1983 IOWA TURFGRASS FIELD DAY AND EQUIPMENT SHOW Thursday June 30, 1983 IO W A STATE U N IV E R S IT Y H O R TIC U LTU R A L R ESEA RCH S TA TIO N A M E S , IO W A Many of the projects at the field research area have now been established for nearly 4 years. The first cultivar and management studies were seeded in August, 1979. The area was expanded in 1980 to 3.2 acres and in 1981, an additional 1 acre was seeded and studies were begun. Plans are presently under way to further expand the area by another 3 acres in 1984. The first research report was printed for the 1981 field day, which was held on June 18 of that year. An expanded research report was compiled for the next field day which was held on July 29, 1982. The following report is the third to be printed. It includes 1982 data from the field research projects, as well as a number of other turfgrass investigations being conducted at Iowa State University. The expansion which has taken place since 1979 was made possible through grants from the Iowa Turfgrass Institute, the Iowa Golf Course Superintendents Association, and through donations made companies listed at the end of this report. by the The profits from activities such as the field day, the Iowa Turfgrass Conference and the 1983 golf tournament are very important in making research projects of this type possible. On behalf of the Iowa Turfgrass Institute and Iowa State University, I would like to thank you for attending this year's field day. Nick Christians June, 1983 1 Acknowledgements I would like to acknowledge Mr. Jeffrey Nus for his work in helping to establish the turfgrass research area over the past M seasons. Appreciation is also expressed to David Brahm, Sally Johnson, and Thomas Robeson for their efforts in developing the area. I would also like to acknowledge Dr. Charles V. Hall for his direction and help in establishing the turfgrass research program at Iowa State University, and to thank each of the past and present members of the board of directors of the Iowa Turfgrass Institute for their encouragement and support. Nick Christians June, 1983 2 PROGRAM Thursday June 30, 1983 9:30 a.m. to 3:00 p.m. 8:00 - 9:15 .............. Registration and Coffee with exhibitors 9:15 - 9:30 .............. Opening remarks and introductions 9:30 - 12:00..............Tour of Research Area 12:00 - 1:30..............Lunch 1:30 - 3:00 .............. Afternoon Educational Program In case of rain, an indoor morning program is planned at the research station. 3 MORNING PROGRAM There are 10 studies on the research area that we will be looking at this morning. Most of the areas in today's program are either new or are different from those which were viewed at last year's field days. There is a number on the back of your lunch ticket which corresponds to 1 of the 10 areas. At 9:30 you will be instructed to go to the study with the same number as that on your ticket (see map). There will be 15 minutes allowed for each stop. Each presentation will last from 7 to 8 minutes and there will be approximately 5 minutes for questions. At the end of 13 minutes a horn will blow and your group will have 2 minutes to move to the next stop. Each group will see all 10 research areas. There are more than 10 studies on the research plots. Many of those investigations will have signs on them. Please feel free to visit any of these areas during lunch or after 3:00. The staff involved in presenting the morning program will be available for questions throughout the day. The research areas that will be discussed this m orning individuals who will be presenting the information are as follows: and 1. Chemical Disposal Facility Dr. Charles V. Hall, Head, Department of Horticulture, Iowa State University 2. Iron-Nitrogen Studies Nick Christians, Dept, of Horticulture, Iowa State Univ. 3. Bentgrass Cultivars Sally Johnson, Dept, of Horticulture, Iowa State Univ. 4. Tall Fescue Control Studies Brian Maloy, Dept, of Horticulture, Iowa State Univ. 5. Perennial Ryegrass Cultivars Tom Fermanian, Dept, of Horticulture, Univ. of Illinois 6. Fall Fertilization Study Norm Hummel, Dept, of Horticulture, Iowa State Univ. 7. Prairie Grass and Wildflower Establishment James Midcap, Dept, of Horticulture, Iowa State Univ. 8. Growth Retardant Studies Ken Diesburg, Dept, of Horticulture, Iowa State Univ. 9. Turfgrass Cultivar Trials David Brahm, Dept, of Horticulture, Iowa State Univ. Kentucky Bluegrass Cultivar Evaluations Robert Shearman, Dept, of Horticulture, Univ. of Nebraska 10. 4 the Afternoon Program There are four demonstrations planned for our program afternoon. this The program will begin at 1:30, and each of the four stops will be 20 minutes long. Groups will be divided according to the number on the back of the lunch tickets. At the end of the 20-minute period, a horn will blow and your group will proceed to the next area. After the program, feel free to stop back at one of the stations or visit the equipment demonstration area. This afternoon's program should be both enjoyable and educational for all involved in professional turfgrass management. Here are the topics and the individuals presenting the program: 1. Weed Identification Bob Hartzler, Extension Associate, Weed Science, ISU 2. Grass Identification Norm Hummel, Extension Turfgrass Specialist, ISU 3. Tree Spraying Al Duey, Jay-Lan, Inc. 4. Recognizing Herbicide Injury Gene Rozenboom, Linn County Extension Associate, Pest Management 5 Wildflower and Native Grass Establishment Study Premium Fall Fertilization 6 Buffalograss Study I s,ud> Tall Fescue Control Study Baron Parade escue Tall Fescue Control Study Tall Fescue Management Study Summer 1983 Growth Retardant Timing Study 8 Sod Production Study P. Ryegrass cultivar Evaluations Tall Turfgrass Research Plots Baron Sod Blend 4 Baron N & K Study Phosphorus Fertilization Demonstration Non-lrrigated : Fine Fescue Management Study Irrigated Kentucky1Bluegrass Management Study Non-lrrigated j Irrigated Perennial Ryegrass Management Study I Bentgrass Cultivar £ Study Creeping Bentgrass B.G. Weed Control Study Buffalograss Management Study Texoka B.G. Fert. Study Common Sharps Perennial Ryegrass Cultivar Evaluations Kentucky Bluegrass Cultivar Evaluations - ^ T a l l FescueKentucky Fine Fescue Bluegrass Cultivar Seed Mixtures Trials Baron i_ I Sod Park Reestablishment Study I Tall Fescue Regional Trials Enmundi Emerald Penneagle Penncross Fungicide Trials Fall Topdressing Study Emerald Penneagle Penncross Iron Nitrogen Study Pythium Control Study Fall Topdressing Study Controlled Release Nitrogen Fertilization Study Growth Retardant Study I I Park Iron Nitrogen Study Sod Establishment Study N Building 6 Regional Kentucky Bluegrass Study "Low Maintenance” Map of New Field Research Area Established in the Fall of 1981 Parking Area Maintenance Building Regional Kentucky Bluegrass Study "High Maintenance" 155’ Growth Retardant Studies Road <- 253’ Total Area 7 39,215 f t 2 0.90 Acres > Environmental Information in the 1982 Season The next two pages include information on the environmental conditions at Ames in the 1982 season. The 1982 season was cool and wet. May was a particularly wet month, with some precipitation reported nearly every day. The plots of rainfall and temperature are representative of one of the many ways in which the computer is being used to increase the efficiency of the faculty and staff at Iowa State University. The 1982 environmental data were entered on the computer by Dr. Henry Taber of the Horticulture Department. He then sorted the information, calculated means, and printed the graphs exactly as they appear on the next two pages. The entire process, which has previously required days to complete, required 4.1 seconds of computing time once the information had been entered into the computer memory. 8 TEMPERATURE 1982 F itili “:2 33;;444444bbbbbbGCGCGC 1 i ¡ 11 78868889999990CC0C Gì ì22 C C i i2 2 GC i12 2 CG i12 2 C G ii2 0 0 ii2 2G0 i i 2G G 1 l2 bCh.QS.C 49 4 9 49 4 9 49 4 938 28 28 38 38 28 2 72 72 7i6 iC 1C i0 i6 L MONI H DH Ì Average maximum and minimum temperatures in Ames for the 1982 growing season. 9 RAINFALL 1982 INCHES 01 122 3001 122001 122001 122001 122001122001 122001 12 50505049494949494938383838383827272716161616161 M 0NTHDAY Rainfall in the Ames area for the 1982 season. 10 Table of Contents Environmental Information in the 1982 Season.................... 8 Kentucky Bluegrass Cultivar Evaluations........................ 13 High Maintenance and Low Maintenance Kentucky Bluegrass Regional Cultivar Trials................. 16 Fine Fescue Cultivar Trial..................................... 22 Tall Fescue Regional Trial................... 24 Bentgrass Management Study..................................... 26 Kentucky Bluegrass Management Study............................ 28 Perennial Ryegrass Management Study............................ 34 Fine Fescue Management Trial................................... 37 Perennial Ryegrass Cultivar Evaluations........................ 39 Growth Retardant Study 1 ....................................... 41 Growth Retardant Study II...................................... 45 1982 Broadleaf Weed Control Studies............................ 49 1982 Preemergence Weed Control Studies......................... 57 Tall Fescue Phytotoxicity Screening Study...................... 64 1982 Postemergence Annual Weed Control Study................... 65 Origin of Increased Ethylene Concentration Associated with the Development of Leaf Spot in Kentucky Bluegrass 'Newport'......................................... 67 Late Fall Fertilization Study.................................. 68 Nitrogen Fertilization Study................................... 69 Insecticide Screening For White Grub........................... 72 Results of 1982 Turfgrass Disease Control Trials............... 74 Liquid Fertilizer Screening-1982............................... 77 Buffalograss Management Study.................................. 80 Direct Low Temperature Damage of Bentgrass..................... 11 83 Table of Contents Page 2 Phosphorus Fertilization Study................................. 91 Folian Study................................................... 9^ N X K Study.................................................... 