1988 Iowa Turfgrass Research Report FG-454 | July 1988 Introduction The following research report is the eighth yearly publication of the results of turfgrass research projects performed at Iowa State University. The first was published for the 1981 field day, which was held June 18, of that year. The others were published in conjunction with the 1982, 1983, 1984, 1985, 1986 and 1987 field days. The first cultivar and management studies at the field research area were seeded in August 1979, and many of these investigations are now in their ninth season. The research was expanded between 1979 and 1983 to 4.2 acres of irrigated and approximately 3.0 acres of nonirrigated research area. Funding was obtained in 1983 to add 2.7 acres of irrigated re­ search plots to the existing site. This construction was completed in the spring of 1985. Several new studies were initiated on this area in the 1985, 1986, and 1987 seasons and a map showing the location of these studies can be found in this report. The expansion that has taken place since 1979 would not have been possible without the cooperation of the Iowa Agriculture Experiment Station, the Iowa Turfgrass Institute, the Iowa Golf Course Superintendent’s Association, the Iowa Professional Lawn Care Associa­ tion, and the Iowa Turfgrass Producers and Contractors (ITPAC) organization. We would also like to acknowledge Kenneth Diesburg, Richard Moore, Young Joo, Michael Burt, Zachary Reicher, Jim Walser, Pat Emge, Pat Gradoville, Mary Boyle, Paul Dayton, and all the others employed at the field research area in the past year for their efforts in building the program. In December of 1987, Ken Diesburg, who had managed the activities at the turfgrass research areas for nearly five years, graduated and left that position. Richard Moore, who had worked at the research areas in a part-time capacity for three years, took over the posi­ tion in March of 1988. The 1988 season will involve considerable renovation of older studies and the initiation of new projects. Those who attend the 1988 Field Day will notice that a number of old projects have been eliminated and that preparation of new sites is well underway. A special thanks goes to Betty Hempe for her work on typing this publication. Edited by Nick Christians, professor, turfgrass science; Michael Agnew, assistant professor, turfgrass extension; and Elaine Edwards, extension communication specialist. Table of Contents ENVIRONMENTAL D A T A ................................................................................................................................... 1 - 2 TURFGRASS RESEARCH AREA M A P S ......................................................................................................... 3 - 5 SPECIES AND CULTIVAR TRIALS Results of High- and Low-Maintenance Kentucky Bluegrass Regional Cultivar Trials - 1 9 8 7 ...................................................................................................... 6 Regional Perennial Ryegrass Cultivar Evaluation .............................................................................. 14 Perennial Ryegrass Cultivar Evaluations............................................................................................. 16 Fine Fescue Cultivar T ria l...................................................................................................................... 17 Fine Fescue Management S tu d y ......................................................................................................... 19 Tall Fescue Management Study .......................................................................................................... 21 FERTILIZER INVESTIGATIONS Evaluation of Different Granular Nitrogen Sources for Maintenance Fertilization of Kentucky bluegrass........................................................................ 23 Summer Slow-Release Nitrogen Sources Comparison S tu d y......................................................... 25 Evaluation of Liquid Fertilizer Programs on Three Kentucky Bluegrass Cultivars ....................................................................................................... 27 Fertilizer Burn S tu d y ............................................................................................................................... 37 HERBICIDE STUDIES Preemergence Crabgrass Control Study -1987 ................................................................................ 39 Postemergence Annual Grass Control Study -1987 ......................................................................... 42 Broadleaf Weed Control Study -1987 ................................................................................................. 44 Preemergence Herbicide Timing Control Studies -1 9 8 7 .................................................................. 54 Herbicide Effects on Rooting of Kentucky Bluegrass........................................................................ 56 Herbicide Effects on the Establishment of Kentucky Bluegrass Sod............................................... 60 Solvent Effects on Plant Response to Preemergence Herbicides on Tissue Culture M edia....................................................................................................................... 63 Poa annuaControl S tu d y --1986-87 ..................................................................................... 65 Preemergence Herbicide and Core Cultivation Study....................................................................... 67 STRESS STUDIES Cultivation Intensity Study........................ 69 Summer Stress Survival Study of Kentucky Bluegrass Cultivars..................................................... 72 INSECT CONTROL Comparative Effectiveness of Insecticides Against Annual White Grubs -1 9 8 7 ............................................................................................................ 74 TURFGRASS DISEASE RESEARCH Evaluation of Fungicides for Control of Brown Patch on Bentgrass -1 9 8 7 ......................................................................................................................... 77 Evaluation of Fungicides for Control of Foliar Diseases on Park Bluegrass -1 9 8 7 ....................................................................................................................... 79 Supplementary Evaluation of Fungicides for Eradication of Dollar Spot on Bentgrass -1987 .................................................................................................... 81 Evaluation of Fungicides for Control of Fairy Ring on Bluegrass -1987 ......................................................................................................................... 83 Evaluation of Fungicides for Control of Dollar Spot in Emerald Bentgrass -1 9 8 7 ........................................................................................................... 84 Effect of Endophyte Infection of Perennial Ryegrass on Growth Under Drought S tress.................................................................................................. 86 INTRODUCING The Iowa State University Personnel Affiliated with the Turfgrass Research Program ........................................................................... 88 COMPANIES AND ORGANIZATIONS that made donations or supplied products to the Iowa State University Turfgrass Research Program ............................................................... 89 ■n Z - > Z X - i - * K) K>Gi oi AAai ( j i a>a>Ni Ni ai ai > r r Ww □ > H W> 1 H FI o w -< r 2 - QJ Z 0 ni r AND SYMBOL TEMPERATURE 1987 DIAMOND D > H FI 1 w m io z - 30MAR OMAO»QJOMA(J>OOOKDAaiCBOK)AO)aiOK)Aa>Ol)0 19APR 09MAY 29MAY 28JUL RAINFALL 1987 1SJUN 0 8 JUL DATE 17AUG 06SEP 26SEP 1©OCT CD 00 -P* m X ■ Ö 0) 3 0) ô 3 CDC c1 2 co Eo â s (A (û > S > < CD h. U) o <0 33= Common Vantage Parade Herbicide Trials Herbicide Trials Herbicide Trials Ram I Premium Sod Blend Baron (Non-lrrigated) Parade Sod Production Study Sod Re-establishment P. Ryegrass Cultivar Evaluations Buffalograss Management Study Tall Fescue Tall Fescue Management Study Park Texoka Baron Tall Fescue Establishment Trail Sod Establishment Study Parade Preemergence Herbicide Studies Fine Fescue Cultivar Trials 1 1 1 1 1 1 1 I Bentgrass Cultivar Study Penneagle Fungicide Trials i 1 Common Kentucky Bluegrass Compaction Study Fine Fescue Management Study N & K Study Phosphorus Fertilization Demonstration Rugby Premium Sod Blend Baron Urease Inhibitor Trials National Kentucky Bluegrass Trial CD Turfgrass Research Park Fertilizer Trail Sharps Perennial Ryegrass Cultivar Evaluations Tall Fescue Kentucky Bluegrass Seed Mixtures Baron I Park Creeping Bentgrass Penncross Sod Rooting Studies Emerald Fungicide Trails Park Kentucky Bluegrass Emerald Penneagle Penncross .. Building N I______________ I Regional Kentucky Bluegrass Study “Low Maintenance” Maintenance Building Road East Research Area 5 Results of High- and Low-Maintenance Kentucky Bluegrass Regional Cultivar Trials -1987 N. E. Christians The United States Department of Agriculture (USDA) has initiated several regional Kentucky bluegrass cultivar trials presently being conducted at most of the northern agricul­ tural experiment stations. The test consists of either 80 or 84 cultivars, the number depend­ ing on the year the trials were initiated, with each cultivar replicated three times. Three separate trials are underway at Iowa State University. One is a highmaintenance study established in 1981 that receives 4 lb N/1000 ft2/yr and is irrigated as needed' another is a low-maintenance study established in 1980 that receives 1 lb N/1000 fr/y r in September and is not irrigated. The third trial was established in 1985 and receives 4 lb N/1000 fr/y r but is not irrigated. The objective of the high-maintenance study is to inves­ tigate the performance of the 84 cultivars under a cultural regime similar to that used on ir­ rigated home lawns in Iowa. The objective of the low-maintenance study is to observe the performance of the 84 cultivars under conditions similar to those that would be used in a park, school yard, or other low-maintenance areas. The objective of the third study is to observe the response of 80 cultivars under conditions similar to those found in a nonirrigated lawn that receives a standard lawn care program. The values listed under each month in tables 1, 2 and 3 are the averages of ratings made on three replicated plots for the three studies. Yearly means of all the months data were taken are listed in the last column. The first cultivar received the highest average rating for the entire 1987 season. The cultivars are then listed in descending order of average quality. The least significant difference (LSD) value listed at the bottom of each column is a statistical value that can be used to further evaluate the data. For cultivars to be con­ sidered different from one another, their mean quality ratings must exceed the LSD value. For example, the yearly means for the high-maintenance cultivars must exceed 0.7, the LSD for that column (Table 1). Midnight with a mean reading of 8.1 performed better than Cheri with a reading of 7.3. However, the performance of Midnight was statistically the same as Glade that had a yearly mean of 7.5. Midnight, CEB VB 3985, PSU-173, Ram-1, and Glade were the best of the cultivars in the high-maintenance trial (Table 1). Midnight, Glade, and Ram I have consistently performed well over the past few years and can be considered to be among the best cultivars for Iowa conditions on high-maintenance sites, although it should be noted that Midnight greens-up late in the spring and has been observed to be quite susceptible to powdery mildew in the shade. 6 This is the first year that data are reported for the nonirrigated high-maintenance trial and much of the differences in ratings may be due to establishment differences. This study will continue for several years. True differences due to variations in adaptation to this manage­ ment regime will become more apparent over the next few years. K3-162-1, Kenblue, S. D. Common, S-21, and Argyle were the top rated cultivars in the lowmaintenance trial (Table 3). Many cultivars that ranked in the upper 25 positions in 1986 have been ranked much lower in dryer years. In choosing cultivars for low maintenance conditions, data from several years should be considered. In most years, cultivars that performed well under high-maintenance conditions did not do as well under low-maintenance conditions. Conversely, many of the poorer cultivars in high-maintenance areas were the best in the low-maintenance study. This trend can be ob­ served by studying tables 1 and 3. 7 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. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33. 34. 35. 36. 37. 38. 39. 40. 41. 42. 43. 44. 45. 46. 