OVERSEEDING TRIALS ON FAIRWAY AND PUTTING GREEN BERMUDAGRASSES

Transcription

1 Nutter, G. C. and R. J. Allen, Jr Floratine St. Augustinegrass: A new variety for ornamental turf. Fla. Agr. Exp. Stn. Circ S-123. Reeves, S. A., Jr. and G. G. McBee Nutritional influences on cold hardiness of St. Augustinegrass (Stenotaphrum secundatum). Agron. J. 64: Reinert, J. A., B. D. Bruton, and R. W. Toler Resistance of St. Augustinegrass to southern chinch bug and St. Augustine Decline Strain of Panicum Mosaic Virus. J. Econ. Entomol. 73: Reinert, J. A., P. Busey, and F. G. Bilz Old World St. Augustinegrasses resistant to the southern chinch bug (Heteroptera: Lygaeidae). J. Econ. Entomol. 79: Reinert, J. A. and A. E. Dudeck Southern chinch bug resistance in St. Augustinegrass. J. Econ. Entomol. 67: Riordan, T. P., V. D. Meier, J. A. Long, and J. T. Gruis Registra tion of Seville St. Augustinegrass. Crop Sci. 20: Sauer, J. D Revision of Stenotaphrum (Gramineae: Paniceae) with attention to its historical geography. Brittonia 24: White, R. W. and P. Busey History of turf grass production in Florida. Proc. Fla. State Hort. Soc. : Wilson, C. A., J. A. Reinert, and A. E. Dudeck Winter survival of St. Augustine grasses in North Mississippi. S. Nurserymen's Assoc. Res. Conf. Ann. Rep. 22: Proc. Fla. State Hort. Soc. 105: OVERSEEDING TRIALS ON FAIRWAY AND PUTTING GREEN BERMUDAGRASSES A. E. Dudeck and S. F. Anderson University of Florida, IF AS Environmental Horticulture Department Gainesville, FL Additional index words. Agrostis palustris, creeping bentgrass, Lolium perenne, perennial ryegrass, Poa trivialis, rough bluegrass, turf, turfgrass. Abstract. Differences between 35 cool-season turf grasses overseeded on Tifway II' and Tifdwarf bermudagrasses, Cynodon spp., were noted under fairway and putting green condi tions, respectively, throughout the winter growing season at Gainesville, FL Overseeded putting green grasses with bestt seasonal turf quality were the perennial ryegrass cultivars, '', '', '', and ''; and the rough bluegrass cultivars, '' and ''. Best overseeded fairway grasses were the perennial ryegrass cultivars, '', '', and ''. Throughout the southern United States, fairways and putting greens are overseeded annually with cool-season turf grasses during winter months. This practice is to pro vide green color and improved playing surfaces when bermudagrass undergoes dormancy (Turgeon, 1991). Many cool-season turfgrass species and cultivars along with numerous mixtures and blends are available on the seed market. This is because turfgrass breeders and seed pro ducers continue to develop and release new grasses, mix tures, and blends. Thus, timely trials for proper evaluation are required (Dudeck and Anderson, 1991; Dudeck and McCarty, 1989; Dudeck and McCarty, 1988; Peacocks a/., 1985). The purpose of these studies was to evaluate the suitability of selected cool-season turfgrass species, cul tivars, mixtures, or blends for overseeding purposes in north Florida. Materials and Methods Two concurrent studies were conducted during the winter period, one under fairway conditions and the other under putting green conditions. Thirty-five entries of cool-season grasses listed in Table 1 were overseeded on a 'Tifdwarf bermudagrass, Cynodon spp., put ting green on Oct The same grasses were 2 Florida Agricultural Experiment Station Journal Series No. N overseeded on a 'Tifway IF bermudagrass fairway on - 31 Oct Both studies were conducted at the IFAS Field Laboratory, Gainesville, FL. The putting green site was verticut in several directions and then topdressed at the rate of ft3 per 1,000 ft2 (approximately one-eight inch of soil) one day before overseeding. A fumigated Arredondo fine sand (loamy, silicious, hyperthermic Grossarenic Paleudult) identical to the underlying soil was used for topdressing. Seedbed prepa ration on the fairway site involved only scalping to in ches prior to overseeding. A shaker bottle was used to hand seed all plots accu rately and uniformly through a seeder box, 4 by 6 feet in size. Small seeded grasses such as bentgrass were diluted with a handfull of soil before hand seeding. Seeding rate was based on 50 pure live seed (PLS) inch"2 on the putting green and 15 PLS inch"2 on the fairway (Table 2). After seeding, both sites were topdressed at the previous rate to cover the seed. Preventative fungicides and insecticides were applied throughout the study to minimize disease and insect problems, respectively. Light irrigation was applied twice a day for the first two weeks after seeding. Irrigation was then reduced to a frequency of once per day to meet daily evapotranspiration loss. The putting green and fairway were mowed 3 times per week throughout the growing season. Mowing height on the fairway was 0.75 inches while the putting green was mowed at a height of 0. inches. Clippings were removed only from the putting green. Both sites were fertilized biweekly with a fertilizer with sulfur coated urea N at the rate of pounds N per 1,000 ft2. A total of 6 pounds of N per 1,000 ft2 was applied from Nov to May Data were gathered on rate of establishment based on visual estimates of percent overseeded cover every 3 to 4 days during the first 3 weeks after seeding. Data on per cent cover and weeds were first transformed using angular or square root transformations (Little and Hills, 1978) be fore statistical analyses. Final data were re transformed and presented in tabular form as respective treatment means. Rate of ground cover was calculated after Maguire (1962) as the sum of average daily ground cover estimated for the first 19 days after seeding on the fairway and 21 days after seeding on the putting green. Cover50 values which indi cate days to 50% overseeded ground cover were calculated with a 95% probability. From through May, turf qual ity estimates were recorded biweekly, but they were sum marized and presented in tabular form as average monthly Proc. Fla. State Hort. Soc. 105: 1992.