97 Postemergent Herbicide Rate Study-1982........................ 100 00 00 00 • o• O co 00 rH i— i O o 1—1 o • o 1—1 o • o o o m in • r^> • vO • r>- • MD CM • o rH co o rH rH m O uo rH 00 CM UO n- UO uo rH U0 00 Nj\— 1 rH o • UO • U0 1 00 00 X- • uo • vO o • vO • vO CM rH O CO CO O uo CM CM 00 CM NT n- oo vO o 00 CO CO CM CM m 1—1 O u C CM O VO o rH rH rH rH pci CO CO CO m CM PQ X co < PQ o vD O CO CO ¡3 O O O O uo hQ W o U0 o o uo hQ w CM i—1 CM uo rH u u u & U O O CO CU < < w w in vO n- 00 PQ ¡3: CM X-1 cu u rC u PQ CO 43 * r- 00 00 00 00 oo vO rH m m m m m m vo vO vO r ^* m m n- r^ o m o o o o m vO vO vO 00 00 00 o O m vO m m • m o 00 00 o in m m rH m o O vO vO rH m O m vO m rH LO 0) 00 oo vO vO m rH m O rH CM té 6urs after a 1.5 inch rainfall. The crabgrass was in the 2 to 3 leaf stage and the broadleaf weeds were actively growing. The first evaluations of phytotoxicity were made 24 hours after application. At that time, there was phytotoxicity on the Kentucky bluegrass . beginning to curl after only 24 hours. at 72 hours on 6/19 (Table 30). no visible evidence of The dandelions were A second evaluation was made On this date, and again on 6/29, some visible phytotoxicity was apparent on the Kentucky bluegrass in plots treated with Daconate 6 and MCPP + 2,4-D (treatments 2 and 3). damage was present on the bluegrass in any of the other No plots following either of the applications of Daconate 6. Evaluation of weed control were performed on July 7, 1982. All treatments reduced crabgrass and dandelion population in comparison to the control at this location (Table 30). among treatments There were no differences with regard to crabgrass control, as would be 65 expected. There were also no real differences in dandelion control among the treatments. of the MCPP It would have been expected that the addition + 2 , 4-D would have provided much better control of broadleaves than the Daconate 6 alone. In this study, however, Daconate 6 alone showed a 91-92 percent control of dandelions. There were no broadleaf weeds in plots treated with the Daconate 6 and 2,4-D + MCPP combination. Table 30. Postemergence weed control data from the 1982 study at the North Dakota Avenue Cemetery in West Ames. Treatment Rate Date of App. Crabgrass Dandelion 1*# 1 0 0 2 2 96 100 2 2 97 100 5/16 1 1 92 91 2 5/16 1 1 94 92 2 5/26 1 1 21 35* - 1. Control - 2. Daconate 6*+ 2 MCPP + 2, 4-D Amine 2 Daconate 6 (10 days later) 2 5/26 Daconate 6 + 2 5/16 MCPP + 2, 4-D Amine 3 Daconate 6 (10 days later) 2 5/26 4. Daconate 6 2 5. Daconate 6 Daconate 6 (10 days later) 3. Phytotoxicity 6/19 6/29 5/16 LSD 5* 2 *A11 treatments were applied in 3 gal water per 1000 ft . 5' x 5'.* **0n a scale of 9-1; 1 = no damage, 9 = dead turf. 66 Plot size = S3 tjm Origin of Increased Ethylene Concentration Associated with the Development of Leaf Spot in Kentucky Bluegrass 'Newport* by L. W. Coleman and Clinton Hodges Leaf spot results in increased levels of ethylene found within infected leaves of Kentucky bluegrass 'Newport'. The elevated ethylene concentration is observed 12 h after inoculation and occurs prior to observable lesions. It is necessary to understand how ethylene is formed and what role, if any, ethylene plays in disease development before attempts are made to control leaf spot or other diseases by manipulating the physiological status of the plant. Currently, a method is available that detects the activity of the enzyme thought to control the formation of ethylene in plants. Preliminary work indicates that the determination of the origin of ethylene from vegetative tissue may be difficult. of the current method, With modification it is hoped that the source of ethylene associated with disease can be found. If the source of ethylene in diseased tissue is learned, and if ethylene proves to be a significant factor in the development of disease, then treatments designed to minimize its effects can be developed. However, expression, if ethylene plays only an insignificant role in disease then it will be necessary to continue searching for factors that cause plant injury. 67 LATE FALL FERTILIZATION STUDY by Norman Hummel In this experiment nine N fertilization programs compared for late fall fertilization. are being The treatments are listed below: Approximate Time of Application Number April 20 1.25 urea 0 0 1 2 3 4 5 6 7 8 9 0 0 0 1.50 IBDU# June 1 1.0 1.0 1.0 2.0 1.0 2.0 0 1.0 0 urea urea urea CIL* CIL AIM+ urea August 10 0.75 0.75 0.75 0 2.00 0 2.00 0.75 0 urea urea urea CIL AIM urea Sept 20 1.0 1.0 1.0 1.0 0 2.0 0 1.0 1.0 urea urea urea urea AIM urea urea Nov 10 0 1.25 1.25 1.00 1.00 0 2.00 1.50 1.50 urea CIL urea CIL AIM IBDU IBDU * Sulfur-coated urea manufactured by Canadian Industries Limited „ Sulfur-coated urea manufactured by Lakeshore Equipment & Supply Co. F Isobutylidenediurea distributed by Par Ex The test was begun on September fertilizer treatments were applied. 30, 1982, the first Plot size is 4 x 8 feet. late fall treatments were applied on November 10. September when The Since most of the treatments were 1.0 lb N from urea, no data has been collected to date. There were no observed differences between the 1.0 urea and the 2.0 AIM treatments. Data to be collected include bimonthly assessments of color and bimonthly determination of fresh weight clipping yields. Yields will be obtained by making a single pass up the center of each plot using a rotary mower. Clippings will be collected and weighed. 68 NITROGEN FERTILIZATION STUDY by Norman Hummel In this experiment five nitrogen sources are being evaluated at different rates and timings of application fertilization of Kentucky bluegrass turf. for maintenance The treatments include Lakeshore sulfur-coated urea (SCU), Andersons SCU, IBDU, and Ureaform applied at 2, 3, and 4 lb of N/1000 sq ft/year. The treatments were either applied in one or split into two applications. applied at 2, 3, and 4 lb N/1000 sq ft/year split Urea was into four applications. The highest color ratings following the first fertilization were produced by the Andersons SCU when applied at the 2 and 3 lb rates. Dark green color was also produced by the highest rate of urea and the 3 lb rate of Lakeshore SCU. Acceptable color was produced by ureaform at the 2 and 3 lb rates. However, color response was initially slow on plots fertilized with ureaform at the 1 lb N rate. Poorest initial response to fertilization occurred on plots fertilized with IBDU, at all rates. Two weeks after fertilization, color ratings from IBDU plots tended to be no higher than the check plots. Three weeks after fertilization, however, color on IBDU plots was acceptable and continued to improve for several weeks, especially at the higher rates. Through the summer, IBDU at the two and three pound rates produced excellent color. Good color was m a i n tained throughout 69 the summer for all treatments, except for those that did not receive a spring application of N. In early September (9/9), most of the Lakeshore SCÜ and IBDU treatments continued to produce good color (Figure 1). However, most of the ureaform treatments and the 1 lb rate of the Anderson's SCU did not provide acceptable color. Three months after fertilization (9/27), the only treatments that produced acceptable color were the Lakeshore SCU treatments applied at 2 and 3 lb N/1000 sq ft in the spring. These results suggest that the Anderson's SCU is a quicker releasing material than the Lakeshore SCU (Figure 1). Although clipping yields were not taken, it was observed that the dark green color produced by Anderson's SCU after fertilization was accompanied by much topgrowth. Use of the Anderson's SCU may necessitate splitting the annual rate of N into three applications to produce uniform quality turf without producing excessive growth. Although it required more applications, urea, even at the lowest rate, produced turf of acceptable quality throughout most of the season. It is impossible to draw any valid conclusions from the first year's data. Since many treatments received high rates of N in the * fall rather than spring, observations need to be made this spring and summer to compare various treatments. It is also expected that more differences will be observed in the future as the inherent soil N is depleted. 70 NOT FOR PUBLICATION COLOR COLOR COLOR Figure 1: 71 INSECTICIDE SCREENING FOR WHITE GRUB by Norman Hummel and Donald Lewis Several insecticides were screened for control of the masked chafer white grub (Cyclocephala spp.). This study was conducted at the Logan-Missouri Valley Country Club, Harrison County, Iowa. In 1982, two new insecticides received labels for white grub control in Iowa: Oftanol 5G (Mobay Chemical Corporation) and Turcam 80SP (BFC Chemicals Inc). An experimental compound (Ciba-Geigy 12223; Triumph) is expected to be released soon. Diazinon and Dursban are insecticides that have a tendency to tie up in thatch, thus decreasing their effectiveness. By applying them in conjunction with a wetting agent, it was hoped that the insecticides could be moved rootzone where the grubs are feeding. were applied on August 5, 1982. to the These, and other insecticides, The treatments are listed in table 31. Grub counts were made on September 16. Due to a very low grub infestation, there were few significant differences between treatments. However, trends were noticed. the The Ciba-Geigy 12223 and Dasanit were the top treatments, with no grubs found in a 12 square foot sampling area. Although Dasanit is labeled for turf, it is extremely toxic and less toxic materials are generally recommended. Excellent control was also given by Oftanol, Turcam, and Diazinon + wetting agent. Dylox. Fair control was obtained from Diazinon, Ethoprop, and The Dursban treatments gave poor control. Again, it must be stressed that the control of white grubs given by most of these 72 treatments was not significantly different. Table 31. Results of Logan-Missouri Valley C. C. White Grub Study Treatment Rate 0z/1000 ft2 % Control Ciba-Geigy Triumph 0.75 100a Ciba-Geigy Triumph 1.50 100a Dasanit 15G 6.25 100a Diazinon + wetting agent 5 + 2 95a Oftanol 5G 14.50 95a Turcam 80SP 1.00 91a Diazinon 4EC 4.00 82ab Ethoprop 8.00 68ab Dylox 80SP 3.75 64ab 5 + 2 55ab 5.00 36bc Dursban + wetting agent Dursban Check 0c 73 RESULTS OF 1982 TURFGRASS DISEASE CONTROL TRIALS L. E. Sweets Iowa State University Selected fungicides were tested in field trials for efficacy of control of Helminthosporium leaf spot (Helminthosporium sorokinianum) , dollar spot (Sclerotinia homoeocarpa) and Pythium blight (Pythium aphanidermatum) . Trials were conducted on the Turfgrass Research Plots at the Horticulture Research Station. In both trials, fungicides were applied to Penneagle bentgrass maintained at 1/4" cutting height. Application was made with a modified bicycle sprayer at 30 lbs. p.s.i. and a dilution rate of 5 gallons per 1000 square feet. The experimental design was a randomized block plan with four replicates, plot size 4x5 feet. Fungicides were applied on a 7, 14 or 21 day schedule as indicated in either Table 32 or 33.Applications began on June 2, 1982 and continued through September 22, 1982. 