47. The 1987 quality ratings for the high-maintenance regional Kentucky bluegrass test established in the fall 1981. Cultivar May June July Aug Sept Oct Mean Midnight CEB VB 3965 PSU - 173 Ram - 1 Glade Enmundi WW Ag 478 AZO AZO - 6A Cheri PSU - 150 Holiday Merit AZO - 6 Bristol N535 BA - 61 - 91 Adelphi 243 PSU - 190 Aspen Vanessa I - 13 Mona Viola Enoble Merion Eclipse Kimono WW Ag 480 Mosa Mer pp 300 Nugget Banff MLM - 18011 WW Ag 480 Cello Majesty H - 7 Mer pp 43 Admiral Birka Baron Plush Parade Columbia Sydsport .7 8 .0 7 .3 7 .7 6 .7 7 .7 8 .0 7,.7 7..3 7 .3 6 .7 7,.3 7,.7 6,.7 7..0 7,.3 7,.3 6..3 7..7 7..3 7,.3 7..7 6..7 7..3 7..0 7..0 7..0 6..7 7..0 7..0 7..3 7..3 7..0 7..3 7,.7 6,.7 7,.0 6,.7 7..0 6,.7 6,.3 7..0 6..7 7..0 6..3 6..7 6..3 8,.7 8,.3 8,.0 7,.7 7,.7 8 .0 6 .3 7 .3 7 .3 7 .7 7 .7 7..0 7 .3 7,.0 7 .3 7,.0 7,.3 7..3 6 .7 6 .0 7,.0 6 .7 7,.3 6,.7 7..0 7..7 7.,0 7..3 6..0 8..0 8,.0 7..7 6,.3 6,.3 7,.3 6,.0 7,.3 6,.3 6,.7 6,.7 6..0 6..7 7..3 7..0 7,,0 6..0 7..7 8,.7 8..0 7.,7 7..3 7..7 7..3 7.,0 8..3 7..3 7,.0 8 .3 7,.0 8 .0 7,.3 7,.3 6,.7 7,.3 6,.3 7,.3 7,.7 7..3 7,.0 7,.7 6..7 7..3 7..0 7..3 7..0 7..0 7,,0 6.,7 7..0 7..3 7..0 5..7 6..3 6..7 7.,3 6..7 6..7 7..0 6..7 6..7 6..7 6..3 6..3 6..3 8 .7 7 .7 7 .3 7,.3 8 .3 7..7 7,,3 8..3 7..0 7..3 8..0 7,.7 8 .0 8 .0 7..7 6 .7 7 .3 7 .3 7 .3 7 .0 6 .7 6 .7 8 .0 6 .7 7,.0 7..7 7..0 7..7 7..3 6..7 6,.0 7..3 7,.0 6 .7 6..7 6.,7 6.,7 7.,3 7..0 7..0 7..3 7..3 7,.3 6 .7 6,.3 7..7 7..0 8.,3 8..3 8..0 7..7 7,.7 8 .0 8 .3 6 .7 7..7 7.,7 7..0 7.,7 7..0 7,.3 7..3 8 .0 7 .7 7 .7 7 . .0 7 .3 7 .3 7 , .7 6 .3 8 .0 7,.7 7..0 8..0 7,,0 7,.3 7,.0 7..3 7,.0 6..3 7..7 7..3 7..7 7..7 -, 6..3 7..0 7,.7 7..7 7..0 6,.7 6..7 7..3 7..3 7..0 6..3 7..7 7.,7 7..7 7..0 6..0 7,,3 6..3 7,.7 7,.0 6..0 7.,3 6..0 7..3 7..0 7,.7 6 .0 7,.3 6 .3 7,.0 6 .7 7,.0 6,.3 7,.0 6,.3 6..3 6..3 6..7 7..3 6..3 6..7 5..7 7..3 6..7 7..0 8..0 6..3 7..3 7..0 6..7 7..0 6.,3 6..3 7. 0 7.,3 7. 0 6. 3 8..1 8,.0 7,.7 7,.6 7,.5 7,.4 7,.4 7..4 7..4 7,.3 7,.3 7..3 7,.3 7..3 7,.3 7,.2 7..2 7,.1 7,.1 7,.1 7..1 7,.1 7..1 7,.1 7,.1 7..1 7..1 7..1 7,.0 7..0 7..0 7..0 6,.9 6,.9 6..9 6,.9 6..9 6,.9 6..9 6..9 6..9 6.,8 6..8 6..8 6..8 6..8 6..8 7 8 Table 1. 48. 49. 50. 51. 52. 53. 54. 55. 56. 57. 58. 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. (continued) Cultivar May June July Aug Sept Oct Mean 225 Barblue Welcome Apart SH - 2 Escort K1 - 152 FyIking 239 Trenton Rugby Dormie Touchdown Harmony Bonnieblue Charlotte NJ 735 Bayside K3 178 Bono Monopoly Wabash American Shasta A - 34 S - 21 Geronimo Kenblue Argyle S . D . Common K3 - 179 Vantage P 141 (Mystic) Piedmont K3 - 162 SV - 01617 Lovegreen 6..3 7..3 6..0 6..7 6.,0 6..7 6..3 7..3 7..0 6..3 6..7 6..7 6..3 7.,0 7..0 6.,3 6..0 6..0 6..7 6.,7 6..0 6..0 6..3 6..0 6.,3 5..7 6.,3 5..3 5..7 5..3 6..0 5..7 5,.7 5,.7 5 .3 6 .3 5 .7 6..3 6..3 6..0 6..0 7..0 5,,0 6..7 6..3 6..0 6,,7 6..0 6,.0 6..0 6..7 6..0 5,.3 5..3 6..0 5..7 6.,0 6..0 6..3 6..3 6..0 6..0 5..7 6..0 5..3 6,.0 5 .7 5,.7 6 .3 5 .3 5 .7 5 .0 4 .3 4 .7 6.7 7.0 7.0 7.3 6.3 6.3 6.7 6.0 6.3 6.3 6.3 6.0 6.7 5.3 6.3 6.0 7.0 6.7 5.7 6.7 6.3 6.7 6.7 6.0 6.0 6.7 6.3 6.3 6.3 7.0 6.3 6.7 6.7 6.3 5.7 5.0 5.7 7.7 5.7 7.3 6.7 7.0 7.0 6.7 6.0 7.0 6.3 7.0 6.7 7.3 6.3 7.0 7.0 7.0 6.7 6.7 7.3 6.3 6.7 6.3 6.7 6.3 7.0 6.7 7.7 6.7 7.3 6.7 6.3 7.0 6.3 6.0 5.3 6.0 7..3 7,,3 7..3 7..3 6..7 7..7 7..3 6..7 6..3 7..0 6..7 7..7 7..3 7.,7 6..7 8..0 7..0 7..0 7..3 6,,7 6..7 6..7 7..0 7..0 7..0 6..7 6..3 6..3 6,.3 6,.7 7,.0 6 .7 7 .3 5 .7 7,.3 7 .0 6 .3 6.7 7.3 6.7 6.3 7.0 7.3 6.7 7.0 7.0 7.0 7.0 6.3 6.0 6.7 6.3 7.0 7.0 7.3 7.3 5.7 7.0 6.3 6.0 7.0 6.7 6.0 6.3 7.0 7.0 6.0 6.3 5.7 5.3 5.7 5.3 6.3 5.0 6..8 6..8 6..7 6..7 6..7 6..7 6..7 6..6 6..6 6..6 6..6 6..6 6..6 6..6 6..6 6..6 6..6 6..6 6,.6 6,.5 6..4 6..4 6,.4 6..4 6,.4 6,.3 6,.3 6..3 6,.3 6..3 6 .3 6..2 6 .2 5,.9 5,.8 5 .7 5,.6 LSD 1 .1 1 .4 1.4 1.3 1 .2 1.4 0,.7 0.05 , Quality based on a scale of 9 to 1; 9 = best quality, 6 = acceptable quality, and 1 = poorest quality. 9 Table 2. 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. 47. The 1987 quality ratings for the nonirrigated, high-maintenance regional Kentucky bluegrass trial established in the fall 1985. Cultivar May June July Aug Sept Oct Mean Monopoly HV 97 F-1872 Mystic Trenton Blacksburg Parade Wabash Julia K3-178 Park A-34 Ba 72-492 Ikone WW Ag 495 NE 80-14 Tendos Georgetown Conni BA 72-500 NE 80-88 Huntsville Kl-152 PST-CB1 Classic Rugby P-104 239 Aquila South DAkota WW Ag 496 NE 80-50 NE 80-30 WW Ag 491 America Ba 69-82 Loft's 1757 Compact Joy Annika Kenblue Bristol BAR VB 534 Cynthia Ba 73-540 Eclipse Haga 7.0 5.7 6.7 6.7 7.0 6.7 6.3 6.0 6.7 7.0 5.3 6.0 6.7 6.0 5.7 6.7 6.3 6.3 5.3 6.0 6.3 4.3 5.7 6.0 6.3 6.0 5.0 6.0 5.0 5.3 6.3 5.0 5.3 6.0 5.0 5.3 5.7 4.7 5.3 6.0 4.3 6.3 5.0 5.3 5.3 5.7 5.3 5.0 5.3 6.3 6.3 5.3 4.3 5.7 4.3 5.3 5.7 5.3 5.0 4.7 5.0 4.3 5.7 5.0 5.0 5.0 5.3 5.7 6.3 5.0 6.0 5.3 4.7 4.3 4.7 5.0 5.0 5.3 4.7 4.7 5.0 5.0 4.3 4.7 3.0 5.0 3.3 5.0 5.0 5.0 4.0 4.7 4.3 4.7 7.3 7.3 6.3 7.0 5.3 6.7 5.3 5.7 6.0 5.7 7.0 6.0 6.3 6.7 6.7 6.0 6.0 5.7 6.0 5.0 6.3 5.7 5.7 6.0 5.7 5.3 5.7 5.3 5.7 7.0 5.7 5.3 6.3 5.3 5.0 5.3 5.0 5.7 5.7 5.0 6.3 5.3 5.3 5.7 5.0 5.3 5.0 6.0 6.7 5.3 7.0 6.0 6.7 5.7 6.3 5.3 5.3 5.3 5.3 5.7 5.0 6.0 5.7 5.7 5.3 5.7 5.3 4.3 5.0 5.3 5.0 5.3 5.7 5.3 4.7 5.7 5.0 4.7 5.3 5.0 5.3 5.3 5.0 5.0 5.0 4.7 5.3 5.3 4.7 5.3 6.0 4.7 5.0 5.0 6.7 7.0 6.7 5.0 7.0 6.0 6.7 7.3 6.3 6.7 6.7 6.3 6.7 6.7 6.7 7.0 6.3 6.0 6.0 7.0 6.0 7.0 6.7 5.7 5.3 6.7 6.3 6.3 6.0 6.7 6.0 6.7 6.0 5.7 6.7 6.7 6.3 7.0 5.3 6.3 5.3 6.0 5.3 5.7 6.0 5.3 5.3 6.3 6.3 6.7 5.0 6.3 6.7 6.7 6.7 6.7 6.3 6.3 6.7 5.3 6.3 6.0 4.7 5.7 6.7 6.7 6.3 6.3 6.3 6.7 6.0 6.3 6.0 7.0 6.7 6.0 4.3 5.3 6.3 6.3 5.7 5.7 5.7 6.0 6.3 5.7 5.7 5.3 4.7 5.7 5.3 6.0 6.0 6.0 6.4 6.4 6.3 6.2 6.2 6.2 6.1 6.1 6.1 6.1 6.0 5.9 5.9 5.9 5.9 5.9 5.8 5.8 5.8 5.8 5.8 5.8 5.8 5.8 5.7 5.7 5.6 5.6 5.6 5.6 5.6 5.6 5.6 5.5 5.4 5.4 5.4 5.3 5.3 5.3 5.3 5.3 5.3 5.3 5.3 5.3 5.2 10 Table 2. 48. 49. 50. 51. 52. 53. 54. 55. 56. 57. 58. 59. 60. 61. 62. 63. 64. 65. 66. 67. 68. 69. 70. 71. 72. 73. 74. 75. 76. 77. 78. 79. 80. (continued) Cultivar May June July Aug Sept Oct Mean Somerset Ba 70-139 Amazon Sydsport Victa Ba 73-626 Cheri Midnight NE 80-110 Barzan Able I Ba 72-441 Asset Liberty Harmony Welcome WW Ag 468 NE 80-55 Gnome BAR VB 577 Ram-1 Challenger NE 80-47 Ba 70-242 Dawn Baron Nassau NE 80-48 Aspen Merit Glade Merion Destiny 5.0 5.3 6.0 5.3 5.0 4.7 5.7 6.0 5.3 4.3 5.3 4.7 5.0 5.0 4.7 5.0 5.7 4.7 5.0 4.3 4.7 4.7 4.3 4.0 4.3 4.3 4.3 4.7 4.3 3.7 3.7 4.3 3.3 4.0 3.7 4.7 4.3 3.7 4.3 4.3 4.3 4.0 4.7 3.3 3.3 4.3 4.3 4.0 3.7 4.3 3.7 4.7 4.7 3.7 4.7 3.7 3.3 4.7 4.3 3.7 3.3 4.0 4.3 2.7 3.0 3.3 5.0 5.3 5.3 5.0 5.7 5.0 4.7 4.7 5.0 4.7 5.7 4.7 5.0 5.0 5.3 4.3 5.3 4.7 4.7 5.0 4.3 4.3 4.7 4.7 4.0 4.7 4.0 4.0 4.0 4.0 4.0 3.7 3.3 4.7 4.7 4.7 4.3 5.7 5.3 5.0 4.7 5.0 4.3 5.0 5.3 4.0 4.7 4.7 4.3 4.7 4.3 4.3 4.3 4.3 4.0 4.3 4.7 4.3 4.7 3.7 4.0 4.3 3.7 4.3 4.3 3.0 6.3 6.3 5.3 5.3 6.0 5.7 5.3 5.7 5.3 5.3 5.3 5.7 6.3 5.3 4.7 6.7 5.0 6.7 5.0 5.7 6.0 5.3 6.0 5.3 5.0 4.7 5.3 5.0 4.3 5.0 5.3 4.0 4.3 6.3 6.0 5.3 6.0 4.7 5.7 5.3 5.0 5.3 6.3 5.0 6.0 5.0 5.3 6.0 5.3 4.7 5.3 5.0 5.0 5.0 5.0 5.0 5.3 5.3 4.3 5.3 5.7 5.0 4.7 4.3 4.0 4.3 5.2 5.2 5.2 5.1 5.1 5.1 5.1 5.1 5.0 4.9 4.9 4.9 4.9 4.9 4.9 4.9 4.9 4.9 4.8 4.8 4.7 4.7 4.7 4.6 4.6 4.5 4.4 4.4 4.3 4.2 4.1 3.9 3.6 LSD 1.5 1.4 1.5 .14 1.7 1.4 1. 0 0.05 Quality based on a scale of 9 to 1; 9 = best quality, 6 = acceptable quality, and 1 = poorest quality. 11 Table 3. 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. 47. The 1987 quality ratings for the low-maintenance regional Kentucky bluegrass test established in the fall 1980. Cultivar May June July Aug Sept Oct Mean K3 - 162 Kenblue S . D . Common S - 21 Argyle Piedmont PSU - 173 Plush Flyking PSU - 190 PSU - 15C Parade Vanessa Mosa Vantage Mer pp 43 K3 - 179 K3 - 178 Wabash Touchdown A - 34 BA - 61 - 91 Kimono CEB VB 39 Enoble NY 735 Merion Kl - 152 Monopoly Geronimo N 53 S Eclipse Harmony Majestic SH - 2 Admiral Escort Barblue Birka SV - 01617 MLM - 18011 Shasta Apart Sydsport Victa Adelphi Cello 5.7 3.7 4.7 4.7 4.7 5.3 5.7 5.0 5.0 5.7 4.3 4.3 5.3 5.0 4.3 5.7 4.0 6.0 6.3 5.7 5.0 5.7 5.3 6.0 5.0 5.7 5.7 4.7 6.3 6.0 5.0 5.3 4.7 4.7 6.3 5.0 4.7 4.7 5.7 5.0 4.7 5.3 5.0 6.0 6.0 5.3 5.0 4.3 4.3 4.0 4.0 4.7 3.7 4.0 4.3 4.3 4.7 4.3 4.0 4.3 4.3 4.0 4.0 4.3 4.7 3.7 4.3 4.3 4.0 4.3 4.3 4.3 4.3 4.0 3.7 4.7 4.0 4.7 4.0 4.0 4.3 4.7 4.3 4.7 4.0 4.3 3.7 3.7 4.0 3.7 4.7 4.3 3.7 4.7 6.0 6.0 6.0 5.7 5.7 5.0 5.0 4.7 4.3 4.3 5.0 4.0 4.3 4.0 4.0 4.0 4.7 4.3 3.7 4.3 4.0 4.3 4.3 3.7 4.3 4.0 4.0 4.0 3.3 4.3 3.3 4.3 3.0 3.7 3.3 4.0 3.7 3.7 3.3 4.0 3.3 3.3 4.0 4.0 4.3 3.3 3.7 5.7 6.0 5.7 5.3 4.7 4.3 4.0 3.3 3.3 3.3 4.7 4.3 3.3 4.3 4.7 3.7 4.3 3.3 3.0 2.7 4.0 3.7 3.0 2.7 3.7 3.0 3.3 4.3 2.7 3.0 3.3 3.0 3.0 3.3 3.0 2.7 2.3 3.7 2.3 3.0 3.3 2.3 3.3 2.7 2.3 3.0 2.3 5.7 6.0 6.0 5.7 5.0 5.3 5.0 5.7 5.3 4.7 5.0 5.3 5.3 5.3 5.0 5.3 5.3 4.7 5.3 4.7 5.0 4.3 5.0 4.7 4.0 4.3 4.3 4.3 4.0 4.0 4.7 4.0 4.7 4.3 3.7 4.7 4.7 4.3 4.3 4.7 4.3 4.7 4.0 4.0 3.7 3.7 4.3 6.0 6.3 6.0 5.7 5.3 5.7 5.3 5.7 5.7 4.7 4.3 5.7 4.7 4.7 5.7 4.7 5.0 4.7 5.0 5.3 4.7 5.0 4.7 5.3 5.0 5.0 5.0 5.7 4.7 4.3 5.0 5.0 5.7 5.0 4.0 4.3 5.3 4.7 4.7 4.3 5.3 5.0 4.7 3.3 3.7 5.0 4.0 5.6 5.4 5.4 5.2 5.0 4.9 4.8 4.8 4.7 4.6 4.6 4.6 4.6 4.6 4.6 4.6 4.6 4.6 4.5 4.5 4.5 4.5 4.4 4.4 4.4 4.4 4.4 4.4 4.3 4.3 4.3 4.3 4.2 4.2 4.2 4.2 4.2 4.2 4.1 4.1 4.1 4.1 4.1 4.1 4.1 4.0 4.0 12 Table 3. 48. 49. 50. 51. 52. 53. 54. 55. 56. 57. 58. 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. (continued) Cultivar May June July Aug Sept Oct Mean WW Ag 478 Lovegreen Bayside RAM - 1 243 Enmundi Trenton Banff Dormie Holiday Welcome WW Ag 463 Bono American Bonnieblue AZO - 6 H - 7 Mer pp 300 Bristol 225 239 Rugby Aspen I - 13 Mona Cheri Baron Merit Charlotte AZO - 6A Columbia Nugget AZO WW Ag 480 Midnight P 141 (Mystic) Glade 4. 3 5. 0 6. 0 5.,7 5..7 5..0 5.,3 4.,7 5.,0 4..7 4..3 6..0 5..3 6..0 5..0 5..0 5..3 5,.0 5..0 5..7 4,.7 4,.7 5,.0 5,.3 5,.3 5,.7 5,.3 4 .7 5 .0 4 .0 4 .0 4 .0 4 .0 5 .7 4 .3 4 .7 4 .0 4.0 4.3 4.3 4.3 4.0 4.7 4.0 4.0 3.7 4.0 3.3 4.0 5.0 4.3 4.0 4.0 3.3 4.7 4.0 4.0 3.7 4.0 3.3 4.7 4.7 4.0 4.0 4.0 3.7 4.0 4.0 4.0 3.3 3.7 3.7 4.3 4.0 3. 7 4. 3 4. 0 3..3 3. 3 3.,7 3.,7 3..7 3..7 3.,3 3.,7 3..0 3..7 3..3 3..7 3..0 3..7 4..0 3,.0 3,.3 3 .3 3..7 2,.7 2,.0 3,.0 3,.7 3 .3 3 .0 3 .3 3 .7 3 .0 3 .3 3 .7 3 .0 3 .3 3 .0 3 .0 3. 0 2. 7 2. 7 2. 3 3. 0 2..7 2. 3 3.,0 3..0 2. 3 3.,3 2.,0 2..3 2..3 3..3 2..3 3..0 2..0 3..3 2..7 3..0 2..7 2..7 2..3 2,.0 2,.3 2..7 2 .3 2 .7 3..0 2 .7 2 .7 3 .3 2 .0 2 .3 2 .3 2 .0 4. 0 3. 7 3. 3 3. 7 3..7 3.,7 3.,7 4..0 4.,3 4.,3 4.,3 4..0 3..7 3..7 3..3 4..3 4..0 4..0 4..0 4..0 3..7 3..3 4..3 3,.7 3..7 3 .3 3,.3 4..0 4,.0 3 .7 4 .3 3 .7 3 .3 3 .3 4 .0 3 .7 3 .7 5. 0 4. 0 3. 7 4. 3 3. 7 4. 0 4. 3 4. 3 4. 0 4..7 4.,7 4.,7 3.,7 4..0 4..0 4..7 4.,0 3.,7 4..3 3..7 4..3 4..3 5..0 4..7 4..0 3..3 3,.7 4,.0 3,.3 4,.0 4,.0 3 .7 4,.0 3 .3 3 .3 3 .0 4 .0 4. 0 4. 0 4. 0 3. 9 3.,9 3.,9 3.,9 3.,9 3.,9 3..9 3..9 3.,9 3..9 3..9 3..9 3..9 3..9 3..9 3..9 3..9 3..8 3,.8 3..8 3..8 3 .8 3,.7 3,.7 3 .7 3 .7 3 .7 3 .7 3 .6 3 .6 3 .5 3 .5 3 .5 3 .4 LSD 0.05 1 .6 N.S. 1 .2 1 .6 1 .6 1 .5 0 .8 Quality based on a scale of 9 to 1 ; 9 = best quality, 6 = acceptable quality, and 1 — poorest quality. 13 Regional Perennial Ryegrass Cultivar Evaluation N. E. Christians and K. L Diesburg This is the fifth year of data from the trial established in the fall of 1982 in conjunction with several identical trials across the country coordinated by the USDA. The purpose of the trial is to identify regional adaptation of the 48 perennial ryegrass cultivars. Cultivars are evaluated each month of the growing season for turf quality and disease. The trial is maintained at a 2-inch mowing height with 3 to 4 lb N/1000 ft2 through the growing season and is irrigated when needed to prevent drought. Preemergence her­ bicide is applied once in the spring and broadleaf herbicide is applied once in September to control weeds. There are no statistical differences among the first 30 cultivars in Table 4. Notice that several of the top performers in 1987 are experimental numbered cultivars. There has been a considerable amount of breeding and selection of perennial ryegrasses conducted in the past decade and a number of new releases of well adapted cultivars can be ex­ pected in future years. 14 Table 4. Turf quality3 of perennial ryegrass cultivars in 1987 Oct Mean 7. 7 7. 3 6. 7 7. 0 5. 7 7. 3 7. 7 7. 3 7. 0 7. 7 6. 3 6. 7 7. 3 7.,0 7.,3 6. 7 6. 0 6..0 5. 3 6.,7 6.,3 5..3 6..3 5.,3 4..7 5..7 6..0 6..3 5..7 6..0 7..0 5..7 6,.7 7,.0 5,.7 6,.0 4,.3 5,.3 4 .7 6..0 5..0 4 .7 4 .3 5 .7 6 .0 5 .0 4 .7 4 .7 8.,0 8. 0 8..3 7.,0 8.,7 8.,7 8.,3 8.,3 7.,3 7.,0 7..7 9..0 7..7 8..7 8..0 7..3 7..7 8..0 8..3 7..0 8,.0 7..3 6..7 7..3 7,.7 7..0 8 .0 7 .3 7..7 8 .0 7 .3 7 .7 7 .0 6 .7 7 .3 6 .3 7 .3 7 .3 7 .0 7 .3 7 .0 7 .7 7 .7 7 .3 6 .0 6 .3 6 .7 4 .7 6. 7 7. 3 7. 0 6..7 7.,0 7.,3 6.,0 5..7 6.,3 6.,3 6.,7 6.,7 6.,0 6.,0 5..7 6.,3 6..7 6..3 6..7 5..3 6..3 6..3 5..3 6,.0 5..7 5,.3 5..3 6..0 6..0 5 .0 5 .3 5 .3 5 .3 5 .7 4 .7 5 .3 6 .0 6 .7 5 .3 5 .3 5 .3 5 .7 5 .7 5 .0 4 .0 5 .3' 3 .7 4 .0 7. 6 7. 6 7. 5 7.,4 7.,4 7.,3 7. 3 7.,3 7.,2 7..2 7..2 7..1 7..1 7.,0 7..0 7..0 6..9 6..9 6..9 6..8 6..7 6,.7 6,.7 6,.7 6,.6 6,.6 6..6 6..6 6..6 6..6 6 .5 6 .5 6 .4 6 .4 6 .3 6 .3 6 .2 6 .2 6 .1 6 .1 6 .1 6 .0 5 .9 5 .8 5 .8 5 .7 5 .3 4 .4 7 .5 7 .0 7 .7 6 .8 6 .7 2 .0 1 .8 1 .3 1 .3 1 .0 May June July l. 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. 47. 48. 6. 0 6. 3 7. 0 8. 0 7. 3 6. 7 7. 0 7. 0 6. 0 7. 3 7. 0 7..3 6.,3 5..0 5..3 6..3 5..3 6.,3 5.,7 7.,7 6..0 7..7 7..0 7..7 7..3 6..7 6..3 7..0 5..7 6..7 6,.7 6..3 5,.7 7,.0 6..0 6..0 6..3 7..0 7..0 5 .3 5 .3 5 .7 5 .7 6 .0 6 .0 5 .0 5 .0 4 .3 9. 0 8..7 8. 3 8. 7 8. 3 7..3 7. 0 7.,7 8..7 8..0 8..3 7..0 7.,7 8.,0 7.,3 8.,0 7.,7 7.,7 8.,3 7..0 7..7 7..7 8..0 7..3 8..0 8..3 7..0 6,.7 8,.0 7,.0 7..3 7,.7 7..3 6..0 8 .0 7..7 7..0 6 .0 7 .0 6 .3 7 .7 6 .7 6 .7 6 .7 6 .3 6 .7 7 .0 4 .3 8. 0 7. 7 7. 7 7. 0 7. 7 6. 3 8. 0 7. 7 8. 0 7. 0 7. 3 6..0 7. 3 7. 3 8. 3 7. 3 8.,3 7.,0 7.,0 7.,3 5.,7 5..7 6..7 6..3 6..3 6..3 6..7 6..0 6..3 6..7 5..3 6,.3 6,.3 6..3 6,.3 6,.7 6..0 5,.0 5 .3 6 .0 6 .0 5 .7 5 .7 4 .3 6 .3 6 .0 5 .0 4 .7 6 .4 7 .5 1 .4 1 .1 SWRC - 1 GT - II BT - I Palmer 282 Prelude Pennant IA 728 Diplomat Omega Gator HR - 1 Derby Yorktown II HE 168 Blazer LP 702 LP 210 Manhattan II Pennfine Ranger Fiesta WWE 19 Birdie HE 178 Manhattan 2ED Premier M 382 Delray Dasher Gigil NK 79307 Regal Cockade Cupido Acclaim Citation Crown 2 EE NK 80389 LP 792 Elka LP 736 NK 79309 Pippin Barry Linn Ratinesa Aug Sept Cultivar E x t >eriment Ìlean LSD a 0.05 Quality based on a scale of 9 to 1; 9 - best quality, 6 = acceptable qual­ ity, and 1 = poorest quality. 