CN en T t un so 83 o o o CO CO co nr nr ^r CD CD CD 0 , Ox Ox CD OJ CD a a a GO 55 55 C JC JO;............... J* ¿à JX O O CJ c £ ^ r- o oo ox ox ox r-> o r - ^ cd 00 SO CN r-^ en en C'' en r - N® UUU IN (N - J .0 U-H c £ 3 3 3 CO GO c/o S S Siu u u O CN en d - us so t oo (N (N CN CN CN CN CN (N CN L SD qqs_____________________________________________________ <19__________ L2 ________ 0_9_________ 9__________ 17__________ U ________ nonrepiicated Phytotoxicity was assessed using a 10 to 1 scale: 10 = no injury and 1 = foliage completely brown. Percent living plant material was assessed as the percentage of area per plot covered by green material. Plugs were taken from rep 2 on 3/4/96 after 5 treatment applications. Percent recovery was assessed using a 10 to 1 scale: 10 = best recovery and 1 = no living plants. Turf Management — (S C-> (N O O -h r- vo VO CS -H VO r-H p-H OS — I un CS OO ^ Table 2. Phytotoxicity and percent living green plant material data for field plots treated with de-icing products for the 1996 Granular De-icer Study. a> 0 3 £ •*—» c0 3 e 3 O & O un cs — < os -H o o vn —' ^ un*H^ OO C^ OS C" O o o o cs o o cs p o p p cs p Os P^ vo N© ox m c- cs — ■ r- es rf cn es CU < p © CSI CS C" m o ^ ^ OO 00 -3 ^ O es p p o en ^ es p O es es p ^ ^ l> *-< ^ Tf ^ ^ *-<’ —3 oo Ö e 3 lU ìCd h £ o o o o & o OÑ 6 ^ o p p p o o p o p Os ^ ^ en p p _■ os *-3 — ¡ OO © p o p ’■—< vo p-^ P P P oo »— 3 3 OS ¿S' e s s •1.6b g ^ O Ä O 2 « il 5 T3 ed Il C m ü C 2 O T3 03 ^ pH a a T3.S O *3 VO CS co co cd vo cs vo CS N O S 'S CO Magnesium chloride was applied at 1, 6, and 12 oz a.i. Mg C hwas 47% a.i. so the applied amounts were 2.1, 2.8, & 5.6 oz for a total of 21, 28, & 56 oz. Turf Management o— < (D CO ___ co ed ço o 3 O CD ûû * ir co .S «* co > 3 ^ TD cd + + + 3 co fi cd N=> N ® \ 5 ox ox ox r- e- Q cd cd cd CO C/D C/3 cd cd £o £o £o O U U cd Ö 2 a cn cn cn >¿ U U D D D OO OS O -Uí ^ ^ O O O o o o C2 CU CU CÙ CD - cd cd cd CO CO OO cu X — 2O o(D -fi — M VO o 0 un os oo m m oo vo (N os m m oo vo CN oo vo (N oo vo (N OO VO (N OO vo CN OO vo CN OO vo CN — m m —i m t> — en M — en M — en m — m M — m M en M un — en M ^ (N ^ oo (N t> Ü M M M Q- CL CL s *03 O ÍN 3— co co co + + + + + T(D 3 X \ \ 4Q— 4— *JD 4— > J*JD r- r- ox ox ox C/3 C/5 C/3 CO in cO aa^ ^ ^ 3 3 3 DQ> 0> a a a GO OO CO C D PD DDD DDO 55 < 5 555 U O CJ-.......... 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Turf quality and turf color data for field plots treated with de-icing products for the 1996 Granular De-icer Study. r- on o o on o © r- o r- © © o 3^ 3 N —< O NO VN « oo" 3 |i § 3 C"» CN CN 00 CN CN NO CN CN r - CN CN OO ON (N (N t> (N -H —< 3 CD 33 a CN 1CU O'' 3 ^ o cd £ h 3 ^ 3 .. CN - nc-- 3 3 3 CU d i V---' V---/ V---' CD CD CD ox ©x ox cd cd cd CU I 8 (N Ot rOO ON S s o c £Cu 8 fe b T3 u-(‘"V , s/3 H 5 .2 C o < L ) ^ o C os ON O ,^r o o o o o o o o o o o o o rso I T) wn en no r- *n o o o o o o en O N O N O N O N O N O N O N O N O O O N O O O O O N O O O N O N O N O N O O O O O O s es ü 55 VO O on < D JO cd cr a 'e .è“ " d - e n OOCDOONONCNi / n ^ CNi / n i OT j - NOwn u n c N a o o o cr oo .S «á vi o T 3 D J< O X > c d i-o, £ X OS8 O . .O 53 V O O S ON X X X X § O . g Il J3 a «> ^ _ T3 üOh ^C x x x x x x x x O£•§ o *> a O .o T5 o •a >,.s ’2 S -o ^ o O a> o 8 g£ s < D ç§ -O O ■C w O o Ccd/3 o < D « i5 tO d " u* h X X o > Cd cd O _ o T3 X X X X X X 1/3 ^ s &O > > £■ ? +d ÖÜT3 e.) 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They were planted in Rep 2 only. West CM or oo 94 Mean oo East Uh 12-inch Table 3. Soil temperatures on October 10, 1996 in turf plots included in the 1996 Steam Line Study.____________________________________________ Turf Management Turf Management OS SO *0 VO VO o o o v o r ^ m ( N ( N O O t > r - » o r ^ u ^ o o ’^- r- ^.vor-r-oooooocovovo^rr-m^-m^cN r- VO V O ' 0 ' 0 VO V O V O ' O V O V O VO V O V O V O VO V O V O O: 2 3 .Sj (N 3 OO w vo r— O cn Ni V > ro-v- rr )- (r N ^ tO^ C v> o r( N - ' ro^r( 'Nï O > t— Os O o oo or ^cr N ^ r ^^ ro^or -o' vo oovootv^o nv o- v^ ovvoo»v on vvoov^o vo r" oo vo < D Q « H Ô ¿ — + 0> 3 o co , CO CO 3 ob .2 CO ¡02 3 H >> O N uo so o s o ^ c n c o ^ - voso 98 r- oo os o J-361 5 ° c U 0D Û < J3 23 2 ôû j -o J-361 12 & & J-554 a 24 J-371_________________________________________________ These grasses were not replicated. They were planted in Rep 2 only. 2no ”0 22 s H 21 Table 4. 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