1. Helminthosporium Leaf Spot/Dollar Spot on Penneagle Bentgrass The purpose of this trial was to compare the relative efficiency of standard and experimental fungicides in the control of Helminthosporium leaf spot and dollar spot. Fungicides included in the trial along with rates of application and spray schedules are given in Table 32* The trial was con­ ducted in an area with a history of leaf spot problems. However, during the 1982 season, neither Helminthosporium leaf spot nor dollar spot was severe in this plot area. Disease ratings were made on August 10 and August 24. Ratings were made on the basis of the percentage of plot area showing leaf spot symptoms. Results of ratings are also given in Table 1. 74 Table 32. Rates, spray schedules and efficacy of fungicides tested in Helminthosporium leaf spot/dollar spot trial. Rate of Formulated Product (oz./lOOO sq. ft.) Time Interval Between Sprays (Days) Tersan 1991 1.0 14 9.1 7.2 Duosan 3.0 14 6.0 5.6 Vorlan 2.0 14 6.2 4.3 Cadminate 0.5 30 12.4 8.5 Fungo 50 1.0 14 16.5 8.2 Bayleton 25 1.0 14 6.4 4.5 CGA-64250 0.5 14 12.5 5.82 CGA-64250 1.0 14 10.8 3.62 Chipco 26019 2.0 14 5.2 4.8 Daconil 2787 3.0 14 14.5 10.6 Daconil 2787 6.0 14 8.4 5.1 Dyrene 4.0 14 15.1 8.2 Dyrene 6.0 14 10.5 6.1 Fore 6.0 14 17.2 9.2 Fore 8.0 14 12.5 7.3 Acti-Dione RZ 1.2 14 17.1 8.7 Acti-Dione TGF 1.0 14 15.4 7.0 20.6 16.4 Treatment Check Average of ratings from four replicated plots. showing leaf spot symptoms. 2 Based on percentage of plot Plots treated with CGA 64250 showed some Mgreeningn of turf. 75 Disease Rating'*' Aug. 10 Aug. 24 2. Pythium Blight on Penneagle Bentgrass The purpose of this trial was to compare the relative efficiency of standard and experimental fungicides in the control of Pythium blight. Fungicides included in the trial along with rates of application and spray schedules are given in Table 2. Although the trial was located in an area with a history of Pythium blight, no Pythium blight symptoms were visible when the trial was initiated. Environmental conditions were not favorable for disease development during the 1982 season and no disease developed in the plot area. Therefore, no disease ratings were made on these plots in 1982. Table 33. Rates and Spray schedules for fungicides included in Pythium blight trial. Treatment Rate of Formulated Product (oz./lOOO sq. ft.) Time Interval Between Sprays (Days) Subdue 2E i 14 Subdue 2E 2 14 Subdue 2E 2 21 Koban 2-4 1/2 5-10 Banol 2 14 Banol 4 14 Banol 4 21 Tersan SP 4 Fore 8 Acti-dione RZ 1.2 as needed 5 7-14 Check 76 Liquid Fertilizer Screening - 1982 by Sally Johnson A fertilizer screening study was conducted in 1982 to evaluate a number of liquid fertilizers for potential to burn turfgrass foliage. Treatments were applied with the Spreader King liquid lawn care applicator at rates of 0.25, 0.50, and 1.0 lb. N/1000 sq. ft. in June and July, and at the rates of 0.50, 1.0, and 2.0 lb. N/1000 sq. ft. in August. Materials were applied as a low volume spray, and a non- diluted form of liquid fertilizer was applied when possible. Fertilizers were not watered in, and were applied during midday. Turfgrass was given a visual rating for degree of fertilizer burn. The scale was from 9-1; 9=no visible burn and l=dead turf. Ratings less than 5.0 were considered unacceptable. The study was designed in a randomized complete block with 28 treatments and 3 replications. The entire study was repeated 3 times in 1982. Table 3**. Fertilizers used in the 1982 Liquid Fertilizer Investigations. Fertilizer Nitrogen Source Analysis Fluf Fluf-Plus Tuf Fan Fan N-P-K Formolene Folian Urea Form. + Urea Methyleneurea Methyleneurea Methyleneurea Alkyleneurea Alkyleneurea Methylolurea Urea Urea Methylol & Urea 18-0-0 17-0-0 18-0-0 20-0-0 16-2-5 30-0-2 12-4-4 17-0-0 20-2-6 77 Burn lb. N/Gal. 1.70 1.66 1.77 1.90 1.62 3.25 1.17 1.36 2.02 Results: Table 35. Average fertilizer burn ratings for treatments applied in June and July, 1982. Fertilizer 0.25 lb. N/1000 ft. sq. 0.50 1.00 Fluf-Plus Fluf Tuf Formolene Formolene + Urea Fan N-P-K Urea Folian 9.0 9.0 8.0 8.0 8.5 8.0 8.5 7.5 8.5 8.5 8.0 7.5 7.5 7.0 5.5 6.0 8.5 7.5 7.0 5.0 4.5 4.5 3-5 3.5 F,S*D * 0.05=1*5 Table 36. Average fertilizer burn ratings for treatments applied ii August, 1982. Fertilizer 0.50 lb. N/1000 sq. ft. 1.00 2.00 Fluf-Plus Fluf Tuf Formolene Formolene + Urea Fan Fan N-P-K Urea Folian 9.0 9.0 8.5 8.5 8.5 8.5 7.5 8.0 7.5 9.0 8.5 9.0 8.0 7.5 7.0 5.0 6.0 6.0 8.5 8.5 7.5 7.0 5.5 5.0 5.0 4.5 4.5 All of the materials tested can be safely applied at 0.25 lb. N/1000 sq. ft. with minimal phytotoxicity. The ureaform materials, Fluf, Fluf-Plus, and Tuf, caused little foliar burn, even when applied at the 2.0 lb. N/1000 sq. ft. rate. Formolene gave good results up to 0.5 lb. N/1000 sq. ft., but could not be consistently applied at the 1.0 lb. rate without phytotoxicity. It should be reemphasized that these were low volume applications. 78 The Formolene + Urea solution behaved much the same as Formolene, but was much more phytotoxic at the 2.0 lb. rate. Fan and Fan N-P-K, both alkylene ureas, gave good results up to 0.5 lb., but were very phytotoxic at higher rates. Folian and urea showed the greatest tendency to burn, and the results of this study indicate there is no difference between these materials when considering burn potential. In this study, conditions were chosen which would be expected to favor foliar burn. This was done to test the Spreader King and the fertilizer products under the adverse conditions which may occur during commercial use. By watering materials in, by using larger volumes of water during application, by avoiding midday heat, and by applying only when the turf is actively growing, the potential for foliar burn can be decreased considerably. 79 Buffalograss Management Study by David Brahm This study was seeded June 16 of 1980 as an evaluation of three buffalograss cultivars under various management practices. Cultural methods include three mowing heights (no mow, 2.5 cm, and 5 cm) and 2 three fertilization rates (0, 1, and 2 lb N/1000 ft /yr.). N/1000 ft 2 The 2 lb treatment is split into two applications of 1 lb N/1000 2 ft , with one being applied June 1 and the other July 15. The area is mowed once a week and watered as needed to prevent drought stress. Each treatment is replicated three times and monthly. data is collected Due to a severe encroachment problem of cool-season grasses into the buffalograss treatment area, a study to screen several herbicides which selectively controlled cool-season grasses was established in May of 1982. Information gathered from this study showed that simazine, at the rate of 2.0 lb a.i./A, provided the best control of cool-season grasses along with preemergent control of annual weeds. Simazine also had no phytotoxic effect on buffalograss. Simazine was then applied to the management study to remove the coolseason grasses. As shown in table 37, the quality of all three cultivars improved after the application of simazine. This was due to the removal of competition of both the cool-season grasses and annual weeds. The data acquired in 1982 indicates buffalograss varies with mowing height. provided the most acceptable turf, while that quality of The 2.5 and 5.0 cm height the exhibited the poorest quality turf (Table 38). 80 the no mow treatment This poor quality could be attributed to low density which occurred due to shading by the previous season's growth. In 1983 the treatments will be mowed uniformly at 5.0 cm height in early April to alleviate the shading problem. Table 39 contains information on the combined effects of mowing height and simazine. At all three mowing heights the addition of simazine improved the quality of the three cultivars. Again, this was probably due to the removal of competition from both the cool-season grasses and the annual weeds. This study has provided a better understanding of the management of buffalograss and some of the problems which confront it under higher maintenance conditions. n o n - irrigated Data will be taken this season on a b u ffalograss observations last season, the management study. non-irr i g a t e d From general study looks very promising. Another investigation that will be continued this season is the herbicide study which is designed to observe various herbicides that s e l ectively control cool-season grasses in a buffalograss turf. Results of this study will be presented in 1984. Table 37. Effects of simazine on the quality of three cultivars of buffalograss (1982). Simazine (lb a.i./1000 ft^) Texoka 0.0 2.0 LSD (0.05) 81 Sharp's Common 2.5 4.5 2.5 3.5 2.5 4.0 0.5 0.5 0.5 Table 38. Effect of mowing height on the quality of three cultivars of buffalograss (1982). Mowing Height (cm) Texoka Sharp's Common no mow 2.5 5.0 2.0 4.0 5.0 1.0 3.0 4.0 1.5 3.5 5.0 LSD (0.05) 2.0 1.5 1.5 Table 39. Interactive effects of mowing height and simazine on the quality of three cultivars of buffalograss (1982). Mowing Height (cm) no mow 2.5 5.0 no mow 2.5 5.0 Simazine (lb a.i./1000 ft¿) 0.0 0.0 0.0 2.0 2.0 2.0 LSD (0.05) Texoka Common Sharp's 1.5 3.0 3.0 2.5 5.0 6.5 1.0 2.5 3.5 2.0 4.0 4.5 1.0 3.0 4.0 2.0 4.0 6.5 1.0 0.5 0.5 * 82 Direct Low Temperature Damage of Bentgrass by Linda Bartelson and Nick Christians Winterkill is a comprehensive term that includes all types of injury to