15 Perennial Ryegrass Cultivar Evaluations N. E. Christians The 22 perennial ryegrass cultivars in this trial were established in 1979. The study has been maintained at a 2-inch mowing height and is fertilized with 4 lb N/1000 ft2/yr. The area receives no fungicide or insecticide applications. The 1987 season is the final year that data will be collected from this area. It will be phased out in 1988. Elka, Yorktown, Fiesta, Loretta, and Belle received the highest overall quality ratings in 1987. Regal and Pennfine ranked unusually low in this trial in 1987. This was due to the development of a disease believed to be Brown Patch in these two cultivars in midsummer. Regal also ranked somewhat lower in the newer perennial ryegrass trial (Table 5), than in earlier years, however, Pennfine in that trial ranked with the better cultivars. It is not un­ usual for certain cultivars to deteriorate in quality in older trials. Table 5. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. The 1987 quality ratings for 22 perennial ryegrass cultivars established in 1979. Quality Ratines July Aug Cultivar May June Elka Yorktown Fiesta Loretta Belle Diplomat Caravelle Medaliest North Delray Derby K5 - 88 Manhattan Citation Blyes K5 - 94 Goalie NK - 100 J186 R24 D Regal NK - 200 Linn Pennfine 6.7 8.0 7.0 7.3 7.7 7.0 6.7 6.7 6.7 7.3 5.0 7.3 6.7 7.0 7.3 6.0 5.3 6.0 5.3 6.0 5.0 5.0 8.7 8.0 8.3 8.3 8.0 7.3 6.7 6.7 7.3 7.0 6.7 6.7 6.7 7.0 7.0 6.7 5.3 6.0 6.0 6.0 5.0 5.5 7.3 7.0 6.3 5.7 7.0 7.0 5.7 6.3 5.0 6.0 5.0 5.3 5.7 6.3 4.7 4.7 4.3 4.3 4.7 4.3 4.7 5.0 LSD 1.4 1.7 1.8 0.05 Sept Oct Mean 5.3 7.0 6.0 5.3 5.7 5.7 5.3 5.0 6.3 5.7 5.3 5.0 5.7 5.3 4.3 4.7 4.3 4.0 4.7 4.3 3.7 4.5 7.0 7.0 7.0 7.0 6.3 6.7 6.3 7.0 6.3 5.0 6.3 6.3 6.0 4.3 6.0 5.3 6.7 5.3 5.0 5.0 5.7 4.0 6.7 4.7 6.5 6.3 5.7 5.0 6.0 5.0 4.7 5.0 7.3 5.0 5.0 5.0 4.3 5.3 5.7 5.3 5.7 5.0 5.3 4.0 6.9 6.9 6.8 6.7 6.7 6.4 6.1 6.1 6.1 6.0 5.9 5.9 5.9 5.8 5.6 5.4 5.3 5.2 5.2 5.1 4.9 4.7 N.S. N.S. 1.8 1.2 Quality based on a scale of 9 to 1; 9 = best, 6 = acceptable, and 1 = poorest. 16 Fine Fescue Cultivar Trial N. E. Christians and K. L. Diesburg This is the fifth year for the fine fescue cultivar trial established in the fall of 1982. The purpose of the trial is to identify regional adaptation of the 32 fine fescue cultivars and blends in a full sun exposure. Cultivars are evaluated each month of the growing season for turf quality. The trial is maintained at a 2-inch mowing height with 3 to 4 lb N/1000 ft2 through the growing season and is irrigated when needed to prevent drought. Preemergence her­ bicide is applied once in the spring and broadleaf herbicide is applied once in September to control weeds. Shadow, Banner, Checker, Scaldis, and Atlanta were the best cultivars under these conditions in 1987 (Table 6). Many of the cultivars have allowed the encroachment of Ken­ tucky bluegrass since 1982. Tournament, Pennlawn, NK79190, NK79191, NK80345, NK80347, NK80348, and Duar had 20 to 80 percent Kentucky bluegrass in two or three of their replications. This may be due to a lack of competitiveness with Kentucky bluegrass. There also may have been some contamination of the experimental cultivars with bluegrass seed at the time of establishment. This trial will be eliminated in 1988. A new shade study that includes many of the fine fescues was established in the fall of 1987. 17 Table 6. 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. a Turf quality ratings of fine fescue cultivars and blends Turf Oualitva Aug Sept Cultivar May June July Shadow Banner/Checker Banner Checker Scaldis/Atlanta Atlanta Barfalla Dawson Agram Waldina Jamestown Aurora FOF - WC Ruby Koket Wintergreen NK 80346 Dawson/Pennlawn Ensylva Pennlawn Scaldis Highlight NK 79189 Fortress Biljart Duar NK 79190 Tournament NK 80345 NK 79191 NK 80347 NK 80348 8.7 6.7 7.7 6.0 7.7 7.3 5.7 5.0 6.7 5.3 6.0 4.7 5.0 4.7 5.0 5.0 6.3 3.7 4.3 4.3 4.0 3.7 4.7 3.0 4.7 4.3 2.3 3.0 2.7 3.0 3.7 2.7 9.0 8.7 8.3 8.7 8.7 8.0 8.0 8.3 8.3 5.7 6.3 5.7 5.3 6.0 6.0 6.7 5.3 6.0 5.7 5.0 5.0 3.0 5.7 5.3 3.3 4.3 3.3 3.0 3.3 3.0 7.3 7.0 7.0 7.7 7.0 6.7 6.7 7.0 5.0 5.3 5.3 5.0 5.3 6.3 5.0 4.0 6.3 4.7 4.7 4.7 5.0 2.3 4.7 2.3 3.0 4.0 2.3 2.7 3.0 6.0 6.3 5.3 4.7 4.3 4.3 4.0 4.0 4.3 5.0 4.0 5.0 4.7 4.0 3.7 2.7 1.7 3.3 3.0 3.7 3.7 3.7 3.0 2.3 3.0 2.3 2.0 2.3 2.3 5.0 6.3 4.7 5.0 4.0 4.3 4.3 4.3 5.0 4.7 4.3 5.0 4.7 5.3 4.7 4.0 3.0 3.7 3.3 3.7 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 LSD = 0.05 3.8 4.5 3.7 2.9 Oct Mean 6.3 6.0 6.7 5.3 5.7 5.7 5.3 5.7 4.3 4.7 4.3 4.7 4.7 3.3 4.3 4.0 2.3 4.0 3.7 3.0 4.7 4.3 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 7.1 6.8 6.6 6.2 6.2 6.1 5.7 5.7 5.6 5.1 5.1 5.0 4.9 4.9 4.8 4.4 4.2 4.2 4.1 4.1 3.9 3.3 3.3 3.2 2.9 2.9 2.5 2.2 2.2 1.7 1.4 1.3 3.7 3.2 2.9 1.0 2.7 1.0 1.0 3.0 1.0 3.0 2.7 1.7 2.3 2.7 1.0 1.0 1.0 Quality based on a scale of 9 to 1: 9 = best quality, 6 = acceptable quality, and 1 - poorest quality. 18 Fine Fescue Management Study N. E. Christians The fine fescue management study includes the following cultivars: 1. 2. 3. 4. 5. Pennlawn Red Fescue Scaldis Hard Fescue Ruby Red Fescue Atlanta Chewings Fescue K5-29 Red Fescue 6. 7. 8. 9. 10. Dawson Red Fescue Reliant Hard Fescue Ensylva Red Fescue Highlight Chewings Fescue Jamestown Chewings Fescue Each cultivar is maintained at two mowing heights: 1 and 2 inches. Each plot is divided into two fertilizer treatments: 1 and 3 lb N/1000 ft2, applied as IBDU. Each plot is irrigated as needed. The study was established on September 8, 1979. The quality ratings in table 7 are the means of monthly ratings taken on repli-cated plots from May to October. As has been the case for several years, Reliant and Scaldis Hard Fescue had the best overall quality for the year (Table 7). Jamestown chewings fescue also performed very well in 1987. At the 2-inch mowing height, only Reliant and Scaldis maintained a satisfactory quality rating of 6 or better at the 1 lb N/1000 ft2/yr fertility rate. At the 3 lb N/1000 ft2/yr rate, most of the grasses tested were acceptable. At the 1-inch mowing height, only Scaldis maintained a satisfactory quality at the 1 lb N/1000 ft2/yr rate. Reliant, Scaldis, and Jamestown were the best cultivars at the 3 lb N/1000 ft2/yr rate. This study has been in progress for eight seasons. The fact that any of these grasses have maintained an acceptable cover at a 1-inch mowing height for that length of time is surprising. The cultivars listed as acceptable have consistently performed well during the study. There is a large difference between poorly rated cultivars and acceptable cultivars. The choice of fine fescue cultivars for this region should be made carefully, as many are not well adapted to Iowa conditions. 19 Table 7. The effects of mowing height and nitrogen fertilizer on quality of 10 fine fescues. Mowine Height 2 inch 1 inch N Rate N Rate 1 lba 3 lb 1 lb 3 lb Overall Mean 1. Pennlawn Red Fescue 5.0b ’c 5.6 5.7 2. Scaldis Hard Fescue 6.2 6.7 6.8 3. Ruby Red Fescue 4.1 4.8 5.1 6.2 5.0 4. Atlanta Chewings Fescue 5.6 5.8 5.8 6.2 5.8 5. K5-29 Red Fescue 4.7 4.9 5.1 5.7 5.1 6. Dawson Red Fescue 4.2 4.5 3.0 5.7 4.8 7. Reliant Hard Fescue 6.1 6.7 6.7 7.3 6.7 8. Ensylva Red Fescue 4.2 4.7 5.3 6.7 5.1 9. Highlight Chewings Fescue 3.6 3.6 4.0 4.1 3.8 10. Jamestown Chewings Fescue 5.8 6.6 5.8 6.8 6.3 6.3 5.7 CM 6.7 a 2 N rates are in lb N/1000 ft /yr. k Values are the means of monthly observations from May to October. c Quality based on a scale of 9 to 1; 9 — best quality, 6 = acceptable qual­ ity; and 1 = poorest quality. 20 The N source is IBDU. Tall Fescue Management Study N. E. Christians and K. L. Diesburg This is a report of the fourth year of data from the experiment. It is designed to compare the response of Falcon, Houndog, Kentucky 31, Mustang, and Rebel tall fescue at 0, 2, and 4 lb N/1000 ft42/yr and cutting heights of 2 and 3 inches. One pound of N was applied once during each month of May and September fo r(tbe 2-lb treatment and during April, May, August, and September for the 4-lb treatment. In the strip-split plot arrangement, all six combinations of the two management factors are placed in a 2 ft by 3 ft block within each cultivar with the five cultivars replicated three times.j The 2-inch cut resulted in higher quality turf for all cultivars (Table 8). Turf quality increased with each increment of nitrogen for all of the cultivars at both mowing heights. Each cul­ tivar performed best at a 2-inch mowing height and 4 lb N/1000 ft2/yr. Mustang was the best cultivar under higher maintenance conditions in 1987. In general, each of the turf-type cultivars performed better than Kentucky 31. 21 Table 8. Cultivar Turf quality of tall fescue cultivars at two clipping heights and three fertility levels. Clip Hgt inch lb N/ 100^ ft _______________ _____ Ratings5 Aug May June July Sept Oct Mean Mustang 2 2 2 3 3 3 0 2 4 0 2 4 5.0 5.0 7.0 4.3 4.0 6.0 4.0 5.0 7.3 3.7 5.0 7.0 5.3 6.7 8.0 4.3 6.3 7.7 4.3 5.7 7.0 4.0 5.3 7.3 4.7 4.7 7.7 4.7 4.7 7.3 4.0 5.3 7.0 3.0 4.3 6.3 4.6 5.4 7.3 3.0 4.9 6.9 Houndog 2 2 2 3 3 3 0 2 4 0 2 4 5.7 5.3 7.0 4.3 4.3 5.7 4.0 5.0 8.0 4.0 5.0 7.0 5.0 6.7 7.7 4.0 6.0 7.3 4.3 6.0 6.7 4.0 5.0 6.3 5.7 6.7 4.7 5.7 6.3 4.3 4.0 5.0 6.7 3.0 4.0 6.3 4.8 5.8 6.8 4.2 5.1 6.2 Rebel 2 2 -2 3 3 3 0 2 4 0 2 4 5.0 5.3 7.0 4.0 4.3 6.0 4.0 5.0 7.7 3.3 5.0 7.0 6.0 6.3 6.7 5.3 5.7 6.0 4.0 5.0 5.3 3.6 4.7 6.3 6.0 5.0 4.0 6.3 5.0 3.7 4.0 5.0 6.3 3.3 5.0 6.0 4.8 5.3 6.2 4.3 4.9 5.8 Falcon 2 2 2 3 3 3 0 2 4 0 2 4 5.0 5.0 7.0 4.0 4.0 6.0 4.0 5.0 8.0 3.7 5.0 7.0 4.7 6.3 8.0 4.0 5.7 7.0 4.7 6.0 6.3 4.0 5.0 6.3 5.0 6.0 4.3 5.0 5.7 4.0 4.0 5.0 7.0 3.0 4.0 6.0 4.6 5.6 6.8 3.9 4.9 6.1 Kentucky 31 2 2 2 3 3 3 0 2 4 0 2 4 4.3 4.7 6.0 4.0 4.0 5.0 3.7 4.7 6.0 3.0 4.3 6.0 3.3 5.3 7.0 3.0 5.0 6.0 3.7 4.7 •6.7 3.7 5.0 6.3 4.3 7.0 4.7 4.0 7.0 4.3 2.7 4.3 6.0 2.0 3.7 5.0 3.7 5.1 6.1 3.3 4.8 5.4 0.3 0.4 0.2 0.5 0.3 0.6 0.9 1.1 0.8 0.8 0.4 0.5 0.3 0.3 LSD cultivar averages LSD managements a Quality based on a scale of 9 to 1; 9 « best quality, 6 = acceptable quality and 1 - poorest quality. 22 Evaluation of Different Granular Nitrogen Sources for Maintenance Fertilization of Kentucky Bluegrass M. L. Agnew, N. E. Christians, and R. W. Moore In this study, seven granular nitrogen (N) sources are being evaluated for maintenance fertilization. The turf is Glade Kentucky bluegrass established in September, 1984. It is maintained at a cutting height of 2 inches. The study is replicated three times in a com­ plete block design. Plot size is 3.5 ft X 7 ft. The treatments include six slow-release N sources applied at 4 lb N/1000 ft2/year split into two equal applications. The six slow-release N sources include: IBDU and Plastic Coated Urea (PCU) from Estech Corporation, Sulfur Coated Urea from the Anderson Company (SCU/CIL), Sulfur Coated Urea from the Lesco Company (SCU/TVA), Methylene Urea from O.M. Scotts, and Ureaformaldehyde (UF) as Blue Chip from the NOR-AM Company In ad­ dition, one urea treatment was applied at 4 lb N/1000 ft2/year split into four equal applica­ tions. Treatments were initiated in the spring of 1985. The dates of fertilizer application are May 1 and August 15. The additional urea treatments were applied on June 1 and Septem­ ber 15. The results of the 1987 data indicate that urea, SCU/CIL, SCU/TVA, and PCU/Estech provided the overall best quality (Table 3}^while IBDU and Blue Chip had the poorest over­ all quality. SCU/TVA, SCU/CIL, urea, and methylene urea produced more clippings follow­ ing the spring application of fertilizers (Table 10)/Whereas, there was no difference in the density of the turf and thatch depth among the treatments. 23 Table 9. Effects of granular N sources on visual quality. Nitrogen Source Visual Oualitva 5/27 6/09 6/25 4/20 5/14 Urea IBDU SCU/CIL SCU/TVA Methylene urea UF/Blue chip PCU/Estech 6.5 4.7 6.3 6.0 6.3 5.3 7.0 7.5 4.3 7.3 8.0 6.7 5.0 5.3 6.5 5.3 7.7 8.0 7.3 5.0 5.7 8.0 6.0 7.0 6.7 5.7 5.0 6.3 LSD = (0.05) 0.8 1.1 0.8 0.7 Table 9. 7/21 8.0 6.0 7.3 6.7 5.7 6.0 8.0 6.5 5.3 6.7 6.7 5.3 6.3 8.0 8.5 7.3 7.3 7.7 7.7 7.4 8.7 0.8 1.5 NS Visual Quality 9/04 9/16 10/14 10/27 Mean (continued) Nitrogen Source Urea IBDU SCU/CIL SCU/TVA Methylene urea UF/Blue chip PCU/Estech LSD - (0.05) a 7/07 8/04 8/20 7.0 6.0 5.7 6.0 6.3 5.7 8.0 6.5 5.3 7.0 7.7 6.7 6.0 5.6 6.0 5.0 8.0 7.7 6.7 5.0 6.3 6.0 5.3 8.0 7.7 7.0 5.3 7.3 8.0 4.7 6.3 6.3 5.3 5.3 7.7 8.0 5.7 6.3 6.3 6.0 5.7 7.7 7.2 5.5 7.0 7.0 6.4 5.6 7.1 NS 0.8 0.6 0.8 2.0 1.4 0.5 Visual quality is based on a scale of !? to 1; 9 = best possible quality, 6 = acceptable quality, and 1 — dead turf. Table 10. Effects of granular N sources on shoot density, clipping yields, and thatch development. Nitrogen Source Urea IBDU SCU/CIL SCU/TVA Methylene Urea UF/Blue chip PCU/Estech LSD - (0.05) Shoot Densitva 6/23 Clipping; Yields^ 5/22 6/16 Thatch Development0 5/21 72.8 50.8 60.0 59.8 63.3 57.5 57.8 73.2 57.1 71.5 78.2 77.2 63.7 67.1 55.4 50.8 51.2 54.6 50.1 46.8 49.9 19.8 19.3 21.1 20.2 18.6 19.4 18.6 NS 8.6 4.4 NS a Shoot density = number of tillers per 15 square inches, k Clippings yields = dry weight of clippings removed. c Thatch development = mm depth of the thatch layer. 