2 Table 1. Cool-season turfgrasses overseeded at Gainesville, FL during the winter growing period along with their composition and seed source. Composition Turf grass Species2 Mix/Blend Culdvar Seed Source Citation II Sunrye 246 Charger Saturn Citation II Sunrye 246 Quickstart Sunrye 246 Quickstart Pennington Seed CB Emerald Cobra CBL 10 E.F. Burlingham Saturn Envy Zajac Performance Seed Omega 40 Dandy Northurp King Target Laser Northrup King Pennington Seed E.F. Burlingham CB Unknown CB Tee-2-Green 50 Gator Derby Supreme Regal Normarc Seed Normarc Seed Pennington Seed ZCB = deeprng bentgrass, = Perennial ryegrass, = Rough bluegrass. Proc. Fla. State Hort. Soc. 105:

3 Table 2. Cool-season turfgrass seed quality, bulk and pure live seed (PLS) number per pound, and seeding rate for overseeding trials at Gainesville, FL. Seed Seeding Rate Putting Purity Germ Bulk PLS Green Fairway 0 #/lb lbs/0 ft2 Milligan Sunrise , , ,724 2,727 6,670, ,921 2,085, , , , , , , , , , ,3 244,706 6,270,717 6,270, , , ,171 1,850, , ,452 8, ,339 6,243, ,986 1,941, ,888 7, ,788 2, , , , , , , ,124 5,735,323 5,735, , , ,662 1,658, zsee first page narrative for proper seeding rates. Bold represents estimates based on average purity, germination, and seed number of all respective bentgrass and perennial ryegrass entries. Table 3. Average, minimum, maximum air temperatures ( F) and depar ture from normal air temperatures during the growing season at Gainesville, FL.+ Oct. Nov. Jan. Feb. Mar. Apr Max Min Mean Year Average Max Min Mean Departure from 29 Year Average Max trecorded on Agronomy Farm, University of Florida campus. Min Mean estimates. A rating scale of 1 to 9 was used where 1 = poor and 9 = best turf quality. The same scale was used to score grass color and dollarspot disease incidence, Sclerotina homoeocarpa F. T. Bennett, with a rating of 9 being best color or no disease. Annual bluegrass, Poa annua L., was a serious weed problem in the fairway test and was nega tively correlated (r = , p = ) with turf quality. Therefore, turf quality scores on the fairway were adjusted to weed estimates by covariance analyses. 232 Both studies were arranged as randomized complete block designs each with 4 replications. All data were sub jected to analysis of variance. Means were separated with the Waller-Duncan procedure at the 5% level of probabil ity. Results and Discussion The winter averaged 1.9 F. below normal for the growing season (Table 3). Nov., Jan., and Apr. were very cold months and averaged F. below normal. Table 4. Analysis of variance for rate of ground cover and seasonal turf quality of overseeded grasses grown on fairway and putting green locations. Source Location (L) Error A Grass (G) LXG Error B dp Cover 33* *** 12ns 10 Mean squares Quality 8.2ns 2.1*** 0.9*** 0.1 zdf = degrees of freedom. ns> *} *** Not signiflcant or significant at the 0.05 or probability levels, respectively. Proc. Fla. State Hort. Soc. 105: 1992.