turfgrasses that occur during the winter season. The three major types of winterkill are direct low temperature kill, winter desiccation, and low temperature fungal diseases. Past research indicates that cultural factors which stimulate growth and cause a reduction in hardiness can result in an increase of low temperature kill. These factors include excessive nitrogen, a deficiency of potassium, a close mowing height, and inadequate soil drainage. Soil temperature seems to be a more critical factor in low temperature stress than the air temperature. When temperatures become sufficiently low, direct low temperature kill occurs. The damage may involve ice crystal formation within the cell or between the cells. Freezing within the cell usually results in the explosive growth of ice crystals in tissues that are full of water (hydrated). These large ice crystals disrupt and damage the cellular contents and membranes, leading to the eventual death of the tissue. Ice formation between cells may or may not damage the cells. This is more of an equilibrium process in which water is redistributed from within the cells to outer regions because of the lower vapor pressure of the ice between cells. As this dehydration continues, the cell becomes brittle and is subjected to extreme tensions during contraction which can result in damage. In this study, the effect of direct low temperatures on five creeping bentgrass cultivars (Emerald, 83 Penncross, Penneagle, Prominent, Seaside) and one velvet bentgrass cultivar (Kingstown) was investigated to determine the relative tolerance of the cultivars. The bentgrass cultivars were established in September 1980 and were maintained under three fertility levels: ft^/growing month 0.5, 0.8, and 1.2 lbs N/1000 (3.5, 5.6, and 8.4 lbs N/1000 ft^/year). In November 1981, plugs measuring 2.5 inches in diameter by 3 inches deep were taken from each cultivar and fertility treatment. They remained outside under snow cover until February when they were brought in and held at 0°C (32°F). The plugs were placed in a cold chamber and removed at 0, -8, -16, -24, -32, and -40°C. They were then potted and regrown in the greenhouse. All the bentgrass cultivars were at least somewhat tolerant to the lowest temperature treatment of -40°C (Fig. 1). were completely killed. None of the plugs In this study the relative degree of kill between cultivars is of more importance than the actual percent kill value because the actual kill value will vary due to year to year differences in many environmental factors such as: the rate of freezing, rate of thawing, number of times frozen, length of time frozen, tissue hydration level, and post-thawing treatment. After comparing the clipping weights of regrowth and percent kill values, Penneagle appeared to be least damaged by cold temperatures followed by Penncross, Prominent, and Emerald. Kingstown and Seaside were severely damaged with approximately 90Í of the plants being killed at -40°C (Fig. 2 and 3). The different fertility levels had no significant effect on the cold temperature tolerance of the cultivars. 2 Initially, the 1.2 lbs N/1000 ft /growing month fertility level showed 84 the most shoot regrowth (Fig. M), but after 35 days shoot regrowth was the same between fertility levels (Fig. 5). The lack of difference after 35 days can be attributed to a decrease in available N in the soil plugs. No additional fertilizer was applied during regrowth in the greenhouse. Conclusions Based on this study, Penneagle was the most low temperature tolerant of the bentgrass cultivars tested. It sustained the least visual damage, recovered faster, and had the most shoot regrowth. Penncross, Prominent, and Emerald were also relatively tolerant of low temperatures. However, Seaside and Kingstown showed a limited tolerance and probably would not perform as well in Iowa under severe winter temperatures. It is also interesting to note that there was no difference in survival between the fertility levels. However, as fertility increased, the recovery rate and amount of shoot regrowth increased. 85 Temperature °C CLIPPING WEIGHTS swBjg 87 Figure 2: Days After Treatment Clipping weights over all temperature treatments and fertility levels. Figure 3: Percent kill over all fertility levels. % K IL L - -4QQC Days A fte r Treatment C u ltiva r 10 15 25 35 Emerald Kingstown 77 84 73 82 Penncross Penneagle Praninent Seaside 79 87 71 59 74 93 69 55 73 90 64 52 69 89 67 78 52 38 63 LSD 11 11 10 5% 86 8 1 88 89 Figure 4: Kg N/lOOnr/m onth CLIPPING WEIGHT-15 Days Clipping weights over all temperature treatments. Figure 5: Clipping weights over all cultivars and temperature treatments. CD CO CD LO CVJ SLUBJ0 90 Phosphorus Fertilization Study by J. L. Nus and N. E. Christians The phosphorus (P) fertilization study was initiated in April 1981 to test the response of Kentucky bluegrass to increasing levels of P on a typical Iowa soil. The study is located on Section V, Block I of the ISU turf plots on the ISU Horticulture Research Station. The area was seeded with 'Baron* Kentucky bluegrass in September, 1979. establishment, At the time of 1.0 lb P_0.. (as triple super phosphate) and 0.5 lb N £ 5 per 1000 sq ft (as ammonium nitrate) were applied. The area used for the phosphorus fertilization has been maintained in lawn condition including two inch mowing, pre- and postemergent weed control, and standard fertilization with urea. been applied to the area. No insecticides or fungicides have Initial soil test levels of P on this area were 27 lb/A. The study was designed in a randomized complete block with six treatments and three replications. ^ 2 ® 5 Per and 12 lb Treatments included 0, 1, 2, 4, 8, 1000 SQ ft. Phosphorus was applied as triple super phosphate once per season in approximately the middle of May. Data was taken for spring greenup, average weekly clipping weight, and quality. consisted of a rating Spring greenup was taken in early May and from 0 to 9, with representing dark green turf. 0 = dead turf and 9 Clipping weight was recorded as the oven dry weight (in grams) of total clippings from a 1 X 2 meter plot. Quality was recorded as a number from 0 to 9, with 6.0 representing acceptable turf. Both spring green up and quality ratings were 91 estimated to the nearest decimal place. Table 40 shows the results of the Phosphorus Fertilization Study for 1982. The data can be summarized in one sentence: benefit in spring greenup, clipping yield, or no consistent turf quality was realized by fertilizing with phosphorus on these central Iowa soils. This investigation is a very long term study which will be maintained for several years on the same location. Soil tests, to determine P levels in the soil of each plot, will be taken in 1983 to record the progress of the study. 92 Overall Quality Oct Quality o• o• o• 00• vO 00• vO CO 525 00 m CO S5 vO vO CO S5 CM rH r—1 rH VO vO vO vO OV m • vO • vO O• G\ • vO vO m m in co • • vO • vO • vO • vO • VO CO• vO CO rH • CM • CNI • CM • CM • o• CO CO • Greenup Rating Ave. Weekly Clipping Wt. May Quality Aug Quality • July Quality • • June Quality Sept Quality o• • • $Z5 • !23 00 m • CO • 00 r^* o iH • co 1— 1 O >> 4-) ‘H t— 1 cO 2 O' to 4J +J -H O rH O cd P O' m . i"- m ON o\ CN vD vO • • • • O in u u P-, -H m m o CN v£> v£> o • • • in u 00 -H 3 rH < cd 2 O' in in h r— 1 *H 2 rH o cd o> • v£> CO rH • • • n- n- n- rH o> v£) vO 00 r^. • m • co r- o in CD 4-> C -H 2 rH *-i cd v£> • — f r» m 00 CO r>* r^ m o o> • • o in 4-) in *H cd tH a ^ — p< rH • 00 00 • ON • o> • 00 m CN o o in • r—1 4H 0) 0) 00 & c •H • P-t CD Pl , > -H <3 r-H u M & CU 00 2 c P *H CD 4 -> • in CN rH CD Cd H pc; O • CN m • m m• m • t—1 rH vX5 o vO vO NT o o o CN • o /T-N 4H c in o CD B 4 J cd CD H H + a P-. + a 0) Pm + a c cd •H rH O Pm rH CO a + a o U U a o u 96 o Q hJ CO N X K Study by J. L. Nus and N. E. Christians The nitrogen x potassium interaction study was initiated to observe the effects of nitrogen (N) and potassium (K) on the growth and development of 'Baron* Kentucky bluegrass and to evaluate the interactions between these two nutrients. The study is located in Section V, Block 1 of the ISU turf plots at the ISU Horticultural Research Station. 'Baron' Kent u c k y The area was seeded with bluegrass in September, 1979. At the time of establishment, 1.0 lb P^O^. Per -*-000 sq ft (as triple super phosphate) and 0.5 lb N per 1000 sq ft (as ammonium nitrate) were applied. The area used for the N X K interaction study has been maintained in lawn condition including two inch mowing, pre- and postemergent weed control, and standard fertilization with urea. No insecticides or fungicides have been applied to the area. The study is arranged as a complete factorial with four levels of N (0, 1.0, 1.5, and 2.0 kg/are/year) and four levels of K (0, 1.0, 1.5, and 2.0 kg/are/year). (One kg/are/year equals approximately 2 lb per 1000 sq ft per year.) A randomized complete block design is used for the 16 treatments and 3 reps. the source of K. Urea is the N source, and KC1 is Treatments began in April, 1981. Data were taken for spring greenup, average weekly clipping weight, and quality. Spring greenup was evaluated in early May and consisted of a rating from 9-0, 0=dead turf and 9 representing dark green turf. Clipping weight was recorded as the oven dry weight (in 97 grams) of total clippings from a 1 x 2 meter plot. Quality was recorded as a number from 9-0, with 6.0 representing acceptable turf. Both spring greenup and quality ratings were estimated to the nearest decimal place. The effects of N and K on quality and clipping weight are shown in tables 42 and 43. Both N and K increased quality ratings with increasing application rates. quality. Nitrogen had the greatest effect on There was an increase in quality on plots receiving 1 kg 2 K/are/yr (approx. 2 lbs/1000 ft ) over plots receiving no K; however, higher rates of K had little effect. Clipping weights increased with each increment of N, as would be expected. Potassium increased growth of Kentucky bluegrass up to the highest level of application, although the size of the response is much less than for N. Notice that most of the increase occurred between 0 and 1 kg/are/yr. The K soil test level on this area was 218 lb/A at initiation of treatments. The application of additional potassium on soils in this soil test range would be recommended. The only observable effects on spring greenup was from increasing rates of N; K had no effect. The greenup data is not included in the report. 