25.4 mm = 1 inch. 24 Summer Slow-Release Nitrogen Sources Comparison Study M. L. Agnew, N. E. Christians, R. W. Moore The purpose of this study was to compare eight slow-release N sources for the summer application of nitrogen. The turf is Glade Kentucky bluegrass, established in September 1984. Treatments were initiated in the spring of 1985 and will continue for several years. Individual treatment cells measured 5 ft x 5 ft and were randomized in a complete block design with three replications. The turf was mowed at 2 inches and water was applied to prevent drought stress. Treatments include eight slow-release N sources applied at 2 lb N/1000 ft2/season split into two equal applications on May 20 and August 10. Each treatment received 2 lb N/1000 ft2/season of urea (46-0-0) split into two equal applications on April 10 and September 20. One additional treatment, which included combinations of Powder Blue and urea, was ap­ plied for comparison. This 0.25 lb N treatment applies 0.25 lb N (Powder Blue)/0.75 lb N (urea in April, 0.5 - 0.5 lb N as Powder Blue/urea in May, 0.5 lb N (Powder Blue)/0.5 lb N (urea) in August, and 0.75 lb N (Powder Blue)/0.75 lb N (urea) in September. The N-Sure treatment was established in 1986, while the other treatments were established in 1985. Visual quality data were collected monthly from May through October (Table 11). All treatments, except Powder Blue, had an overall acceptable quality level with SCU/CIL per­ forming better for the entire season. Shoot density and thatch determinations were made once during 1987 (Table 12). There were no differences in shoot density between treatments on June 23 (1 month after applica­ tion of slow-release product). In addition, there was only a slight difference in thatch depth between the treatments (2.5 mm = 0.1 inch). SCU/TVA and SCU/CIL were the greatest thatch producers of the fertilizer sources. 25 Table 11. Effects of slow-release nitrogen sources in summer fertilization on visual quality. Slow-release N source ________________ Visual Quality3 5/18 6/15 7/17 8/17 9/16 10/14 Mean Powder Blue Fluf Formolene N-Sure IBDU SCU/TVA SCU/CIL Azolone Powder Blue/Urea 8,.0 8,.0 8,.0 8,.0 8,.0 8,.0 8,.0 8,.0 7,.6 LSD 0.05 0 .3 . 5,.0 5,.7 6,.7 6 .0 6,.7 7,.7 8,.0 5,.0 7..0 0 .6 4..3 5..3 3..7 6..0 6..7 5..7 6..7 5..7 6..7 6..3 7..3 6..3 7..0 7..3 5..7 7..3 7..3 7..7 5..3 6..0 7..3 6..3 6..0 7..3 7..3 6..0 5..0 6..3 7..3 7..7 7..3 7..3 7..7 7..7 6..7 7..0 5,.9 6,.4 6,.6 7..0 7,.0 7,.0 7..5 6..4 6..8 .2 N. s. 1..1 N..s. 0 1 . . .5 . Visual quality is based on a scale of 9 to 1: 9 - best visual quality, 6 = acceptable quality, and 1 — no live grass. Table 12. Effects of slow -release nitrogen sources in sum m er fertilization on shoot density and thatch development. Slow-Release N Source Thatch depth^ 5/21 Shoot Densitva 6/23 Powder Blue Fluf Formolene N-Sure IBDU SCU/TVA SCU/CIL Azolone Powder Blue/Urea 61.8 57.5 57.7 65.8 65.8 66.0 63.7 62.3 57.0 22.5 20.3 20.3 22.3 21.3 23.2 23.0 22.5 22.0 LSD 0.05 N.S. 2.2 a Shoot density = number of tillers per 15 square inches. k Thatch depth = mm depth of the thatch layer. 26 25.4 mm = 1 inch. Evaluation of Liquid Fertilizer Programs on Three Kentucky Bluegrass Cultivars R. W. Moore, M. L. Agnew, and N. E. Christians This study compares 12 liquid fertilizer programs using four nitrogen sources on three Kentucky bluegrass cultivars. The treatments were started in the spring of 1985 and will continue through 1990. The turf is maintained at a cutting height of 2 inches and all clip­ pings are removed. The four fertilizers include Urea, Powder Blue, Fluf, and Formolene. They were applied using different application schedules and three different application rates. Each schedule received a total of 4 lb N/1000 ft2/growing season. The balanced program received 1 lb N/1000 ft2 in each of the months of April, May, August, and September. The heavy spring program received 1/2 lb N in April, 1-1/2 lb in May, and 1 lb N each in August and Septem­ ber. The late fall program required 1/2 lb N in April, 3/4 lb in May, 3/4 lb in August, 1 lb in September, and 1 lb in November. The three cultivars of Kentucky bluegrass are Majestic (high-maintenance grass), Vantage (medium-maintenance grass), and Park (low-maintenance grass). Each cultivar was repli­ cated three times, and each of the 12 fertilizer programs were randomized within each cul­ tivar. The data taken in 1987 include visual quality, clipping weight, shoot density, thatch depth, and root weights by depth. Treatments were rated for visual quality 2 days each month, while clippings were collected dried and weighed on or about the 20th of each month. Shoot density was measured on June 23 and thatch depth and percent organic matter in the thatch layer was determined on May 22. Finally, root samples were collected in Novem­ ber 1986 and July 1987. In comparing the cultivars (Table 13), the overall visual quality ratings were equal for Majestic, Vantage, and Park. However, Majestic had substantially better quality in midJuly. In addition, Majestic produced only half to two thirds as much clipping weight as Vantage or Park. This difference is not surprising since Majestic is a prostrate-growing cul­ tivar, and Majestic had 35 percent fewer shoots than Park and Vantage. Furthermore, thatch accumulated quickest in Majestic (Table 14). In the accumulated thatch, Vantage contained 76 percent soil, while Majestic contained 65 percent soil, thus more of the thatch in Majestic is organic matter. Table 15 contains the rooting data for cultivars during Novem­ ber 1986 and June 1987. In November, Majestic contained greater amounts of roots in the upper 3 root zones. In June, both Majestic and Vantage had more roots than Park in all root zones. 27 In comparing programs (Table 16), the late fall program had the best visual quality rating and the lowest clipping yields in the spring, while the balanced program had the best over­ all visual quality. Clipping yields and shoot densities were not effected for most of the sum­ mer. However, root weights by depth were directly affected by fertilizer programs. Late fall programs had more roots in the deeper soil depths in the fall (Table 17), and more roots in the 0 to 5 cm and 5 to 10 cm depths during the early summer (Table 18). There were no effects of programs on thatch development. In comparing the individual fertilizer sources, there were little differences in the overall quality of the turf; however, urea greened up earlier in April than Powder Blue, Formolene, or Fluf (Table 19). Visual quality of Powder Blue, Formolene, and Fluf did persist longer during the summer. Formolene and urea demonstrated better visual quality longer into the fall. Urea and Formolene produced the greatest amounts of clippings during cool weather, while Fluf and Powder Blue produced more clippings during the summer. The visual quality and clipping yield data suggest that the slow-release nitrogen of the longer chain methylene ureas become more available during mid to late summer. There were no effects of fertilizer source on thatch development or root weights. In comparing programs and materials for the season, the balanced and late fall programs demonstrated the best visual quality early. The heavy spring application did result in good summer and fall response, especially from urea and Formolene. Powder Blue suggested good response from all three programs during the summer. A listing of all the data for visual quality and clippings are presented in Table 20. \ 28 VO. VO m • VO CO VO m • VO m VO CO £ CM • • •P O r^ O MlVO VO • vo m • vo CO £ 4J P-iCM 0) CM GO VO • VO in • VO • VO CO £ VO. VO vl-. VO . VO CO £ bO CO • VO in • vo in • vo CO £ H bO U G r-1 •rM <3 1—1 »—1 cd G o rM » —1 i—i G co cd •-) G w •H > »—1VO G i-i •“5 CTv . vO o oo • VO 00 VO 00 • VO CO. VO vO. VO 00 • VO 00 • VO P P< CO • rM m CO • 00 in O • vo CO OO O CM ON • in rM in • CM i—1 m • 00 P CO • VO vo m • vo • r^- rQ bO XJ G o r—1< bl •G H P P •iM rM r—1 rM G CM U •“) • r^ co CO • VO 00 VO • rM VO • in CO ON • CM VO cd o T5 iM i—1 O on Table 13. 1987 visual quality, clipping yield, and shoot density for three Kentucky bluegrass cultivars. 4-> O i—1 O CM VO • VO cd £ ■o 0) 3 C c o O cd o £ CM • 5-1 O •H cd a) •rM U rM P AS qj > qj > G o bO qj G P J-i W iM 4J rM G o 0) bO cd p G cd > 5m cd Pm •1—) cd £ in o o Q GO Clipping weights = grams of dry weight/1.63m2. Shoot density = number of tillers per 15 square inches. G cd o ex o C M rt H* < 05 tl CD CD _k Ol e'­ en O o • o Ln ►a 05 H ?r S (_05i. CD w H* O rt o C i—* rt H* < 05 3 rt 05 oq CD 05 m 3: CD ON h—1 ■P■O' • 00 00 • to VO ON • VO 1 —1 to • h-1 i —1 ■P* O LO h-* • 00 VO h-1 f—* h-* h-* • VO • -F> a C/> 53 O • VO Ln -P' • LO O • to "O • ON ON Ln Ln to \l LO ss oo 53 O C • i —* 0 1 h-1 to LO • LO ON *4> CD VO I—4 00 00 53 O < • h-* h-* VO • Ln • VO • to 00 o PTa3> LO a rt < f [ ( ( o LO Ln LO to nJq C 05 3 to 00 N° • • OO O H* O 3 05 rt rt CD H c 3 § ON 00 rt LO C 3 CD LO • PJ I-1 O) 5-20 cm J LO • •P* to h-* O • LO ON 1-* -p* o 00 Ln to ON o O LO O h-1 oo h-* CD SJ o < 5-10 cm J Ln • LO • oo Ln o c 3 CD 30 Table 14. Thatch com parison of three Kentucky bluegrass cultivars (M ay 22). ►a 05 1-1 ?r 05 (0 to rt H* O 0-5 cm Ju Rooting weights = milligrams per 5-cm depth. r1 CO o o • o p cd CD S 4J O O rH CM ON m • VO • VO VO VO VO • vO • CM • VO VO VO CO r— l > CM . W W cd U bO a) > 4J o vO • CO • VO VO VO -p CM CM CD CM co 00 • VO VO • VO CM • VO 4-> CM 0) 0 0 CO • VO VO • ON • VO m CM • m VO • VO VO o m • r - 00 p vo < J CM . o p m CO . p o p O cd 00 CO . 00 • o CM CO • • CO rH rH rH 1— 1 1— 1 00 • rH VO ON • ON in o rH • ON r - o vO • CO ON • CM Ht o <1- CO • CM 4J cd P cr CM > VO 4J CM C O CD CM CO •s • o VO CO :z i 4J cm bO P rH <3 rH cd W 4-) ON • VO a) a o cd VO >0 •rH r H i— 4 i— 1 • oo CM > P O PO rH • • cd •H P VO 00 • CM • VO o bO 4>J>> p p •H CD P o P CO 0) p P CO • m rH • *-> VO • m VO VO 00 • CO • VO VO • CO iz ; r - .JQ T ) rH CD •rH cd 1— 1 cd r— 1 V O rH CO •rH ° VO CM • p r— l r H p •r4 p i CM f— 1 o on v f CO • • in ON • o o P ON <4H m cd cd a o cm p CM 0 0 CD cc r— i rH cd Mh CD •P cd iJ m n VO CM • CO VO a> 13 C (c1o) cd o cd O a S CM • oo VO 4-) •H CD cd 3 cr a> JQ CO H Q CO ij in T3 rQ o • o m cd o ON CM • CO VO o w P VO i— 4 • T) (D O P CO CM . • VO in cd 31 p cd > •rH 4J rH p o CD o c cd rH cd eq bO p •r4 > h VH > CM cd co CD K r— l r— 1 cd r^ CM m o . Pm CD cd 4J 1-1 o Q CO -3 Clipping weights = grams dry weight/1.63 m2. Table 16. 1987 visual quality, clipping yields, and shoot density of three liquid fertilizer program s. •rH VO CM • sc Rooting weights = milligrams per 5-cm depth. r 1 A3 ft o w P3 1— ' A3 3 o CD CD CD < o • ►n A) M M o Ln CD CO T) d H» d OP a OP d § -a . 00 m I Ln do 00 o av 00 CO CO Ln o A3 i- * o H Q> a (D h -1 H» do do ■ P* DO i- * H» o M CO O CO =* (D a 0) (D a. N (D 73 O (Q -n 0> (SO 00 Ln Ov ov CO SJ CO ÍZ5 CO vo VO DO rt H* Ln -P> (D h-» O O «-+ 5‘ (Q Ln O • h -1 -P * ov • 4> CO • o f-1 CO DO • Ln DO VO • • VO 4> £¡ CO 3 5Z¡ CO do ■ P* • DO CO • o O *d ft A3 H» I-1 I—1 av vo i-* o 1—* I-1 CO DO CO A3 o 1 Ln O 3 CD S3 3 a CD n rt p4 CO CO 4>* CO VO -p' 1“ * oo O DO Ln i 1—‘ O O 3 3 o (D d h— 1 rt O IP sc cn c *< 00 O) DO VO • -p* DO Ln • ■P* DO • VO i M Ln O 3 CO o o> LO 00 • CO d o CD d* < •"C d O OP d A3 3 d A3 3 w CO LO LO • VO OP A3 M d • sc CO SC CD A3 OP H* M M H* OP Ln i O 3 3 dl A3 M h-1 Ln s CD d* OP sr rt w II o 3 (0 r* A3 rt CD OP d c Ln h -* r* CO o o • o & o o 3 o> o> A3 d i- * —k dJ d DO DO • DO 1-* \l • OV 1-* 00 • vo H1 Ln i DO O O CO DO 3 . 1 -* DO 1 -* • 00 32 Table 17. Effects of fertilizer program s on fall rooting (1986). r* CO g cd 0) VO • VO m • VO rv vo • rv vo VO • i— i . as o m O O i— l CM VO • |v r—l • m ON • in CM • rv 00 CM • VO T— 1 r —i CM |v m VO rv rv O M •M CO U CD Q g bO o 4-> o • w CO cd 4J m on • VO O • rv ON • CX bO G vO G cd v t M l- VO ON • in O CM 00 CM • m •M i- l cd G cr 4J P i CO CD CM CO CD i— i m P cd 4J P bO 2 <3 *H i— i vo Cv o vo Cv rv VO CM CO a) o a cd bO i— i i— i G co *-) .— 1 v o G i- i P CM • VO •vi­ vo n ON • Cv m vo vo O CM • Cv 00 rv vo VO > oo CM • ON CM . VO 2 <3 i>N M •H i— l cd G p CO • vo vd• rv rv rv • VO • vO O CO • cr P l— l CD •H 4J CO ¡M P G •M bi II Q) cd S a ON M P • rv o • VO m O vo rv • • ON CO . <1Cv CO CM • m VO CM • rv rv CM v t vo rv rv ON v f • vo rv in in ON CM • rv • CM v t CO 00 <3 r—l vo l—l o s G CD CD t— l G cd a) u P i— i PQ • PM o cm G i— i P in o O 6 u o P CD G co CM G P CM O i— l CO • ON in ON • CM • vT in VO m rv in • CM CD T— l cd o CO cd X3 0 D C G o P CD CO cd >N o Cd S CM !h c 0 M •M r— l cd 3 CD 2 i— i o> T™ cr 0 ) Q 00 P CO M o i— 1 cd •H M a) Gm G i-i P • rO a) a> S ° G CO ° CM .Q CO u- cd 33 l— l cd •l-l s CD i— l O U u CD 4J cd cd G pQ cd CD u p CD P £ O CM CM 2 i—i P B u o P m o o Q CO p Clipping weights = grams/1.63 Table 19. 1987 visual quality and clipping yields for four liquid fertilizers. on CM • rv l— l O ' VO 4J a) oo CM • VO v j- G II CM • vJON v f rC o t— i p •M i— l CO ^ “N i— l C O G CM P a ON 00 -O Ln ON 00 ON oo CO d ON ON oo o ON Ln O d a o "■4 00 -F> ON 'O h-1 o ^4 ro Ln ON 00 4> ON ON 4> LO o ON vO ON ''O LO o Ln I- 1 o ON VO 00 Ln 'O ON h- 4 LO ^•4 H* 00 00 4> ON Ln ro ON \l NO -F> ON Ln LO Ln o a d \ I—4 r—* ON ON ON Ln O o VO VO 00 00 ^4 \ \ \ \ \ \ \ \ \ \ \ N ro o ro O ro h- 4 L0 H 4 L0 1—* o ro h- 4 ro 00 ON I- 4 I-» ON O Ln ro o 00 t- 4 ? M H* 6 oo 00 ON 'O o LO O 1P 1 I'd Ila |d 1It-* |d 1 Ln L0 'O O ON ON ^4 o L0 "*4 O o -*4 *^4 O Ln Ln ON Ln O ^4 O LO 'O ON Ln -O ^4 00 00 ON • o o L0 o ^4 \l ^4 'O 'O O O L0 —1 o \l Ln Ln 'O ON ON "*4 ON ^4 O L0 ^4 ^*4 L0 L0 o L0 ^4 o O O LO O L0 L0 L0 L0 -*4 —1 *^l O Ln ON ON ON ON ON ^1 L0 O 0° I a ^1 *0 -»4 L0 Ln ON Ln ON ON Ln ON ON * 1 ON ON VO ^*4 o ON ro M 1d 1a ON 00 LO 1 —1 d 1o ON -F> o ^ 1 d |la |d 1 lo L0 O -O ^4 O ON L0 'O L0 00 00 00 O O O "vj Ln L0 LO "«4 L0 L0 O a L0 \l L0 O -4 -O 00 L0 o "0 -vj "-J Ln ON ON • L0 O L0 1 !d |la 1 ila | 1 d 1a 1 |a -o ON ON Ln ON ON ON Ln ON ON \ l O L0 \1 *0 O 34 L0 \l ^4 O "«4 'O • LO O CO d n 3 rq d lo 1 ON Ln ON Ln ON ON ON Ln ON ON ON \ l ^ • ^4 L0 L0 L0 UJ a CD CD 11 L0 'v j L0 -O L0 "«4 a CD M D5 3 o CD a 11 11 'O O a d ltd ON ON Ln ON ON Ln Ln o O -o 'O O a la d la Ln ON "*4 ^4 00 L0 O Id |a a Ln ON 4> 1O ON VO Ln ON "O LO 4> LO ro o \i O O O O H-* M CD O Ct CD I1 Ln ON Ln ON ON ON ^4 ON Ln ^1 Ln L0 o 00 ■P* ^4 ^4 00 00 Ln ^4 L0 "O "O o LO ^4 L0 L0 ^4 o L0 L0 O P3 o P3 ct D) "«4 Ln ON Ln --4 Ln Ln ON ON ON ON ON ON \l o 1| < M* 0) 5 5 d I d o a CD Ct CD d CD M 1-* Table 20. The effects of cultivar, fertilizer program, and fertilizer material on quality and yield. -•4 00 4> ON 00 ^4 ON L0 4> n H* H* d d H* d ra 1 < H* CD 1—1 a a ____________________ Cultivar - Vantage_______________ ___________________________________________________ Programs___________________ 10/20 VO 00 'O ON Ln \ \ \ ro ro ro ro ro lo o I- 1 LO o \ Ol fa| i—II h| 4a;-> -I pQ| cd P -i | or^ocoor^r^cococor^oco ............................................ r^vovovovovoinvovomvor^vo Ol P^| o o c o o r^ r^ o o o o c o c o c o ............................................ r^Nvo^ovovor'si^r^vovovoin ¿1 c o o o o r ^ o r ^ o r ^ r ^ r ^ c o r ^ ........................................................................................ mr^inr^r^r^r^oovom vom ^f PQI pul o r -* m vo co < t o oo cm i- i o m m n vo h VO •H 4-> r—l 3 o CO vo vo o CO o CO CO CO £1 r^ in cm < f o oo oo vo oo i— i N vo vo co . m ¿1 h * vo CO VO CO < t vo oo ^ VO CO H o m m PQI P m| CO VO CO VO s f < f N O0 CO VO a> O VO VO CO 4 O OO H N 00 H CO vo O U fa > > cd Q) p o o o m m vo vo CO o CO CO r- CO vo vo in vo CO o o 00 CO r^* in vo CO O in •H p P *H iH U 6 bi C o o o c M i n o v O i —i i —i v o o o c s i r ^ i —i i—I C M O i—I C O i—I C O r —I C M O C M O C M W N W W W W W 10/20 T> vo a ii c n CD P> 13 to || a 0 i-* H‘ T3 td , H» P OO k H* CD M a W 13 O II t CL CD 00 K CD to M w c 0 CD '• 13 f H 13 M c ib 3 M p3 H* 1 o> \ l Ov OS 'O O L0 O LO 0 00 Ln 00 Ln av ON O LO 0 O 0 0 'O LO L0 O ON O 'O "O 'O \ l 00 ON LO LO \ l \ l ON ">J ON LO y 1 O 1I p g 13 ->J 1 If Ln I1 • LO L 1 1V—4 LO Di d a 13 | lo \ II 1 -4 13 O \ ra a P5 O 1b rt O M H* d d H* d H* PU k 00 vO OO '-J o n L n \ \ \ \ \ to to to to to 0 to LO 0 I -1 LO 0 0 • lb S CD H* h* \ Table 20. (continued) o on LO 3 to • cr CD to rt 00 0 O 00 Ln LO LO Ln * O O I a O I1 C 1 -4 •-Q Ln c pj 1-* H* rt 0 P* k "• O on Ln P P P Ln P p P vo to I - 4 00 Ln LO 00 VO p LO Ln ro I113 |ltd I113 1 If • L0 Ln Os O 'O \ l O Os On O O Ln ^1 Ov LO Ov Lo L0 OS 'O Ln L0 'O O L0 'O Ln o> Ln O ■^1 L0 0 00 00 0 ON Ln Ln \ l *^1 '-J O ON LO ON Ln ON 0 LO O ON 0 ON P ' • O I1 13 ltd | P' 13 LO If II P3 O O CD 'O 0 'O P P Ln P P L n I -4 L 0 to Ln I113 Il o LO I1 . O Ov ON '-J ON P' O LO LO LO 'O OS ON ON CD < < cn d i{ i 4* d rQ 13 lo CT M CD 1-* L n O n P to P P P Ln O 'O M la 1 Ln LO IN |ltd O ►Q P P) 0 Ln H* P P ON P P ON I-4 L 0 Ln Ln O O O O 0 00 00 Ln L0 O ON 'O 0 0 LO 00 -O • I Ln ON O • •^1 O I1 13 ltd | ON ON O 'O 0 ON 0 Ln a 1 Ln O P3 P ON P Ln on P P Ln to I - 4 LO Ld Ln 00 P P I-4 ON Ln I|13 |I f Os o> O Ln 'O O ON L0 0 L0 LO 0 LO 0 LO LO Ln Lo Ln O ON O | 13 LO f ON | a M P vO ON O 11 f rt CD rt k I|13 lo 1 av \ l -o Ln O •^1 O LO p 0 36 Ln ON ON ON O LO 13 O 1 13 P3 1 -4 1 -4 4* 13 < U d O rq 1 n D3 3 S to to _i. CD w rt H‘ O 13 rt rt a Fertilizer Burn Study M. L. Agnew and R. W. Moore The objective of this study was to compare the effects of three fertilizer sources and three water dilution rates on fertilizer burn on ’Manhattan’ perennial ryegrass. The three fertilizer sources include N-Sure, formolene, and urea. Each fertilizer source was diluted into 1, 2, and 4 gallons of water/1000 ft2. Each fertilizer/water dilution rate was applied to a 5’ X 5’ plot at a rate of 1 lb N/1000 ft2. The perennial ryegrass was maintained at a cutting height of 2 inches. Irrigation was applied as needed to prevent drought stress. Treatment were applied on June 10 and August 9,1987. A third application was scheduled for the spring of 1988. Data collected included visual quality 2, 4, and 8 days following treatment. In addition, shoot density was measured in July to test the effect of treatment on turf cover. Visual quality for this study is a measurement of discoloration due to fertilizer treatments (9 = no visual discoloration, 6.5 = acceptable quality, and 1 = dead turfgrass). Shoot den­ sity is the number of perennial ryegrass tillers in a given area. Table 21 provides the data of each of the treatments for both application periods. While there were no significant inter­ actions between fertilizer source and water volume within the study, there was a difference in the quality between fertilizer sources for both treatment dates and water volume for the June treatment. There were no treatment differences when measuring shoot density. In June, the N-Sure treatment demonstrated consistently better quality (less burn) than did formolene or urea. While N-Sure did have some burn, the quality never went below an ac­ ceptable quality level. In August, the effect of fertilizer source was less. This is due to cooler temperatures present during this time period (Table 22). The June data demonstrates that increased water volume decreases the amount of burn. This is to be expected since the fertilizer in solution would be more concentrated at lower water volumes. However, the August data does not show any treatment effects due to a 2.41 inch rain the night of August 9,1987, (Table 22). When looking at the June data, the degree of burn damage became worse over a period of time. During the 10 days following treatment, there were 6 days where the high tempera­ ture for that day reached 90F or higher. This demonstrates that care should be taken when applying fertilizers during stress periods. In summary, the use of N-Sure resulted in less fertilizer burn, and increasing water volume decreased the amount of fertilizer burn. Further study needs to be done to investigate fer­ tilizer rates and water volumes. 37 Table 21. The effects of fertilizer source and water volume on fertilizer burn Fertilizer Source Water Volume ________________ Visual Quality_____________ 6/14 6/16 6/20 8/11 8/13 8/17 Shoot Density Urea 1 2 4 4.3 6.7 7.0 4.0 5.7 6.0 5.0 5.6 6.3 7.7 7.7 8.3 6.3 6.7 6.7 7.7 7.7 7.3 155 159 177 N-Sure 1 2 4 7.3 8.0 8.3 6.7 7.3 7.7 6.7 6.7 7.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 174 176 181 Formolene 1 2 4 5.7 7.0 7.0 5.0 6.0 6.3 5.0 5.7 6.0 9.0 9.0 9.0 8.3 8.0 8.3 9.0 8.7 9.0 185 169 200 0.9 0.9 N.S. 0.9 0.9 N.S. 0.8 N.S. N.S. 0.3 N.S. N.S. 0.5 N.S. N.S. 0.4 N.S. N.S. N.S. N.S. N.S. LSD fert. (0.05) LSD water (0.05) LSD fert X water Table 22. W eather data collection at ISU Horticulture Station Turfgrass Research Area for June 12 to June 20 and August 9 to August 17,1987. High Date Low Precipitation (inches) (F) 6-12 6-13 6-14 6-15 6-16 6-17 6-18 6-19 6-20 95 99 99 89 90 90 89 90 76 60 62 68 70 64 67 69 68 68 0 0 0 0 0 0.55 0 0 0.39 8-09 8-10 8-11 8-12 8-13 8-14 8-15 8-16 8-17 85 86 84 78 77 84 89 85 80 62 62 65 66 70 76 69 67 62 2.41 0 0 0 0.87 0.16 0 0.16 0.08 38 Preemergence Crabgrass Control Study -1987 N. E. Christians, Z. J. Reicher, and M. G. Burt The 1987 preemergence crabgrass control study was located at the Horticulture Research Station on a Nicollet (fine-loamy, mixed mesic, Aquic Hapludall) soil with a pH of 7.2, 15 Ib/A phosphorus (p), 120 Ib/A potassium (K), and 2.3% organic matter. The grass on the site is Vantage Kentucky bluegrass. The treatments included EL-107, Balan, and Team from Elanco, Dacthaffrom Fermenta, ProdiamineTrom Sandoz Chemical, Pendimethalin from O. M. Scotts, Ronstar and DFF from Rhone Poulenc, Mon 15172 and 15126 from Monsanto, and Premier from CibaGeigy. The And-1,-2, and -3 are fertilizer herbicide combinations from The Anderson’s ComDany (see table 23 for treatment rates). Treatments were applied on April 16, 1987, to 25 ft2 plots in three replications. The area had a natural stand of crabgrass in the 1986 season. Crabgrass seed was applied to the area on April 20, at a rate of 0.5 lb/1000 ft2. Two-tenths of an inch of rain fell on the plot area within four hours after treatment. The 1987 season was unusually moist in the Ames area and there was little stress on the plot areas. The plot area was observed weekly through the season for phytotoxicity. No visible signs of phytotoxicity were observed on any of the treated plots at any time during the season. Estimates of crabgrass cover on the plots were made on July 15 and September 3 (Table 23). Counts of prostrate spurge also were made on September 3. The EL-107 combined with Balan and Team (Treatment 2, 3, and 4) were very effective at controlling crabgrass throughout the season, as was the Team 2G at 3 lb ai/A. The Mon 15172 was effective at season long control of crabgrass at all rates. The Mon 15126 was effective in controlling crabgrass all season long; however, the plots treated at the 0.5 lb rate of this material showed some increase in crabgrass numbers by September 3. The very moist conditions in mid-summer resulted in less than complete crabgrass controls by many of the other products including Dacthal, Prodiamine, Pendimethalin, and Ronstar G. The Ronstar 50 WP was effective in controlling crabgrass through the season. In past years, we have had some phytotoxicity with this product, but at the 1.5 lb ai/A rate in this trial no phytotoxicity was observed. The DFF experimental material was not effective at any of the rates tested. Complete prostrate spurge control was observed in plots treated with the EL-107, the Pendimethalin at the 3.0 lb ai/A rate (the 1.5 lb rate was not effective), and the Mon 15172. Table 24 contains information on a second trial conducted on the same sight. This study was designed to evaluate increasing rates of Ronstar 50 ME (micro encapsulated). This material was very effective at rates of 3.0 lb a.i. and above. 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Ronstar Trial -1987. • \ a; •l-l X cd cd Pi X X 1 1 1 1 m • o O m o X CO • o• o in • X X X UO i i i i >0 rP V-/ * w X P a) £ X cd < cd Postemergence Annual Grass Control Study -1987 Z. J. Reicher, N. E. Christians, and M. G. Burt The 1987 postemergence crabgrass control study was located at the Horticulture Research Station on a two-year-old stand of South Dakota Common Kentucky bluegrass. The soil on this site is a Nicollet (fine-loamy, mixed mesic, Aquic Hapludoll) with a pH of 7.2,15 Ib/A phosphorus, 120 Ib/A potassium, and 2.3 percent organic matter. Even though the site had a substantial crabgrass population, the area was vertical mowed and seeded with crabgrass at 0?5 lb seed/A prior to application. The crabgrass was al­ lowed to germinate and was in the 3-leaf to 1-tiller stage at the time of application. Treatments included American Hoechst’s Acclaim alone and in combination with prodiamine, pendimethalin, Turflon D, PBI Gordon’s Trimec, Starane, Lontrel (chopyralid), and The Anderson’s Break-Thru (chlorflurenol). Other treatments included a BASF ex­ perimental, BAS 51400H, and a Monsanto experimental, Mon 15126 in combinations with the spreader/sticker X77 and Acclaim. The herbicides were applied on June 2, 1987, in the equivalent of 120 gal water/A. The plots were checked weekly for phytotoxicity but there was none throughout the duration of the experiment. The first crabgrass count was taken on July 15,1987 (Table 25). The experimentáis from BASF and Monsanto had excellent control at all rates and in all combinations. In contrast to previous years, Acclaim showed inadequate control in all but a few combinations on the July 15 count. Only Acclaim in combination with pendimethalin, Starane, and chlorflurenol had 90 percent or better control. Only the Monsanto experimental, Mon-15126, in combinations with X77 and Acclaim had better than 90 percent control on the September 3 count. Mon-15126 at 0.75, 1.0, and 1.5 lb ai/A with 0.5 percent X77 showed excellent control as did the combination of Mon15126, Acclaim, and X77. The Acclaim plus pendimethalin plus X77 combination and Mon15126 at 0.5 lb ai/A with 0.5 percent X77 had 86 and 82 percent control, respectively, but the rest of the treatments had less than 80 percent control by September 3, which is below a satisfactory level. 42 4-> r —1 o P <1) u O u CO U p a) o U Pm a ■MB o X m o 00 oo vo CM o m CM m VO CM CO 00 CM CM co X 00 m X o vo oo CM m m CM m m CO CM X o CO o r - m CM CM m OO ON 00 00 ON 00 o 00 00 vo CM VO ON ON ON CO CO m r - 0 0 Ov ON ON ON o VO < f 00 CO rO e bO o XI Ü cd u CO X O m 00 VO CO CO VO in o CO X X o X m in CM X CM u o CJ c CD O ) ft. 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Phytotoxicity ratings and percent Poa annua infestation in treated areas. f O CO oo Table VO Preemergence Herbicide and Core Cultivation Study G. M. Peterson, M. L. Agnew, and N. E. Christians With the intense amount of traffic that athletic fields receive, there is intense pressure from crabgrass and knotweed invasion. Compacted soils on athletic fields also require core cul­ tivation in the spring. However, weather conditions may not allow cultivation prior to the ap­ plication of preemergence herbicides. Recent research suggests that core cultivation will not affect crabgrass germination. However, these studies were not aerified with the inten­ sity of that done on athletic fields. The purpose of this study was to determine the effectiveness of four preemergence herbicides when followed by three levels of cultivation. This study was established in the spring of 1987 on the Newton High School practice football field. This area was chosen for its high percentage of crabgrass and severe soil compaction conditions. The treatments include four preemergence herbicides and three cultivation treatments. The preemergence herbicides and rates are listed in table 36. The cultivation treatments were applied with a Ryan Lawn Aire IV. Treatments include 0, 2, and 4 passes with the aerator. Crabgrass populations were determined on July 23, 2987, (Table 36). There were no differences in crabgrass counts between cultivation treatments or herbicide/cultivator inter­ actions. There was, however, a difference in the effectiveness of herbicides. Team 2G at 2 lb ai/A, Dacthal and Prodiamine at 0.5 lb ai/A provided less crabgrass control than other herbicide treatments. This study will be repeated in 1988. 