98 Table 42. The effect of N and K on the quality ratings for Baron Kentucky bluegrass. K (kg/are/yr) N (kg/are/yr) 0.0 1.0 1.5 2.0 0.0 5.1 6.4 6.8 6.7 1.0 7.0 7.4 7.1 7.4 1.5 7.2 7.5 7.4 7.6 2.0 7.2 7.5 7.4 7.6 LSD for comparison of K levels = 0.2 LSD for comparison of N levels = 0.2 Table 43. The effect of N and K on the clipping weight of Baron Kentucky bluegrass. K (kg/are/yr) N (kg/are/yr) 0.0 1.0 1.5 2.0 0.0 5.7 12.3 17.0 21.7 o • 1 —1 22.7 37.7 34.7 38.7 1.5 27.0 41.7 41.0 52.3 2.0 42.0 48.7 52.7 55.0 LSD for comparison of K levels = 8.0 LSD for comparison of N levels = 8.0 99 Postemergent Herbicide Rate Study - 1982 by Sally Johnson The postemergent herbicide rate study was initiated in June, 1982. The material used was Trimec. herbicide that is a c o m bination Trimec is a post-emergent of 2,4-D, M C P P , and dicamba. Treatments were applied with the Spreader King liquid lawn care applicator at rates varying from 1/8 to 1 1/2 times the recommended rate of active ingredient. The purpose of the study was to see if the small droplet size emitted from the sprayer, combined with better overall coverage, would give more efficient herbicide action. The study was located in a weed-infested lawn area south of University Village at Iowa State University. The grass species in the area were primarily bluegrass and tall fescue. Trimec was mixed with enough water for 1 gallon to cover 8000 sq. ft. Broadleaf weeds present at the time of application included dandelion, plantain, white clover, yarrow, and bird's foot trefoil. A randomized complete block design including 3 replications and 7 treatments was used. Table 44. % Effectiveness of Trimec at different rates. of recommended rate applied 0.0 12.5 25.0 50.0 75.0 100.0 150.0 Weeds/m2 160 68 71 34 25 7 4 100 Effectiveness Very poor Very poor Fair-very poor Good-poor Good-fair Very good-good Very good Results were obtained by randomly counting the number of weeds in three subsamples of each test plot. A visual rating of the entire plot was made to correlate outward appearance of weed control with the actual number of weeds counted. All rates showed some weed control when compared to the nontreated plot, but this control was not very good until at least the recommended rate was applied. 50% of Although the weed number for 50% and 75i of the recommended rate was high, the overall appearance of these plots was fairly good. The more obnoxious looking weeds, such as dandelion, were removed, although other broadleafed types remained. Preliminary results indicate that lower rates of Trimec may indeed give adequate broadleaf weed control when applied with the Spreader King, or a controlled droplet size-applicator. will need to be done to document these findings. 101 Further work Fall Topdressing Investigation The fall topdressing study was begun in November of 1980. The results of the first 2 years were discussed in the 1981 and 1982 field day reports. This investigation is being conducted on Penncross creeping bentgrass, established on both a native soil and a modified soil. Three different treatments were included; a) a 70-10-20 (sand- soil-peat) mix, b) a 1-1-1 topdressing mix, and c) a control area where no topdressing was applied. depth of 1/4 inch. The treatments were applied at a Each topdressing treatment was further divided into 3 fertilizer treatments that were applied just prior to topdressing; a) no nitrogen, b) 0.5 lb N/1000 sq ft, and c) 1 lb N/1000 sq ft. The treatments applied to the native soil area were exactly the same as those applied to the modified soil. The 1980-1981 winter was very dry and mild. The topdressing treatments proved to be very beneficial under these conditions, with topdressed areas showing less winter damage and a much improved spring greenup. The 1981-1982 winter was very cold and the area was covered by snow from December to March. Under these conditions, there was little difference between topdressed and control areas. The 1982-1983 winter was again somewhat mild and the plot area was not covered by snow through most of the winter. As was the case in the spring of 1981, the topdressed areas greened up much earlier than did the untreated areas (Table 45). By March 3, 1983, the areas topdressed with the 1-1-1 topdressing had attained an acceptable color rating of 6.0 on both native and modified soils. 102 Control areas did not reach a satisfactory rating until 51 days later, on April 23. The late winter of 1983 was very mild, with unseasonably warm temperatures recorded in late February and early March. These early, warm conditions were followed by cold temperatures in mid-March and early April, and by heavy snowfall. observed on the treated areas. No detrimental effects were Following the early spring snow storms, it was expected that snow mold might develop on treated areas because of the lack of fungicide treatments. No serious snow mold problems were observed. The application of nitrogen just prior to topdressing improved color ratings for each of the topdressing treatments (Table 46). This dormant application of urea has proven to be beneficial in 2 of the last 3 seasons. The fall topdressing investigation will be continued for several seasons. Table 45. Color ratings for the modified (1-1-1) soil green and the native soil green in the spring of 1982. Date Treatment Mar 3 Mar 25 Mar 13 Apr 15 Apr 23 Mean Modified Soil Control 70-10-20 1-1-1 2.5 5.5 6.0 3.0 6.0 6.5 2.5 5.0 5.5 3.5 6.0 6.0 6.0 7.5 8.0 3.5 6.0 6.5 Native Soil Control 70-10-20 1-1-1 2.0 5.0 6.0 2.5 6.0 6.5 2.5 5.5 5.5 4.0 6.5 6.0 6.3 8.0 8.0 3.5 5.5 6.0 Color is rated on a scale of 9 - 1, where 9 = complete recovery after winter dormancy and 1 = dormant turf. 103 Table 46. Color ratings for the modified (1-1-1) soil green and the native soil green as affected by fertilizer rate. Topdressing Treatment Control Soil 70-10-20 1-1-1 0* 0.5 1.0 0 0.5 1.0 0 0.5 1.0 Modified 2.5** 3.5 4.0 5.5 6.0 6.5 6.0 6.5 6.5 Native 3.0 3.5 4.5 6.0 6.5 7.0 6.0 6.5 6.5 * Pounds N/1000 sq ft applied just prior to topdressing treatments. ** 9 = total recovery, 1 = dormant turf, values listed are the means of the 4 rating dates. 104 The Effects of Growth Retardants on Three Turfgrass Species Nick Christians and James Nau In the winter of 1981-1982 a greenhouse study was performed to evaluate the effects turfgrass species. of a number of growth retardants on three ’Baron' Kentucky bluegrass (Poa pratensis L.), 'Kentucky 31' tall fescue (Festuca arundinacea Schreb.), and 'Reliant' hard fescue (Festuca ovina var. duriuscula L. Koch.) were treated with three growth retardants: N- [2,4-dimethyl-5- [[(trif luromethyl) sulfonyl]amino]phenyl]acetamide (MBR 12325) at 0.25 and 0.50 lb/acre; [2-chloroethyl]-phosphonic acid (ethephon) at 2.0, 4.0, and 6.7 lb/acre; and 5-(4-chlorophenyl )-3,4,5,9,10-pentaaza-te tracyclo [5,4,1,02 , 6 ,08,11 ] dodeca-3,9-diene (BAS 106 00 W) at 1.5, 3.0, and 4.5 lb/acre. Data collected on a weekly basis included oven-dry clipping weights and quality ratings based primarily on color, uniformity, and density and rated on a scale of 9-1 (9 highest quality, and 1, dead turf). The study was maintained for six weeks after visible response began. At termination, data were collected on root weight, which was based on the difference between oven-dry and ash weights. Where appropriate, data also were taken on rhizome number per pot, on rhizome length, and on the oven-dry weight of rhizomes. For purposes of verification, the study was repeated in the same way in the spring of 1982. Samples from the same location were established on March 18, 1982, and treatments were initiated on April 24, 1982. Data from the combined investigations were statistically analyzed to measure the variability between studies. 105 Where no significant differences were found between studies (p=0.01), the data were combined for analysis. Only data verified in this way are discussed. Results and Discussion MBR 12325 (0.25 and 0.50 lb/acre) was effective in reducing the clipping yield of each species (Fig. 1). The figures were prepared for scientific publication and treatments are listed in kg/ha. kg/ha is equal to .89 lb/acre. One The degree of inhibition was very similar for Kentucky bluegrass and hard fescue, with reductions in yield ranging from 17 to 39% • There was a reduction in growth of tall fescue, but to a lesser degree than for the other two species with growth being reduced approximately 10%. The BAS 106 00 W (1.50, 3-00, and 4.50 lb/acre) also was effective in reducing growth of all three species. The Kentucky bluegrass and hard fescue responded in a similar way to the additions of this material, with reductions in clipping yield ranging from 41 to 74%. inhibited to a lesser extent. species. For Again, the tall fescue was The effects of ethephon varied with Kentucky bluegrass, there was a 28% reduction in clipping yield at the 2.0 kg/ha rate. There was less inhibition as the rate of ethephon was increased. Turfgrass quality was reduced by MBR 12325 (0.25 and 0.50 lb/acre) and BAS 106 00 W (2.0, 4.0, and 6.0 lb/acre) to a similar degree for each of the species (Fig. 2). are interpreted as unacceptable treatments were unacceptable, Reductions in excess of 15% phy totoxici t y . Although some there was no severe phytotoxicity observed with any of the materials. 106 There was considerable variability in root weight data for tall fescue and hard fescue, but repeatable results were obtained for Kentucky bluegrass (Fig. 3). MBR 12325 (0.25 and 0.50 kg/ha) reduced root weights from 19 to 2656 for bluegrass, whereas the BAS 106 00 W had no inhibitory effect on root weights. There was a 24/6 increase in root weight in response to ethephon (2.0 lb/acre) and decreases of 13 and 2156 in response to the 4.0- and 6.0-lb/acre rates, respectively. The results of the study indicate that polystands of Kentucky bluegrass and hard fescue could be expected to respond in a fairly similar way to MBR 12325, BAS 106 00 W, and to the 2.0 lb/acre rate of ethephon. However, where tall fescue is included in the polystand, as is often the case in the northern U.S., variations in response can be expected. 