67 Table 36. The effect of core cultivation on the effectiveness of preem ergence herbicides. Crabgrass count Percent crabgrass control Herbicide Rate ai/A None ____ 0 2 4 233 227 227 0 0 0 2.0 0 2 4 33 17 51 85 92 77 3.0 0 2 4 10 14 15 96 94 94 10.5 0 2 4 41 36 20 82 84 91 Prodiamine 65WDG 0.5 0 2 4 37 28 23 84 88 90 Prodimaine 65WDG 0.75 0 2 4 17 6 6 92 98 98 Pendimethalin 60WDG 1.5 0 2 4 13 18 13 94 92 94 Pendimethalin 60WDG 3.0 0 2 4 2 1 3 99 99 98 15 6 Team 2G Core cultivation 1 Team 2G Dacthal 75WP LSD (0.05) (Herbicide) 68 Cultivation Intensity Study M. L. Agnew, N. E. Christians, and R. W. Moore In the spring of 1986, a cultivation study was initiated on two areas, a one-year-old stand of Midnight Kentucky bluegrass and a four-year-old stand of Premium Sod Blend. The pur­ pose of this study is to investigate the effects of core cultivation and grooving on thatch preventive and thatch removal. The turfgrass is maintained at a 2-inch mowing height with clippings returned to the soil. The area is fertilized with 4 lb N/1000 ft2/growing season using sulfur coated urea. Thatch depth was measured on May 23,1987. Measurements were taken by pulling a 6inch diameter core from each plot. The thatch was compressed using a 1 kg weight and the depth was measured in mm. Two 7.5 cm diameter samples of the thatch layer were collected, and dry and ash weights were determined. The organic component was calcu­ lated as the percentage of the thatch layer that is organic matter [dry wt - ash wt/ash wt) x 100]. Visual quality and weed counts were made on September 17,1987. Quality is based on a scale of 1 to 9, with 9 = best quality, 6 = acceptable quality, and 1 = dead turf. After one full year of treatments, compressed thatch depth was measured on May 23, 1987. For Midnight Kentucky bluegrass, only grooving on May, September, and on May, July, September reduced or prevented an accumulation of thatch (Table 37) while there was no difference in thatch accumulation in Premium Sod Blend (Table 38). Quality ratings were affected by treatments for both turfgrass areas. It should be noted that the grooving treatment was more severe than what normally would have been used. The intent was to remove thatch, unfortunately, the turfgrass was severely thinned. By the spring of 1988, the turfgrass in the grooved areas had not filled back in completely. Thatch determination will be done in May 1988. Grooving decreased the quality of Midnight Ken­ tucky bluegrass by as much as 50 percent (Table 39) and Premium Sod Blend by as much as 30 percent (Table 40). Multiple groovings decreased quality the most. In addition, grooving caused an increase in weed invasion. 69 Table 37. Effects of cultivation equipment and timing of application on thatch development of Midnight Kentucky bluegrass. Cultivation equipment Dates of applicationa None Core Core Core Core aeration aeration aeration aeration Grooving Grooving Grooving Grooving LSD Thatch depth (mm) Organic component^ (percent) Thatch accumulation0 (mm) None 23.3 30.2 8.3 M S M, S M, J, S 22.8 23.7 22.0 23.7 28.2 30.5 35.0 36.1 4.4 5.3 8.7 3.7 M S M, S M, J, S 22.4 21.4 20.1 18.2 31.7 32.0 31.5 28.4 7.4 3.1 0.1 -0.1 2.8 N.S. 5.8 0.05 a M = May, J = July, S — September. k Organic component is the percentage of the thatch layer that is organic matter. The remaining portion of the thatch layer is made up of soil. c Thatch accumulation is the thatch depth on May 23, 1987, less the original thatch depth. Table 38. Effects of cultivation equipment and timing of application on thatch developm ent of Premium Sod Blend Kentucky bluegrass. Cultivation equipment Dates of applicationa None Core Core Core Core aeration aeration aeration aeration Grooving Grooving Grooving Grooving LSD 0.05 Thatch depth (mm) Organic component^ (percent) None 23.3 24.7 2.3 M S M, S M, J, S 26.2 27.7 30.7 22.7 26.4 38.0 30.5 25.7 3.8 -0.7 4.0 -0.7 M S M, S M, J, 27.2 26.3 27.8 26.8 24.6 28.8 28.4 26.0 3.8 -3.7 N.S. N.S. s Thatch accumulation0 (mm) 1.1 1.4 N.S. a M *= May, J * July, S - September. k Organic component is the percentage of the thatch layer that is organic matter. The remaining portion of the thatch layer is made up of soil. c Thatch accumulation is the thatch depth on May 23, 1987, less the original thatch depth. 70 Table 39. Effects of cultivation equipment and timing of application on quality and weed invasion of Midnight Kentucky bluegrass. (9/17/87) Grass Weeds Broadleaf Weeds 9.0 0.0 0.0 Mc S M, S M, J, S 9.0 9.0 9.0 9.0 0.0 0.0 0.7 0.0 0.0 0.0 0.0 0.0 M S M, s M, J, s 8.7 5.3 5.3 4.3 8.7 0.0 5.7 9.7 6.0 0.0 11.7 9.3 0.9 5.4 9.7 Cultivation equipment Dates of application3 None None Core Core Core Core aeration aeration aeration aeration Grooving Grooving Grooving Grooving LSD Visual quality*5 0.05 a M — May, J = July, S » September. k Visual quality was rated on a scale of 1 to 9, with 9 = best quality, 6.0 as the minimum acceptable level, and 1 = dead turf. c Thatch accumulation is the thatch depth on May 23, 1987, less the original thatch depth. Table 40. Effects of cultivation equipment and timing of application on quality and w eed invasion of Premium Sod Blend Kentucky bluegrass. (9/17/87) Cultivation equipment Dates of application3 None None Core Core Core Core aeration aeration aeration aeration Grooving Grooving Grooving Grooving LSD Visual quality*5 Grass weeds Broadleaf weeds 8.0 0.0 0.0 Mc S M, S M, J, S 8.0 8.0 7.7 8.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 M S M, S M, J, S 5.3 8.0 6.3 5.7 1.3 0.0 1.0 0.3 9.3 0.0 5.7 3.3 1.1 N.S. 5.4 0.05 3 M = May, J = July, S = September. D Visual quality was rated on a scale of 1 to 9, with 9 = best quality, 6.0 as the minimum acceptable level, and 1 = dead turf. c Thatch accumulation is the thatch depth on May 23, 1987, less the original thatch depth. 71 Summer Stress Survival Study of Kentucky Bluegrass Cultivars M. G. Burt and N. E. Christians Kentucky bluegrass (Poa p r a t e n s is L.) cultivars are known to vary in their response to environmental stresses and cultural practices. Great variability has been observed over many seasons in the USDA Kentucky bluegrass cultivar evaluations at the Iowa State University Horticulture Station. The low-maintenance Kentucky bluegrass cultivar evalua­ tion was established in September 1980. It receives a September application of 1 lb N/1000 fr/y r and is nonirrigated. The high-maintenance cultivar evaluation was estab­ lished in August 1981, and this area receives 4 lb N/1000 ft2/yr and supplemental irrigation as needed. The most recent Kentucky bluegrass cultivar evaluation was established in August 1985. This area receives 4 lb N/1000 ft2/yr and is nonirrigated. The first data were collected from this cultivar trial during the 1987 growing season. Data from these three tri­ als are summarized in the annual Io w a T u rfg ra s s R e s e a r c h R e p o rt. The past data show the Kentucky bluegrass cultivars that perform well in the low-main­ tenance cultivar evaluation tend to perform poorly in the high-maintenance cultivar evalua­ tion. Likewise, the Kentucky bluegrass cultivars that perform well in the high-maintenance cultivar evaluation tend to perform poorly in the low-maintenance cultivar trial. Five Ken­ tucky bluegrass cultivars were chosen that have consistently performed well in the lowmaintenance trial. These ’low-maintenance’ cultivars are K3-162, Kenblue, Vantage, S. D. Common, and S-21. Conversely, five cultivars were chosen that consistently perform poor­ ly in the low-maintenance trial. These ’high-maintenance’ cultivars are Bonnieblue, A20, Columbia, Lovegreen, and 1-13. These ten cultivars will be used throughout this research, and seed of these cultivars was obtained from the USDA National Turfgrass Evaluation Program. The objectives of this research are: 1) to determine if certain root, shoot, and growth characteristics are common to cultivars grouped in the high- or low-maintenance classifica­ tion. 2) To simulate drought conditions in the greenhouse and to monitor the cultivars’ response to and recovery from this imposed water stress. 3) To relate information from this and the research of others to Kentucky bluegrass cultivar response to environmental stresses and cultural practices as a means to explain why these cultivars perform as they do. The Kentucky bluegrass characterization studies will be done using field data, greenhouse studies, and microscope techniques. All field data will be collected from the low-main­ tenance cultivar trial. The greenhouse experiments use a clear polyethylene tube in PVC pipe system to closely monitor root and shoot growth of individual Kentucky bluegrass cul­ tivar seedlings grown for 10 to 12 weeks in a fritted clay media plus slow release fertilizer. The microscope study will characterize the Kentucky bluegrass cultivars by looking specific­ ally at leaf stomatal distribution and number. The microscope also will be used to study Kentucky bluegrass crown tissue that has been subjected to water stress to try to deter­ mine what may be common to crown tissue that survives prolonged drought conditions. 72 The greenhouse drought simulation study will use a modification of the polyethylene tube in PVC pipe system. The slow drying fritted clay has been replaced by a medium-fine sand, and required plant nutrients are supplied by a plant nutrient solution. Kentucky bluegrass seedlings are grown in the tubes until they are well-tillered and deeply rooted. Water will be withheld for various lengths of time and response to and recovery from this imposed water stress will be monitored and recorded. No data has been analyzed yet from the greenhouse drought simulation study. However, preliminary experimentation shows fairly even drying and recovery of the Kentucky bluegrass plants grown in these sand columns. Likewise, no data have been generated from the microscope work. The greenhouse characterization study has yielded some inter­ esting results, the low-maintenance cultivars have significantly narrower leaves and more leaf folding, longer sheaths, less leaf angle from vertical, and fewer leaves per tiller. The low-maintenance cultivars had significantly greater weekly clipping weights. The low-main­ tenance cultivars had a greater percentage of their fresh weight as dry weight. This indi­ cates that the low-maintenance cultivars hold proportionally less water in their tissues. The low-maintenance cultivars had a lower shoot to root ratio. The low-maintenance cultivars had greater total root weights in all three experiments. The high-maintenance cultivars had a significantly greater percentage of their total root weight in the top seven inches of the root profile, whereas the low-maintenance cultivars had a significantly greater percentage of their total root weight in the 7 to 14 inch section of the root profiles. Little rooting oc­ curred in the 14 to 21 inch section of the root profiles, so significant rooting differences were not found. The low-maintenance cultivars also tended to root deeper. Even though the tillering data was quite variable, the low-maintenance cultivars generally produced more tillers. This preliminary data indicate that certain Kentucky bluegrass cultivars may possess adaptations that enable them to better tolerate low-maintenance culture. Subsequent re­ search may generate more data to further substantiate the variability that exists between cultivars, and this research could help to explain why such variability occurs. 73 Comparative Effectiveness of Insecticides Against Annual White Grubs -1987 D. L. Lewis and N. E. Christians Damage to turfgrass by annual white grubs ( ys C pp.) is a com and locally severe problem in Iowa. Amount of damage varies greatly from place to place and from year to year, depending on several factors such as grass variety, cultural main­ tenance practices, irrigation, and weather. Root feeding by these masked chafer larvae characteristically causes grass to wilt, turn tan, and finally die, usually in late August or early September. Several granular and emulsifiable concentrate insecticide products are registered for white grub control. Timing of insecticide application is very important in achieving effective control of white grubs before damage becomes severe. The objective of this study was to evaluate and compare the efficacy of several registered and experimental insecticides against annual white grubs infesting turfgrass. The study was conducted on a rough area of the Hyperion Golf and Country Club located in Johnston, Iowa (Polk County). The soil at the Club is a Waukegan loam (fine-silty over sandy, mixed, mesic typic hapludoll) with 148 Ib/A P, 480 Ib/A K, and 5 percent organic matter. The plots were at the crest of an east-facing slope. The grass species in the plots was Kentucky bluegrass. The rough was receiving low maintenance but regular mowing (at approximately 3 inches) and irrigation as necessary. There was between 1/4 and 1/2 inch of thatch at the test site. Grub damage was apparent throughout the plot vicinity at the time of insecticide application. The insecticide treatments were applied on August 18, 1987. A second ap­ plication of Diazinon AG500 and Diazinon 14G (the ’split’ treatments) was applied a week later on August 26. Grub population counts were made September 10,1987. The experimental design consisted of 13 treatment plots and one untreated check plot, randomly assigned in each of three replications. Each plot consisted of a 5 ft by 5 ft area (25 square feet). All insecticides were applied at the rate specified on the manufacturer’s label or product guidelines. Liquid insecticides were applied with a compressed gas, back­ pack sprayer, connected to a hand-held, three-nozzle boom. The boom covered a 5-foot wide area, and diluted insecticide spray was applied to the test plots with alternating per­ pendicular passes over the treatment plot. The amount of water applied to each plot was the equivalent of 175 gal/A. Granular insecticides were premeasured into round, cardboard containers and applied uniformly over the plot by shaking through a perforated lid. The insecticides were watered into the turfgrass immediately after the first application with approximately 1/2 inch of irrigation. The ’split’ treatment applications were applied during a light rain that continued to fall after the applications. 