107 CD D u CO CLIPPING WEIGHT 0) fc? o 0 D II u V T T l'"l l J a CO • ••«•••I o ¿ ■ * 1 i*i*i*ii 0 u. o o JO 00 SO Q \ c s CO m f f d o 00 o O CO o • r— ^ 00 CN CN K • • C O *-0 C N O ’ CO CO V D C 0 o G> 0 _D 00 L O CO 0 2 00 U •H Pm O O CN — O O i o CO o o o o o CS m I I o o i: k? o K J 108 I I to o _ 1 1 l 1__L 1 1 1 1 J o O o o if) O o CO o CN o o o1 O CN C O uoi 1 1 1 n u- o u no Sod Reestablishment Study by Tom Robeson On May 12, 1981, a Kentucky bluegrass sod was cut and removed from section 3 at the Research Station. reestablishment treatments were applied. were: Then, on May 14, the The purposes of this study a) to evaluate reestablishment of Kentucky bluegrass after sod harvest, and b) to observe the effects of applying phosphorus fertilizer on sod plot reestablishment. The Five Methods of Reestablishment 1. Control (sod removed with no further treatment) 2. Spiking 3. Tilling followed by reseeding at 3/4 lb seed per 1000 sq ft 4. Overseeding at 3/8 lb seed per 1000 sq ft 5. Overseeding at 3/4 lb seed per 1000 sq ft Each of these plots was split in half. surface, To one half of the plot phosphorus fertilizer was applied at 1 lb P per 1000 sq ft. No P was applied to the other half. Percent turfgrass cover was measured once a month until plots were completely covered. Sod strength measurements were collected after 16 months. The results indicate that after 16 months none of the reestablishment treatments showed a significantly higher percent cover or sod strength over the control (Table 47). The phosphorus fertilizer treatment did improve percent cover, but not sod strength (Table 48). Ill Further evaluation of the effects of phosphorus fertilization on reestablishment indicate that most of the increase in cover occurred in the plots treated by spiking (Table 49). The purpose of this treatment is to sever rhizomes and thereby to increase regrowth. Surface-applied phosphorus appears to be quite important where this procedure is used. Table 47. Effects of treatments on percent cover and sod strength. Treatment Percent Cover Control Spiking 3/8 lb/1000 sq ft 3/4 lb/1000 sq ft Rototilled LSD 0.05 Table 48. Sod Strength 93 86 94 90 93 58 59 6 14 62 57 52 Phosphorus fertilizer test results. Treatment Percent Cover Phosphorus Applied Phosphorus Not Applied Sod Strength 60 56 95 87 LSD 0.05 N.S. Table 49. Interaction of reestablishment treatment and phosphorus application. Treatment Control Spiking 3/8 lb/ 1000 sq ft ■% Phosphorus Applied Phosphorus Not Applied LSD 0.05 3/4 lb/ 1000 sq ft Tilling + cover- 93 96 93 92 99 93 76 93 86 86 9 (for the comparison of treatments) *Sod strength is measured in lbs of force required to break sod. 112 Sod Production by Tom Robeson This sod production study was established in August, 1980, at the Ames Research Station with the final sod strength measurement taken in September, 1982. The objectives of this study were: a) to compare sod producing characteristics of five different cultivars of Kentucky bluegrass and b) to measure the effects of surface-applied vs. incorporated phosphorus fertilization on seedling establishment and root rhizome development. The five cultivars tested were: Parade, Ram I, Rugby, and Touchdown. Glade, The cultivar plots were further split into incorporated and surface-applied treatments. One half receives 1 lb phosphorus per 1000 sq ft applied to the seedbed surface. The other half received 1 lb phosphorus per 1000 sq ft incorporated into the seedbed to a depth of approximately three inches. Percent cover measurements were collected monthly and sod strength measurements were taken at the end of the second growing season. Conclusions The five cultivars tested varied in percent cover, with Rugby exhibiting the highest percent cover and Ram I the lowest based on average rating over the two seasons (Table 50). Sod strength was not significantly different among cultivars or between fertilization treatments. Percent cover was significantly higher for the plots which received a surface application of phosphorus (Table 51). Final results from this investigation will be available by August, 1983. 113 Table 50. Cultivar differences in percent cover and sod strength Cultivar Glade Parade Ram I Rugby Touchdown LSD 0.05 Percent Cover 47 50 38 53 47 7 Sod Strength 87 79 80 85 83 N.S. Table 51. The effects of fertilizer placement on percent cover and sod strength. Fertilizer Surface Applied Incorporated LSD 0.05 Percent Cover 50 44 5 114 Sod Strength 84 82 N.S. Pythium - Induced Root Dysfunction of Creeping Bentgrass on High Sand Content Mixes by Clinton F. Hodges The potential importance of Pythium species as root-infecting pathogens of creeping bentgrass is not clear. Pythium species are known to be associated with the roots of creeping bentgrass and are known to infect seedling roots of this species. Where Pythium species are associated with the roots of turfgrass symptoms of slow growth, off-color, and thinning may occur. Some species of Pythium have been shown to cause extensive root rotting in turfgrass during periods of hot weather. A disease of unknown origin, but typical of cottony blight in appearance, destroyed several golf greens in Central Iowa during the midsummer heat and high humidity of 1977. Only greens newly renovated to a high sand content mix (80% sand) were affected by the disease. The greens were entirely killed within a period of 10 days. to isolate Pythium from leaf and stem tissue failed. however, consistently yielded Pythium species. interest that the Attempts Root isolations, It is of special Pythium-infected roots were not rooted. All infected root tissues were intact and showed only a mild yellow-tan discoloration and rarely a surface lesion. Similar root symptoms have been attributed to Pythium infection of cereals. Since the original observation of this Pythium-induced root disorder of creeping bentgrass in 1977, the problem has been identified from creeping bentgrass greens as far north as Ontario, Canada, and as far south as Georgia. 115 To date, six Pythium isolates have been acquired and at least three of them appear to be pathogenic on the basis of preliminary studies. In all instances, the disease has occurred only on high sand content greens and appears to be most serious on old golf courses where the greens have been renovated to sand. The occurence of this disease only on high sand content greens is significant both economically and biologically. The present trend of using pure or high sand content mixes for golf green construction and renovation is growing in popularity. The construction of a golf green is a long term investment; in the case of sand greens, it also implies several changes in management practices. Unfortunately, the biological ramifications of the use of sand and the management changes necessary to grow grass on sand require some time to occur. o b s ervations to date Our on the Pythium root disorder of creeping bentgrass grown in sand is suggestive of a disease that exists only in sand and with the management practices necessary for maintenance of sand greens. It is probable that one of the primary factors responsible for this problem is an incomplete microbiology of the sand medium. Inadequate microbiological competition may permit Pythium species to induce disease in sand and not in soil. some Other factors contributing to the problem may include fertilization and irrigation practices on sand greens, and c o n d itions of high temperatures and humidity. Present research p a t h o g enicity is c o n c e r n e d with the indentity and of the Pythium isolates, and with disease-stress interactions. 116 SELECTIVE CONTROL OF TALL FESCUE IN KENTUCKY BLUEGRASS WITH CHLORSULFURON by Dorothy Larocque and Nick Christians Abstract Kentucky bluegrass, Poa pratensis, L. cv. Baron, and tall fescue, Festuca arundinacea Schreb. cv. Kentucky 31 were treated with single applications of 2 chloro-N aminocarbonyl) (4-raethoxy-6 methyl-1,3,5-triazon-2-yl benzenesulfonamide, (Chlorsulf uron) at the rate of 0.25, 0.50, 1.0, 2.0, 3*0, 4.0 oz./A and with split application rates of 0.25 + 0.25, 0.50 + 0.50, 1.0 + 1.0, 2.0 + 2.0, and 3.0 + 3*0 oz/A applied at two-week interval. weekly dry clipping weights, development were observed Data taken during the study included; quality ratings. and measured Root and rhizome at termination. The chlorsulfuron severely damaged the tall fescue at single application rates of 0.50 oz/A and split application rates of 0.50 + 0.50 oz/A and greater. The Kentucky bluegrass showed a much higher tolerance to the chlorsulfuron with little effect at the 4.0 oz/A single application rate and only minor damage at the 3.0 + 3.0 oz/A split application rate. Introduction Tall fescue is a common weed problem in Kentucky bluegrass. It is a major problem because of the incompatibilities between the two species and the lack of a selective control for the tall fescue. Kentucky bluegrass, Poa pratensis L. cv. Baron is the predominant cool season grass in the U.S. It is used on golf courses, lawns, and 117 other recreational areas. It has a medium texture and dark green color, and forms an attractive turfgrass with the ability to spread and grow by rhizomes and tillers. It also forms a tightly knit turf, which is a most desirable turfgrass characteristic. Tall fescue, Festuca arundinacea Schreb. cv. Kentucky 31, is also a cool season grass; however, it is better adapted to the hot, dry climate of the transitional zone states, such as western Nebraska and Kansas. It is used mainly on athletic fields due to its tolerance and resistance to heavy traffic. It has a bunch-type growth habit with deep roots enabling it to withstand drought and to penetrate hard, compacted clay soils. However, due to its wide, coarse-textured leaf blades and bunch-type growth habit, the grass will disrupt the uniformity of Kentucky bluegrass and become a serious weed problem. The objectives of this study were to determine (1) the effects of chlorsulfuron on the two species and (2) to establish the tolerance levels for the species to this chemical. Fifty sod plugs of Kentucky bluegrass (Poa pratensis) and tall fescue (Festuca arundinacea) were collected from the ISU Horticulture Research Station turf plots. The plugs were potted in 8" pots with field soil and placed in a randomized complete block design with four replications. inches and They were maintained at 70°F, cut at the heights of 2 2.5 inches (Kentucky bluegrass and tall fescue, respectively) and fertilized every 2 weeks with a 20-20-20 fertilizer prior to application. 118 Table 52. Set-up of the randomized complete block design with M replications for the greenhquse experiment. T a l l Fescue Co y- / 9 tj~ n t s TeeArm£VTS> - oi/a /. C O N T R O L 7 G L E VO or./A 0. G L E A N o a 3 ¿.LEAN o. 5 0o z j A V /o o z/A /« G L E A N Jo + 1.0 or./A 5. G L E A Jo o z/A II. G L E A N J O t o o oz./A U 30 •Z/A U. G L E A N So + 5.0 oz/A G L E A N G L E A N ^ o z Ja l O J S + oo5* o r / A G L E A N 4 g l e 0 S O + O.SO or] A \ i The chemical applied was chlorsulfuron, 2-chloro-N methyl-1, (Glean). 3, 5-triazon-2-yl aminocarbonyl) (4-methoxy-6- benzenesulfonamide , It is a white, odorless, crystalline solid, slightly soluble in methylene chloride, acetone, methanol, and water (depending on pH). It was developed by the DuPont Company for the control of broad-leaf weeds in wheat and barley fields; however, selectivity for the control of tall fescue. it has shown some It is a systemic and active through both the foliage and root system. All seven chlorsulfuron treatments were applied on the same day in January '83 with the split applications applied after a 2 week interval (Table 52). used to insure An atomizer attached to an air pressure pump was uniform coverage during application. During application, each plug was shielded to eliminate drift, then sprayed with 2 milliliters of the proper chlorsulfuron treatment. 119 The weekly clippings were dried and weighed to determine the amount of growth occuring at each treatment rate. The weekly quality ratings were determined on a scale from 9 to 1, 9 being best quality and 1 being dead turf. Root and rhizome development were determined by a drying and ashing procedure at termination. Table 53» C h l o r s u l f u r o n treatment rates for single and split applications expressed in kg/ha and ounces acre. TREATMENTS SI NGLE kg/ha 1 2 3 4 5 6 7 CONTROL 0 .0 1 8 0.035 0.071 0 .1 4 1 0.212 0 .2 8 2 REFE AT k g /h a oz/A oi/X 0 .2 5 0 .5 0 1.0 2 .0 3.0 4 .0 8 9 0.035 0.071 0 .5 0 1.0 10 11 12 0.141 0.282 0.424 2 .0 4 .0 6.0 Results The responses varied with species and treatment rates. The Kentucky bluegrass showed a much higher tolerance to the chemical, with only minor damage at the highest split application rate of 3.0 + 3.0 oz/A. However, the tall fescue displayed such symptoms as: growth retardation, chlorosis, and necrosis at the 0.50 + 0.50 oz/A split application rate with increasing damage at increased rates. (Fig. 2 and 3) show percent kill and turf quality respectively. 120 Fig. 2. The relationship between the increasing chlorsulfuron treatment rates and % kill for each species. The decrease in turf quality with increasing chlorsulfuron Q U A LIT Y R A T IN O S Fig. 3. rates. C N LO R S U LFU R O N (h f/fc *) •All treatments are listed in kilograms per hectare. The treatments are equal to the following rates in ounces. 1/4, 1/2, 1, 2, 3, 4 oz/A single applications (left), and 1/2, 1, 2, 4, 6 oz/A split applications (right) . 121 Conclusion The Kentucky bluegrass showed a much higher tolerance to the chlorsulfuron than the tall fescue. The tall fescue was effected greatly by the chlorsulfuron, showing very low tolerance to the chemical. The tall fescue was effected at all rates above 0.25 oz/A with the most damage done at the rate of 0.50 oz/A and above. The data from this study show that chlorsulfuron has potential for being a selective control for tall fescue in Kentucky bluegrass. However, the study will be repeated in the greenhouse and then conducted under field conditions to substantiate these conclusions. 122 h \ ÄEPA United State« Environmental Protection Agency M unicipal Environmental Research Laboratory Cincinnati OH 45268 Research and Development E P A -6 0 0 /S 2 -8 1 -074 May 1981 Project Sum m ary Safe Disposal Methods for Agricultural Pesticide Wastes C harles V. Hall, Jam es Baker, Paul Dahm , Loras Freiburger, Greg Gorder, Layne Johnson, Gregor Junk, Fred W illiam s, and Charles J. Rogers During the 3-year period from October 1976 to 1979, comprehen­ sive chemical, biological, climatolog­ ical, and engineering studies were conducted at Iowa State University, Ames, Iowa, to determine effective­ ness of pesticide disposal facilities being used at the school and to com­ pare controlled systems that might provide a basis for improvement. Evaluation of the pit disposal systems included detailed chemical sampling of the systems and their surrounding environments, identification and counts of bacterial populations, ento­ mological studies, estimation of pesticide volatilization rates, and evaluation of pit design for efficiency, effectiveness, and convenience of operation. This Project S u m m a ry was develop­ ed by ER A 's M u n ic ip a l E n viro nm en tal Research Laboratory, C incinnati, O H, to announce key findings o f the research p ro je ct th at is fully docu­ m e n te d in a separate report o f the sam e title {see Project R ep o rt ordering info rm ation at back). introduction A polyethylene-lined open pit at the A g ro n o m y -A g ric u ltu ra l Engineering Research Center had been used for dumping surplus dilute pesticides, prim arily herbicides, for about 14 years. In 1978, a new pit was built; it was lined w ith tw o layers of 6-m l-thick polyethyl­* ene plastic; filled w ith sand, soil, and gravel; and covered by a metal building. Sampling w ells were installed for m oni­ toring purposes. To test pit disposal methods under controlled conditions, 56 polyethylene m inipits, each w ith a capacity of 11 5 liters and equipped w ith a cover, were installed partially underground. Com­ binations of four herbicides (alachlor, atrazine, triflu ra lin , and 2,4-D) and two insecticides (carbaryl and parathion) were studied in mixtures and individ­ ually at tw o concentrations after being incorporated w ith 1 5 kg of soil and 55 liters of water per container. One half of the containers were aerated. For each combination of pesticide, chemical dissipation, bacterial activity, and bio­ assays were conducted. A concrete pesticide disposal pit at the Horticulture Station, in operation s in c e 1 9 7 0 , w a s s y s te m a tic a lly monitored, and the chemical disposal, accumulation, bacterial activity, and evaporation were evaluated. The inside pit dimensions are 3.35 m (width) x 8.84 m (length) x 1 m (depth). It is filled w ith soil and gravel layers each approxi­ mately 30 cm thick. A motorized cover triggered by rainfall closes to prevent flooding. Climatological data were col­ lected on the site and correlated w ith pan and pit evaporation. Programs were developed to predict pit evaporation rates from local evaporation data. Leak­ age from the pit was monitored as well as pollution of a lakeand w ell located on the station. * U S. GOVERNMENT PRINTING OFFICE: 1 9 6 1 - 7 5 7 - 0 1 2 /7 1 3 3 123 Results A fter 14 years of dum ping dilute pesticides (prim arily herbicides) in the open, polyethylene-lined pit at the A g ro n o m y -A g ric u ltu ra I E n g in e e rin g Research Center, the surrounding area obviously had been affected. The pit was ineffective because it had overflow ed, rainfall had not been excluded, and the plastic had deteriorated. A large area, free of all vegetation, was cultivated, planted w ith corn, soybeans, and selec­ ted weed species. Only corn grew, w h ich indicated a high concentration of triazine compounds. The new ly constructed polyethylenelined pit covered w ith a metal building appears to have a seepage problem since the w ater level fluctuates. O bvi­ ously tw o 6 -m l-th ick layers of plastic are inadequate regardless of the care taken in installation. In areas w here the w a te r table is high or w here seepage w ill occur, sim ilar system s for disposal aré unsatisfactory. In colder clim ates, w here freezing and th a w in g of soil occurs to a considerable depth, pit liners m ust be selected w ith extrem e care. The reinforced concrete disposal pit at the H orticu lture S tation appears to be com pletely environm entally safe and effective for pesticide w aste disposal. Follow ing 10 years' use and the dispos­ al of over 40 diffe re n t pesticides (insec­ ticides, fungicides, herbicides, etc.), the system continues to fu n ctio n e fficie n tly and no leakage has occurred. A erobic bacterial activity in the soil is highly effective in biodegrading many of the compounds. Liquids continue to evapo­ rate w ith no detectable atm ospheric pollution. The rainfall-activa te d cover fu n ctio n s to prevent overflo w in g and excludes all outside w ater. Evaporation and clim atological data collected on the site w ere used to develop models for predicting evapora­ tio n at other geographic locations. D uring a norm al season, over 6,0 0 0 gallons of w a te r are evaporated from th is pit. A new cover design w as developed to reduce in itia l cost and re strict access to the disposal area. A ll pesticide sprayers being used have been m odified to perm it excess liquids to be dum ped into the pit w ith o u t th e equipm ent entering the pit. A fte r 68 weeks, of w h ich only about 30 w ere conducive to active pesticide decay, data collected fro m residues in the m icropits conta in in g the six selected pesticides w ere evaluated. The effect of aeration and n u trie n t supplem ents on decay rate and bacterial and insecticidal activity w ere measured. Those com ­ pounds most resistant to decay w ere atrazine, alachlor, and triflu ra lin ; they w ere, however, contained and did not co ntam inate surrounding areas. Complete m ethodology fo r all phases of research w ere developed and are described in the fin a l report. The fu ll report w as subm itted in fu l­ fillm e n t of G rant No. R -804533 by Iowa State U niversity under the sponsorship of th e U.S. E nvironm ental P rotection Agency. C h a r le s V. Hall. J a m e s B ak er, P a u l D ahm . L ora s