74 Annual white grub population counts were made three weeks after treatment by randomly selecting four 6-inch square sample sites within each plot, cutting the sample with a sharp knife, removing the sod, and counting all live white grubs found. The sod was lifted from the cut area, and the root mass carefully cut apart and examined for living grubs. The soil beneath the cut sod was scratched loose to a depth of two inches and similarly examined. The total number of white grubs found in each sample was recorded. Population counts in the samples were converted to number of white grubs per square foot for analysis and reporting. Population counts in the samples were converted to number of white grubs per square foot for analysis and reporting. The insecticides used in this project, the formulation, rate of application, and mean number of white grubs per square foot are given in table 41. Significant differences among treat­ ments and between treatments and the untreated check were determined by analysis of variance. In five years of conducting white grub insecticide screening trials, this was our best study. The study site was ideal in that a large, uniform population of white grubs was present over a sufficiently large area. The treatments were applied without difficulty and watering (both natural and irrigation) was timely and plentiful. The average population density in the untreated check plots was 27 white grubs per square foot. This exceeds population density thresholds sufficient to cause damage in ir­ rigated, healthy turfgrass. The ANOVA analysis reported in table 41 shows the Dursban products did not significantly reduce grub populations. This is in contrast to results of a similar trial conducted at this golf course last year when the Dursban 4E and ME formula­ tions were effective at both 0.5- and 1.0-lb rates. However, poor performance of Dursban for grub control is a common complaint within the turfgrass industry. ’Low’ rates of Turcam in both the wettable powder and granular formulations (2.0 and 2.1 lb ai/A, respective­ ly) did not significantly reduce grub populations, but the ’high’ rate of the granular product did. Casual observations of poor performance by Turcam have been reported and Turcam was not effective in our 1986 study. It is uncertain what this indicates, other than that fur­ ther experimentation and pooling of observations is needed. Several of the treatments did cause significant reductions in white grub numbers in the treatment plots compared to the check plots. Both diazinon formulations (AG500 and 14G) in both the regular and ’split’ treatments produced significant grub reduction. The single application, high rate, diazinon plots had fewer grubs, but the control was not significantly better than in the plots receiving two treatments at the lower rate. The top performing com­ pounds in this study were Diazinon AG500, Mocap 5G, and Triumph 4E. 75 Table 41. Effects of commercially available insecticides on annual white grubs infesting turfgrass, Polk County, Iowa, 1987. Insecticide / Formulation Control Dursban 4E Dursban ME Turcam 2.5G Dursban ME Turcam 76WP Diazinon AG500 'Split' Turcam 2.5G Diazinon 14G 'Split' Oftanol 2E Diazinon 14G Diazinon AG500 Mocap 5G Triumph 4E * Rate lb ai/A Mean number white grubs per square foot ___ 1.0 0.5 2.0 1.0 2.1 2.0 (each application) 4.0 2.0 (each application) 2.0 4.0 4.0 5.0 2.0 Treatment dates all products second application in 'split' treatments Population count date - August 18, 1987 August 26, 1987 September 10, 1987 76 27 25 22 18 17 17 10 7 7 6 5 2 2 2 A A A A A A B B B B B C C C C C C C C D D D D D D D D Evaluation of Fungicides for Control of Brown Patch on Bentgrass -1987 M. L. Gleason Trials were conducted on a bentgrass green at Veenker Memorial Golf Course of Iowa State University, Ames, Iowa. Fungicides were applied to bentgrass maintained at a 5/32inch 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 block plan with four replications. The plots measured 4 ft by 5 ft. Fungicides were applied in a 7-, 14-, 21-, or 28-day schedule (Table 42). Applications began on June 5 and continued through August 23. Plots were evaluated for percent of diseased turf on August 15, the only time during the summer when brown patch was evident. Brown patch development on August 15 was slight to moderate on check plots. A few of the treatments had very slight brown patch evident, but none of the chemical treatments was significantly different from any of the others, and all chemical treatments had sig­ nificantly less brown patch than the checks. All plots treated with PP 523 showed en­ hanced green color throughout July and August. No other treatments showed any evidence of phytotoxicity. 77 Table 42. Evaluation of fungicides for control of brown patch in bentgrass. Treatment Rate/ 1000 ft2 Check PP523 0.5 SC/surfactant PP523 0.5 SC/surfactant PP523 0.5 SC/surfactant PP523 10% WG/surfactant PP523 10% WG/surfactant PP523 10% WG/surfactant Apache 50WP Apache 50WP Apache 50WP Apache 50WP Apache 50WP/ Vorlan 50WP Apache 50WP/ Vorlan 50WP Apache 50WP/ Vorlan 50WP Fungo 50WP/ Vorlan 50WP Fungo 50WP Vorlan 50WP Fungo 50WP Banner 1.IE SN84364 50WP/surfactant SN84364 50WP/surfactant HWG 1608 1.2EC HWG 1608 1.2EC ___ 4 g a.i. 6 g a.i. 8 g a.i. 4 g a.i. 6 g a.i. 8 g a.i. 1 oz 2 oz 3 oz 3 oz 1 oz/ 1 oz 2 oz/ 2 oz 2 oz/ 2 oz 1 oz/ 1 oz 2 oz/ 2 oz 2 oz 1 oz 2 oz 4 oz 0.375 oz a.i. 0.375 oz a.i. 0.125 oz a.i. 0.125 oz a.i. 0.5 oz a.i. 1.0 g a.i. 1.5 g a.i. 2.0 g a.i. 2.5 g a.i. 3.0 g a.i. 1.0 g a.i. 3 oz 4 oz 1 oz/ 1 oz/ 2.5 oz 1 oz 2.5 oz Bayleton 1.0%G Rizolex 75WP Rizolex 75WP Rizolex 75WP Rizolex 75WP Rizolex 75WP Chipco 26019 50WP Chipco 26019 FLO Chipco 26019 FLO Caddy/ 3336/ Spotrete Caddy Spotrete Timing (days) _ 14 14 14 14 14 14 14 14 14 21 14 Disease Ratingsa (August 15) 1.25 0 0 0 0 0 0 0 0 0 0 0 a b b b b b b b b b b b 14 0 b 21 0 b 14 0 b 14 0 b 14 14 21 21 28 day 1 day 1 + 14 day 1 + 44 28 14 15 14 14 14 14 21 21 7 7 7 0 0.25 0 0 0 0 b b b b b b 0.25 0.25 0 0 0 0 0 0 0 0 b b b b b b b b b b 0 0 b b a Rating represents mean of disease severity ratings. 1 = light ; 2 = moderate 3 - severe. Means adjacent to the same letter do not differ significantly (DMRT, P=0.05) 78 Evaluation of Fungicides for Control of Foliar Diseases on Park Bluegrass -1987 M. L. Gleason Trials were conducted on the Turfgrass Research Plots at the Horticulture Research Station of Iowa State University near Ames, Iowa. Fungicides were applied to Park bluegrass maintained at a 1-1 /2-inch cutting height with a modified bicycle sprayer at 30 psi and a dilution rate of 5 gal/1000 ft2. The experimental design was a randomized block plan with four replications. Plots measured 4 ft by 5 ft. Fungicides were applied on a 14- or 21day schedule (Table 43). Applications began on June 3 and continued through August 23. Plots were evaluated for percent diseased turf on July 29 and August 27. This trial was set up, and fungicides were selected, for control of B ip o la r is leaf spot. However, no leaf spot was detectable all season. Instead, dollar spot was present at low levels. Consequently, development of dollar spot, not leaf spot, was rated. No plots showed phytotoxicity symptoms. However, dollar spot pressure was so low that conspicuous infection centers did not develop. Although two chemical treatments had sig­ nificantly lower dollar spot ratings than the check in statistical tests, these differences are probably too small to be definitive. 79 Table 43. Evaluation of fungicides for control of dollar spot in Park bluegrass, 1987. Treatment Check Prochloroz 40EC Prochloroz-MN 50WP FBC 39865 25WP FBC 39865 25WP Banner 1.1E Banner 1.IE Dyrene 4F Chipco 26019 FLO Chipco 26019 FLO Spotless 25U/surfactant Spotless 25U/surfactant Spotless 25U Spotless 25U Caddy/ 3336/ Spotrete Caddy Spotrete Nustar 20% DF Nustar 20% DF Rate/1000 ft^ Timing (days) 1.5 0.5 0.75 0.75 0.75 0.75 0.75 0.75 0.5 0.5 0.25 a a a a a a a a a a R a tin g s ^ August 27 14 14 14 14 14 14 14 21 21 14 30 14 30 7 1.0 a 0.75 a 1.0 a 0.75 a c c c c c c c c c c c c c c a b a b b a b a b a b b 1.0 a b 0.5 a b 1.0 a b 0.5 a b 0.75 a b 0.75 a b 0.75 a b 1.0 a b 7 7 14 14 1.25 a b 1.0 a b c 0 c 0.5 a b 1.25 a 1.0 a b 0.5 a b 0.5 a b - - 4.5 oz 3.75 oz 0.5 oz 1 oz 2 oz 3 oz 4 oz 3 oz 4 oz 0.4 oz 0.4 oz 0.4 oz 0.4 oz 1 oz/ 1 oz/ 2.5 oz 1 oz 2.5 oz 0.125 oz a.i. 0.25 oz a.i. Disease July 17 b b b b b b b b b b b b b b 0.75 0.75 0.25 0.75 0.75 0.75 0.25 a Fungicides were selected to test efficacy against another disease, Bipolaris leaf spot. However, leaf spot did not appear in these trials. Instead, infection by dollar spot was evaluated. k Average of ratings from four replicated plots. Based on the following rating scheme: 0 = no disease; 1 * trace only; 2 = slight disease; 3 = moderate disease; 4 = severe disease. 80 Supplementary Evaluation of Fungicides for Eradication of Dollar Spot on Bentgrass -1987 M. L. Gleason Trials were conducted on a bentgrass green at the Veenker Memorial Golf Course adjacent to Iowa State University, Ames, Iowa. Fungicides were applied to bentgrass main­ tained at a 5/32-inch cutting height, using a modified bicycle sprayer at 30 psi and a dilu­ tion rate of 5 gal/1000 ft2. The experimental design was a randomized block plan with four replications. The plots measured 4 ft by 5 ft. Fungicides were applied in a 7-, 14-, 21-, or 28-day schedule. Applications began on June 5 and continued through August 23. This trial was designed, and fungicides were selected, to evaluate efficacy in controlling B r o w n p a t c h . Data on control of brown patch during this trial are reported in Table 42. However, a moderate to severe outbreak of dollar spot existed on the site immediately prior to the start of the spray schedule (June 5). Dollar spot development was rated on all plots on June 5 and again on June 25. The number of dollar spot infection centers per plot was counted on both dates. The ability of the treatments to eradicate the dollar spot out­ break was estimated as percent reduction in number of infection centers between the two dates. That is, percent reduction = (number of infection centers on June 5 - number of in­ fection centers on June 25)/number of infection centers on June 5. Several chemical treatments did not reduce dollar spot significantly more than in check plots (Table 44). These treatments included: SN 84364 50WP at two different rates; HWG 1608 1.2EC at 0.375 oz a.i./1000 ft2; Fungo 50WP (1 oz/1000 ft2) plus Vorlan 50WP (1 oz/1000 ft2), Rizolex 75WP (2 g a.i./1000 ft2; Apache 50WP, 3 oz rate, at 14- and 21-day spray intervals; Apache 50WP (1 oz) plus Vorlan 50WP (1 oz); and PP523 10% WG at 6 g a.i./1000 ft2. All other treatments reduced dollar spot as compared to the check plots. 81 Table 44. Eradication of dollar spot outbreak in bentgrass.3 Treatment Check PP523 0.5 SC/surfactant PP523 0.5 SC/surfactant PP523 0.5 SC/surfactant PP523 10% WG/surfactant PP523 10% WG/surfactant PP523 10% WG/surfactant Apache 50WP Apache 50WP Apache 50WP Apache 50WP Apache 50WP/ Vorlan 50WP Apache 50WP/ Vorlan 50WP Apache 50WP/ Vorlan 50WP Fungo 50WP/ Vorlan 50WP Fungo 50WP/ Vorlan 50WP Fungo 50WP Banner 1.IE SN 84364 50WP/surfactant SN 84364 50WP/surfactant HWG 1608 1.2EC HWG 1608 1.2EC Bayleton 1.0%G Rizolex 75WP Rizolex 75WP Rizolex 75WP Rizolex 75WP Rizolex 75WP Chipco 26019 50WP Chipco 26019 FLO Chipco 26019 FLO Caddy/ 3336/ Spotrete Caddy Spotrete Rate/1000 ft^ _ 4 6 8 4 6 8 1 2 3 3 1 1 2 2 2 2 1 1 2 2 2 1 2 4 g a.i. g a.i. g a.i. g a.i. g a.i. g a.i. oz oz oz oz oz/ oz oz/ oz oz/ oz oz/ oz oz/ oz oz oz oz oz 0 ..375 oz a.i. 0 ..375 oz a.i. 0..125 oz a.i. 0 ..125 oz a.i. 0 ..5 oz a.i. 1,.0 g a.i. 1 .5 g a.i. 2 .0 g a.i. 2 .5 g a.i. 3 .0 g a.i. 1 .0 g a.i 3 OZ 4 oz 1 oz/ 1 oz/ 2 .5 oz 1 oz 2 .5 oz Timing (Days) Percent reduction in disease _ 14 14 14 14 14 14 14 14 14 21 14 12.7 97.5 97.8 93.4 93.7 67.2 89.3 87.1 71.9 65.0 67.0 60.9 a a a a a a a a a a a 14 90.4 a 21 87.1 a b 14 44.4 a 14 91.5 a 95.2 14 75.2 14 45.6 21 7.7 21 29.1 28 98.1 day 1 day 1+14 day 1+44 28 71.5 83.0 14 81.4 14 57.0 14 90.5 14 74.4 14 14 96.5 99.4 21 100.0 21 97.6 7 a a a 88.1 90.8 a a 7 7 d e b c d b b b b b c c c c d d d e b c d e b b c c d b c d e e e b b b b c d e b c a a a a a a a a a a a c a Fungicides in this trial were selected to test efficacy in controlling brown patch rather than dollar spot. However, an outbreak of dollar spot before the spray program began provided an opportunity to evaluate the ability of these fungicides to eradicate dollar spot. Data on control of brown patch are reported in able 42. 