F r eib u r g er , G r eg G ord er, L a y n e J o h n s o n , G r e g o r Ju n k , a n d F r ed W illiam s a r e w ith t h e I o w a S ta te U n iversity, A m es, IA 5 0 0 1 1 . C h a r le s J . R o g e r s is t h e EPA P r o je c t O ffic e r ( s e e b e lo w ) . T he c o m p l e t e r e p o r t, e n t i t l e d "S a fe D is p o sa l M e th o d s fo r A g r icu ltu r a l P e s t i c i d e W a s t e s ( O r d e r No. PB 81 -1 9 7 5 8 4 ; C ost: $ 1 8 .5 0 . s u b j e c t to c h a n g e ) w ill b e a v a ila b le o n ly fr o m : N a tion a l T e c h n ic a l I n fo r m a tio n S e r v i c e 5 2 8 5 P ort R o y a l R oa d S p r in g fie ld , VA 22 1 6 1 T e le p h o n e : 7 0 3 -4 8 7 -4 6 5 0 T he EPA P r o je c t O ffic e r c a n b e c o n t a c t e d a t: M u n icip a l E n v ir o n m e n ta l R e s e a r c h L a b o ra to ry U. S. E n v ir o n m e n ta l P r o t e c t io n A g e n c y C in cin n a ti, OH 4 5 2 6 8 124 SAFE DISPOSAL METHODS FOR AGRICULTURAL PESTICIDE WASTES SUMMARY OF RESULTS Following three years intensive research by scientists in the Ames Laboratory, the Departments of Agronomy, Agricultural Engineering, Bacteriology, Botany, Entomology and Horticulture and co-sponsored by USEPA, evaluating the effectiveness of various waste pesticide disposal systems, the results can be summarized as follows: (1) A concrete pit equipped with a rain activated mobile cover, filled with layers of gravel, soil and gravel, located at the Horticulture Station, was found to be a highly satisfactory disposal system. The pit which has a volume of approximately 30,000 liters has had over 50,000 grams of waste from over 40 pesticides deposited since 1970 and continues to be fully effective. (2) No leakage or contamination of the well, lake or other surrounding areas was found. (3) Bacterial populations continued to be effective in degradation of various compounds. (4) No harmful environmental effects were found. (5) A container cleaning and disposal system was established. (6) Computer models are being developed to predict evaporation based on climatological data collected on site. A film plastic lined pit constructed at the Agronomy-Agricultural Engineering Station was less effective in containing liquid pesticide wastes. effects of pit leakage were not determined. Prepared by: Charles V. Hall June, 1983 125 Environmental Shade Tree Mineral Nutrition Studies - Horticulture Research Farm This study was started in the fall of 1980 and terminated in the fall of 1982. Data from this study are presently being statistically analyzed and interpreted. Publication of the results is expected by late 1983 or early 1984. This study consisted of three experiments and a preliminary examination of correcting iron chlorosis in pin oak by soil application of various iron compounds and acids. One experiment examined fertilizing methods (drill hole, tree stake and water injection) on growth of three tree genera (pin oak, scotch pine, silver maple) and the incidence of Mgreen spotting" of the turf as affected by depth of fertilizer placement (shallow and deep), number of application points (X and 2X) and time of application (spring or fall). A second experiment examined type of nitrogen (Urea or Nitroform Bluechip) on growth of the same three tree genera as affected by placement zone (dripline or 3 ft. outside dripline), number of application points (X or 2X) ¿nd time of application (spring or fall). The third experiment examined tree stakes (Jobe’s or Ross Daniel) on growth of silver maple and scotch pine as affected by placement zone and application time. The preliminary pin oak iron chlorosis study revealed no visual benefit from soil application of iron sulfate, Ross Daniel "Green Again" injection, sulfuric acid or phosphoric acid. Wayne Hefley June, 1983 126 NATIVE GRASSES AND WILDFLOWER EVALUATION Native grass and wildflower plots were established in the fall of 1981. Fall plots were dormant seeded in early December 1981. Spring plots were seeded the last week in May 1982. Plots were prepared by 1) rototilling and a straw mulch applied after seeding; 2) spraying with Roundup and heavy verticutting or 3) spraying with Roundup and lightly verticutting. Seed was uniformly mixed, broadcast over 3 x 3 m plots, and worked into soil contact with a rake. One-half of each plot was fertilized with .5 lb nitrogen and 1.0 lb phosphorus/ 1000 square feet after seeding. Each treatment was replicated three times. The Pinto Northern Wildflower Mixture contained bachelor button, baby’s breath, chicory, evening primrose, scarlet flax, catchfly, clasping coneflower, lanceleafed coreopsis, corn poppy, baby snapdragon, and Lewis flax. The Pinto mix was planted as recommended, 4 pounds per acre wildflower seed plus 26 pounds per acre fine fescue (sheep fescue). The native grass and prairie flower plots were seeded with 9 pounds pure live seed per acre (pls/a) native grass and 2 ounces per acre of each native prairie flower. The native grass mixture consisted of Blackwell’s switchgrass (1 lb pls/a), Kaw big bluestem (2.5 lb pls/a), Blaze little bluestem (1.5 lb pls/a), Nebraska 54 indiangrass (2 lb pls/a), and Trailways sideoats grama (2 lb pls/a). Included with the grasses were 6 prairie flowers, Kaneb purple prairie clover, Sunglow gray-headed prairie coneflower, upright prairie coneflower, Eureka thick spike gayfeather, Nekan pitcher’s sage, and the purple coneflower. Results and Discussion The Pinto wildflower mix seeded in the fall produced the heaviest establishment the first season. A good succession of bloom from the annuals-biennials continued from early until late season. The late spring seeding produced very few blooming plants although many were present in a rosette stage. The rototilled plots produced the best establishment, growth, and blossoming the first season. The Roundup treatment with the heavy and light verticutting allowed some establishment but resulted in reduced growth and limited flowering. Fall seeding of the native grass and prairie flower mixture produced better establishment of the native prairie flowers. A few of the upright coneflowers (a shortlived perennial) bloomed the first season. Other recognizable prairie flowers seen included the purple coneflower, pitcher’s sage, the upright coneflower, and the gray-headed coneflower. In the fall seeded plots a few switchgrass seedlings were also identified. The late spring seeding of the native grass and prairie flower mixture appeared to aid the establishment of the grasses although a few native flowers were present. Rototilling resulted in heavier weed growth in those plots and we are unable to ascertain whether it aided in the establishment of the native grasses. Fertilization increased weed growth and did not, apparently, improve growth of the seeded species. The native grasses and selected native flowers are perennials and take one or two seasons to become established prior to producing seedheads and flowering. Evaluation this second season should indicate the degree of establishment of the native grasses. The native grasses are extremely difficult to detect and positively identify in their vegetative stage. 127 Evaluation of the Pinto Wildflower mix must continue a second season as well. Many of the species are annuals, biennials, or extremely shortlived perennials. Many must reseed themselves each year for continued flowering. Nearly all would need to reseed if season-long bloom is to occur. There appeared to be very little establishment of the fine leafed fescue. Evaluation the second season will determine longterm effectiveness of the Pinto Wildflower seed mixture. 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Allied Chemicals Agriculture Pro Division 9706 Mockingbird Dr. Omaha, NE 68103 CTL States Sales for Dupont Co. 1400 73rd Des Moines, IA 50311 The Andersons P.0. Box 119 Maumee, OH 43537 W.A. Cleary Corp. 1049 Somerset Street Somerset, NJ 08873 Ashland Chemical Co. Division of Ashland Oil Inc. P.0. Box 2219 Columbus, OH 43216 The Cyclone Seeder Co. Inc. Harrisburg, PA 17105 BASF Wyandotte Corp. 140 New Dutch Land Fairfield, NJ 07006 Diamond Shamrock 1100 Superior Avenue Cleveland, OH 44114 Big Bear Turf Equip. Co. 1840 Fuller Road West Des Moines, IA 50265 Dow Chemical 10890 Benson Shawnee Mission, KS Boots Hercules Agrochem. Co. BFC 10920 Ambassador Dr. Kansas City, M0 64153 Dupont Inc. 1007 Market St. Wilmington, DE Boots Hercules Agrochem. Inc. Louisiana, MO 63353 Eagle Green Corp. Omaha, NE 68103 Brayton Chemical P.0. Box 437 West Burlington, IA Elanco Products Co. P.0. Box 708 Greenfield, IN 46140 52655 19898 Britt Tech. Corp. P.0. Box 216 Britt, IA 50423 Eli Colby Company P.0. Box 248 Lake Mills, IA 50450 CIBA-Geigy Corp. Agriculture Division Greensboro, NC 27049 Hawkeye Chemical Co. P.0. Box 899 Clinton, IA 52732 130 66210 International Seeds 820 First St. P.0. Box 168 Halsey, OR 97348 Rain Bird Eastern Sales Corp. 1005 E 2nd St. Lees Summitt, MO 64063 Iowa Golf Course Superintendents Association Rhone-Poulenc Chemical Co. Black Horse Lane P.0. Box 125 Monmouth Junction, NJ 08852 Iowa Turfgrass Growers Association O.M. Scott & Sons Marysville, OH 43040 Iowa Turfgrass Institute Spraying Systems Co. N Ave. at Schmale Rd. Wheaton, IL 60187 Jackson Manufacturing Co. P.0. Box 1649 Harrisburg, PA 17105 Stutsman Co. Hills, IA 52235 Lakeshore Equip. & Supply Co. 300 S Abbe Road Elyria, OH 44035 Par Ex Swift Ag. Products Corp. 518 Pauline Dr. Buffalo Grove, IL 60090 Loft-Kellogg Seed P.0. Box 684 322 East Florida St. Milwaukee, WI 53201 3M Company St. Paul, MN M & A Enterprises 4346 S 90th Omaha, NE 68127 The Toro Co. Irrigation Div. 5825 Jasmine St. Riverside, CA 92504 Monsanto Ag. Products 800 N Lindbergh Blvd. St. Louis, MO 63166 Tri State Toro Co. 1951 Rockingham Rd. Davenport, IA PBI/Gordon Corp. 1217 West 12th Street P.0. Box 4090 Kansas City, MO 64101 Union Carbide Ag. Products Ambler, PA 19002 55101 Pickseed West Inc. P.0. Box 888 Tangent, OR 97389 * In the rush to prepare this information for the field day report, some companies may have inadvertently been missed. If your company has provided financial or material support for the research program, and is not mentioned above, please contact me so that it can be added in future reports. 131