82 Evaluation of Fungicides for Control of Fairy Ring on Bluegrass -1987 M. L. Gleason Trials were conducted on a fairy ring, approximately 40 feet in diameter, located in a bluegrass rough at the Veenker Memorial Golf Course adjacent to Iowa State University, Ames, Iowa. The species of fungus causing the fairy ring was not identified. The ring was subdivided into plots measuring 5 ft by 5 ft. The experimental design was a randomized block plan with three replications. Before fungicides were applied, all plots were thoroughly pierced with pitchforks to a depth of at least 6 inches. Fungicides were applied on June 30, as drenches with recommended amounts of water, from watering cans. The check plots received comparable amounts of water. On June 30 and again on September 22, the radius of the ring was measured as the distance between a point at the center of the ring and the outer perimeter of the ring. Three radial measurements were made within each plot. Growth of the ring within each plot was calculated as the change in the mean radius between June 30 and September 22. None of the chemical treatments were effective in reducing growth of the ring significantly in comparison to untreated plots (Table 45). In fact, all treatments showed somewhat greater ring expansion than the check, although this difference was not statistically sig­ nificant. ■ Treatment Check Apache 50WP SN 84364 50WP/surfactantc SN 84364 50WP/surfactantc Rate 16 oz/50 gal water/100ft2 6 oz/1000ft2 10 oz/10002 ■ ■ W ■■ ■■ m v« W ■V«W Growth of ring finchl3 12.7 a 16.3 a 22.0 a 17.8 a a Numbers are mean change in radius of ring between June 30 and September 22. Means adjacecent to the same letter do not differ significantly (DMRT, P = 0.05). b Check plots received 24 gallons of water/100 ft2 on June 30. c SN 84364 treatments were diluted with 24 gallons of water/100ft2 when applied on June 30. 83 ■ Evaluation of Fungicides for Control of Dollar Spot in Emerald Bentgrass -1987 M. L. Gleason Trials were conducted on the Turfgrass Research Plots at the Horticulture Research Station of Iowa State University near Ames, Iowa. Fungicides were applied to Emerald bentgrass, maintained at a 5/32-inch cutting height, with a modified bicycle sprayer at 30 psi and a dilution rate of 5 gal/1000 ft2. The experimental design was a randomized block design with four replications. The plots measured 4 ft by 5 ft. Fungicides were applied in a 14-, 21-, or 28-day schedule (Table 46). Applications began on June 5 and continued through August 23. Plots were evaluated for percent diseased turf on July 17 and August 27. Disease ratings for dollar spot were made by counting the number of dollar spot infection centers per plot. Disease development was very slight throughout the season, even in the check plots, although it gradually increased as the season advanced (Table 46). Most treatments had no disease throughout the season. On August 27, plots treated with Chipco 26019 FLO at 3 oz/1000 ft2 had significantly more dollar spots than all other plots, in­ cluding the checks. The same chemical at the 4 oz rate gave significantly more infection centers than all plots except the check. There were no symptoms of phytotoxicity with any of the materials tested. 84 Table 46. Evaluation of fungicides for control of dollar spot in Emerald ____________ bentqrass, 1987.__________________________________________________ Treatment Check Banner 1.IE Banner 1.IE Prochloraz 40EC Prochloraz-MN 50WP Prochloraz-MN 50WP Prochloraz 40EC/ SN596 25DF SN596 25DF FBC 39865 25WP FBC 39865 25WP HWG 1608 1.2EC HWG 1608 1.2EC Bayleton 1%G Chipco 26019 FLO Chipco 26019 FLO Spotless 25U/surfactant Spotless 25U/surfactant Caddy/ 3336/ Spotrete Caddy Spotrete Disease Ratings^ August 27 July 17 Rate/ 1000 ft2 Timing (days) _ _ 21 21 21 21 21 21 2.00 0.25 0.50 1.25 0.50 0.50 1.75 a a a a a a a 2.00 0 0 0 0 0.25 0 21 21 21 28 28 28 21 21 14 28 7 2.25 0 0 0 0 0 0 0.25 0 0 0 a a a a a a a a a a a 0 0 0 0 0 0 7.25 5:25 0 0.25 0 7 7 0 2.25 a a 0 0 1 OZ 2 oz 4.5 oz 3.75 oz 4.5 oz 1.5 oz/ 0.5 oz 0.5 oz 1.0 oz 0.5 oz 0.125 oz a.i. 0.25 oz a.i. 0.25 oz a.i. 3 oz 4 oz 0.4 oz 0.4 oz 1 oz/ 1 oz/ 2.5 oz 1 oz 2.5 oz b c c c c c c c c c c a a b a Average of ratings from four replicated plots. Based on number of dollar spot infection centers per plot. Means in a column followed by the same letter do not differ significantly. 85 c c c c c c c Effect of Endophyte Infection of Perennial Ryegrass on Growth Under Drought Stress M. L. Gleason, N. C. Christians, and M. L. Agnew Cultivars of perennial ryegrass (L o liu m p e r e n n e ) with a high level of infection by an endophytic fungus ( A c r e m o n iu m lo lia e ) have been promoted by seed companies as being resistant to insect feeding and to "environmental stress." However, there is little experimen­ tal evidence to support the claim that high-endophyte cultivars perform better under "en­ vironmental stress" than low-endophyte cultivars. A project was initiated at Iowa State University in 1986 to evaluate the role of endophyte infection in tolerance to drought stress. A grant from the Iowa Turfgrass Institute supported this research. Populations of endophyte-infected and endophyte-free perennial ryegrass plants for this study were derived from the same clones in order to minimize genetic variability among plants. To obtain endophyte-infected and endophyte-free plants, tillers derived from the same mother plants were potted separately. Half of the tillers were treated with a benomyl drench for eight weeks in order to eliminate the endophyte, while the other half of the tillers received no benomyl. This method produced same-clonal plants with or without en­ dophyte. Plants originally derived from four mother plants were then potted in sandy loam soil amended with 5 g/l of Osmocote 14-14-14. The experiment was conducted in a green­ house during fall 1986, using the cultivar Repelí, and repeated in spring 1987, using Man­ hattan lie. Clones were derived from four mother plants for each experiment. Watering treatments corresponded to wet (-0.4 to -0.6 bars), moist (-2.1 to -2.6 bars), or dry (ap­ proximately -16 to -20 bars). Each pot was weighed daily, and watered to saturation when it had dried to a weight corresponding to the bar value of the relevant treatment. After 7-1/2 weeks, plants were washed free of soil, and number of tillers and dry weight of roots, stems, and live and dead blades was measured for all plants. Results are presented in Table 47. In Experiment 1, growth of endophyte-free and endophyte-infected plants was not significantly different at any of the soil moisture treat­ ments. In Experiment 2, however, dry weights of endophyte-free plants were significantly higher than for endophyte-infected plants for all moisture treatments. This result suggests that, under the conditions tested, endophyte infection hindered rather than increased growth of Manhattan lie over a wide range of soil moisture availability. The experiment will be repeated a third time, using the cultivar Manhattan lie, during summer 1988. 86 Table 47. Growth of endophyte-infected and endophyte-free perenial ryegrass at three levels of soil moisture availability. EXPERIMENT la MEAN DRY WEIGHTS (g) PER PLANTb Soil water potential (-bars) number of tillers^ stems roots live leaves dead leaves total live aboveground biomass total live biomass 0.4 freec infect^ 30.2 30.2 0.64 0.62 0.92 0.88 1.00 1.03 0.20 0.15 1.64 1.65 2.56 2.53 2.6 free infect 29.4 25.5 0.60 0.54 0.70 0.71 0.95 0.91 0.18 0.15 1.54 1.45 2.25 2.16 free infect 25.6 27.3 0.50 0.52 0.60 0.68 0.93 0.90 0.11 0.14 1.43 1.42 2.03 2.10 3.9 0.08 0.13 0.14 0.04 0.20 0.28 20e LSD (0.05) EXPERIMENT 2f 0.6 free infect 98.2 88.2 2.90 2.27 1.84 1.26 4.04 3.04 NSê NS 6.95 5.31 8.79 6.57 2.1 free infect 90.7 91.9 2.76 1.97 1.72 1.05 3.91 2.80 NS NS 6.67 4.77 8.39 5.82 free infect 79.3 79.1 1.88 1.37 0.98 0.76 3.23 2.34 NS NS 5.11 3.71 6.09 4.47 7.6 0.27 0.23 0.29 0.53 0.65 16e LSD (0.05) a k c ^ e rr S Plants grown from single tillers in four-inch pots n = 6 Endophyte-free plants Endophyte-infected plants Estimated values Plants grown from single tillers in six-inch pots No sample 87 Iowa State University Personnel Affiliated with the Turfgrass Research Program Dr. Michael A gn ew Assistant Professor, Extension Turfgrass Specialist. Horticulture Department. Ms. Mary Boyle Undergraduate Research Assistant. Horticulture Department (Christians). Mr. Michael Burt Turfgrass Graduate Student and Research Associate. Horticulture Department M.S. (Christians). Dr. Nick Christians Professor, Turfgrass Science. Research and Teaching. Horticulture Department. Dr. Ken Diesburg Turfgrass Graduate Student and Research Associate. Horticulture Department Ph.D. (Christians). (Graduated December 1987) Dr. Mark G leason Assistant Professor, Extension Plant Pathologist. Plant Pathology Department. Ms. Harlene Hatterman-Valenti Extension Associate. Weed Science Department. Dr. Clinton H od ges Professor, Turfgrass Science. Research and Teaching. Horticulture Department. Dr. Young Joo Turfgrass Graduate Student and Research Associate. Horticulture Department Ph.D. (Christians). (Graduated August 1987 and worked on Postdoctoral Research until February 1988). Dr. Donald Lewis Associate Professor, Extension Entomologist. Entomology Department. Mr. Richard M oore Turfgrass Graduate Student and Research Associate. Horticulture Department M.S. (Christians/Agnew). Mr. Gary Petersen Jasper County Extension Director and Turfgrass Graduate Student.Horticulture Department M.S. (Agnew/Christians). Mr. Zachary Reicher Turfgrass Graduate Student and Research Associate. Horticulture Department M.S. (Christians). (Graduated May 1988). Mr. Grant Spear Turfgrass Graduate Student and Research Associate. Horticulture M.S. + Christians). 88 Companies and Organizations That Made Donations or Supplied Products to the Iowa State University Turfgrass Research Program Special thanks is expressed to the Big Bear Turf Equipment Company and Cushman Turf for providing a Cushman Truckster, a mataway, and a Lawn-Aire IV for use at the research area in 1987; to Tri-State Turf and Irrigation for providing a Greensmaster III Triplex Greensmower for use on the research green; to the Toro Company and Tri-State Turf and Irriga­ tion for providing a Toro 84 Triplex mower; to Professional Turf Specialties Inc. and E-Z-Go Textron for providing two E-Z-Go maintenance trucksters; and to John Deere Company for providing an out-front deck mower. American Hoechst Corporation Agricultural Chemicals Department Route 1 - Box 7 Brownsdale, Minnesota 55918 Chesebrough-Pond’s, Inc. Research Laboratories Trumbull Industrial Park Trumbull, Connecticut 06611 The Andersons Post Office Box 119 Maumee, Ohio 43537 CIBA-Geigy Corporation Agriculture Division Greensboro, North Carolina 27049 Aquatrols Corporation of America 1432 Union Avenue Pennsauken, New Jersey 08110 Classen Manufacturing 1403 Rouch Street Norfolk, Nebraska 68701 Arcadian Corporation 1 Gatehall Drive Post Office Box 265 Parsippany, New Jersey 07054 Cushman Turf 5232 Cushman Lincoln, Nebraska 68501 Cushman-Ryan Inc. Lincoln, Nebraska Big Bear Turf Equipment Company 1840 Fuller Road West Des Moines, Iowa 50265 W. A. Cleary Corporation 1049 Somerset Street Somerset, New Jersey 08873 Britt Tech Corporation Post Office Box 216 Britt, Iowa 50423 D & KTurf Products 8121 Parkview Drive Urbandale, Iowa 50322 89 Dow Chemical 10890 Benson - Suite 160 Shawnee Mission, Kansas 66210 Iowa Golf Course Superintendents Association Iowa Professional Lawn Care Association Dupont Incorporated 1007 Market Street Wilmington, Delaware 19898 Iowa Turf Producers and Contractors Iowa Turfgrass Institute Elanco Products Company 5600 South 42nd Street Post Office Box 3008 Omaha, Nebraska 68103 EniChem Americas, Inc. Research and Development Center 2000 Princeton Corporation Center Monmouth Junction, NJ 08852 E-Z-Go Textron Post Office Box 388 August, Georgia 30906 Fermenta Plant Protection Company Post Office Box 348 7528 Auburn Road Painesville, Ohio 44077 Grain Processing Corporation Muscatine, Iowa 52761 GrassRoots Turf 6143 Southwest 63rd Des Moines, Iowa 50321 Hawkeye Chemical Company Post Office Box 899 Clinton, Iowa 52732 International Seeds 820 First Street Post Office Box 168 Halsey, Oregon 97348 John Deere Company Moline, Illinois 61265 Lebanon Chemical Corporation Country Club Fertilizer Division Post Office Box 180 Lebanon, Pennsylvania 17042 LESCO Incorporated 300 South Abbe Road Elyria, Ohio 44035 Loft-Kellogg Seed 322 East Florida Street Post Office Box 684 Milwaukee, Wisconsin 53201 M & A Enterprises 4346 South 90th Omaha, Nebraska 68127 Monsanto Company Agricultural Products Division 800 North Lindbergh Boulevard St. Louis, Missouri 63167 Nor-Am Chemical Company 3509 Silverside Road Post Office Box 7495 Wilmington, Delaware 19803 Spraying Systems Company N Avenue at Schmale Road Wheaton, Illinois 60187 PBI/Gordon Corporation 1217 West 12th Street Post Office Box 4090 Kansas City, Missouri 64101-9984 Stauffer Chemical Company 10250 Regency Circle Omaha, Nebraska 68114 Pickseed West Incorporated Post Office Box 888 Tangent, Oregon 97389 Professional Turf Specialties Inc. 133 Kenyon Road Champaign, Illinois 61820 Par Ex Swift Agricultural Products Corp. 518 Pauline Drive Buffalo Grove, Illinois 60090 Regal Chemical Company Post Office Box 900 Alpharetta, Georgia 30201 Terra Chemical Corporation Box 218 Quimby, Iowa 51049 The Toro Company Irrigation Division Riverside, California 92500 Rhone-Poulenc Chemical Company Black Horse Lane Post Office Box 125 Monmouth Junction, NJ 08852 Tri State Turf & Irrigation Co. 6125 Valley Drive Bettendorf, Iowa 52722 Ringer Corporation 9959 Valley View Road Minneapolis, Minnesota 55344 Union Carbide Agricultural Products Ambler, Pennsylvania 19002 Riverdale Chemical Company 220 East 17th Street Chicago, Illinois 60411 O. M. Scott and Sons Marysville, Ohio 53040 *ln 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 Nick so your company name can be added in future reports. 91 Cooperative Extension Service, Iowa State University of Science and Technology, and the United S ta tes D epartm ent of,A griculture cooperating. Ronald C. Powers, interim director, Am es, Iowa. D istributed in furtherance o f the A cts o f C o n gress o f M ay 8 and J u n e 30, 19 14 . . . . and justice for all The Iowa C ooperative E xten sion S ervice’s program s and policies are co n sisten t w ith pertin ent federal and state law s and regu lations on n on -discrim ination regarding race, color, national origin, religion, sex, age and han dicap .