4 Table 5. Days to 50% ground cover, rate of ground cover, and average weekly ground cover estimates of cool-season grasses during the first three weeks after overseeding a Tifdwarf bermudagrass putting green 29- Oct at Gainesville, FL. Prelude 15 Cover50z 10.6 ± ± ± ± ± ± ± ± ± ± ± ± ± ] ± L ± S U 12.0 ±c< > ± L.O 1 ± L.9 1 ± L ± 12.9 ± ± ± ± 13.2 ± ± ± ± ± ± ± ± ± ± 0.7 Cover Ratey 2 a* 2 a 20.0 ab 19.8 a-c 19.3 a-d 19.3 a-d 1-d 18.4 a-e 17.9 a-e 17.9 a-e 17.7 a-e 17.7 a-e 1 a-e 1 a-e 1 a-f 1 a-f 1 a-f 1 a-f 1 a-g 1 a-g 1 b-g 1 c-g 1 d-g 1 d-g 1 d-g 14.6 e-g 14.5 e-g 13.1 f-h 12.3 g-i 9.7 h-j 8.3 ij j 0.9 k k 0.0 k 7 44 a 40a-b 33 a-d 41 ab 36 a-d 36 a-d 34 a-d 27 a-e 33 a-d 28 a-e 32 a-d 31 a-d 28 a-e 34 a-d 24b-e 31 a-e 26b-e 28 a-e 27 a-e b-e 23b-e 19c-f 22c-f 19d-f 14 e-g 7fg 2g 2g 0g Oy 0g % Day a-d 70 ab 77 a 66 a-d 69 a-d 69 a-c 68 a-d 70 a-c 62 a-d 64 a-d 62 a-d 56b-f 65 a-d 66 a-d 65 a-d 60b-e 63 a-d 58b-f 60 a-e 55b-f 54b-f 52c-f 53b-f 55b-f 51d-f 54b-f 51d-f 41 fg 42 e-g 31 gh 23 h 17h ab 97 ab 99 a 97 ab 93 a-d 90b-d 95 ab 85 de 87 cd 79 e 70 f 18g 6h Oh zcover50 = days to 50% overseeded cover. ycover Rate = Sum of average daily percent ground cover estimates for the first 21 days after overseeding. xmeans within columns with the same letter are not significantly different (p = 0.05) using Waller-Duncan k-ratio *-test. Light frosts which did not damage any overseeded grass numbered 4 in Nov., 3 in Dec, 10 in Jan, and 2 in Feb. Both bermudagrasses retained their green color, although with limited growth, throughout the growing season. There was no interaction between planting sites and grasses regarding rate of ground cover production (Table 4). However, turf quality on the green and fairway in teracted significantly with overseeded grasses. Con sequently, data on turf performance throughout these studies were presented within planting sites. Putting green study. Rate of overseeded ground cover on the putting green differed among grasses (Table 5). Twenty of the 35 grasses or 57%o of all grasses studied had equally fast ground cover rates which averaged 18.2%. Grasses in this group were '', 'Blend #T, CBS IF, '', '', '', 'Leader Board', '', 'Palmer IF, '', ', '', '', 'Prelude', '', 'Repel IF, '', '', '', and '15' perennial ryegrasses. This group of grasses produced 50% overseeded cover in 11.5±2.1 days. Those overseeded grasses having the slowest ground cover rate which aver aged 0.6% included '', '', and '' bentgrasses. '' and '' bentgrass produced no visible cover in the first 21 days after seeding. Turf quality on the putting green differed between grasses throughout the growing season (Table 6). Only 6 of the 35 grasses or 17% of all grasses tested had equally high sea sonal turf quality scores which averaged 8. This group included 'Blend 1', '', '', and '' pe rennial ryegrasses and '' and '' rough bluegrass. '' and '' perennial ryegrasses had the lowest coefficients of variation (CV's) of 14.6 and %, respectively, indicating that their turf quality was consis tently uniform throughout the entire growing season. Both grasses had equal dark green color ratings of and no dollarspot disease during May. Although '' and '' rough bluegrass had equal seasonal turf quality rat ings of, the '' cultivar had better color and less dollarspot disease in May. The creeping bentgrasses, espe cially '', produced inferior overseeded turf corn- Table 6. ly and seasonal mean values for turf quality, color, and disease on cool-season grasses overseeded on a Tifdwarf bermudagrass putting green from December 1991 to May 1992 at Gainesville, FL. Seasonal Jan. Feb. Mar. Apr. May Mean CVZ Colory Disease" Mixture # 1 Medalist ^ Ratingsw av 8 ab 3 a-c 2 a-d 5 a-e 2 a-f 1 b-g 1 b-g 0 b-g 9 b-g 4 b-g 3 b-g 9 c-g 4 c-g 3 c-g 1 c-g 1 c-g 2 c-g 1 c-g 7 c-g 6 d-g g-1 ab a-d 8.2 a c-i b-e b-e a-c b-f d-1 b-h a-d c-j b-e b-g e-1 a-e b-e e-1 b-f f d ab be 8.0 ab Proc. Fla. State Hort. Soc. 105:

5 Table 6. Continued Jan. Feb. Mar. Apr. May Seasonal Mean CVZ Colory Disease" 15 Check MSDU throughout fsetson. ^ V*rmtlOn " * ^^ f 4.3 Ratings e-g 4 e-g 4 e-g 1 e-g 1 e-g 8 e-g 8 fg 6 fg 5 g 3 gh 0 gh 7 hi 8 i 4.58j 2.32 k a-d d-1 a-e h-1 1m b-h c-k b-h d-1 d-1 c-i 5.2 i-1 k-m j-m 3.8 m 1.2 *" SCaS nal mcan expressed in Percent- rteen ratings ^ete averaged ^Color based on visual ratings of 1 to 9 where 9 = dark green. Three ratings were averaged during Apr Disease based on visual ratings of Dollar Spot where 9 = no disease on 1 May. wquality based on visual ratings of 1 to 9 where 9 = best!^s^^z!ss^5 ^ not significantly different (p = 005) using Waller Duncan k-rado <-test-not TO BE MSD = Minimum significant difference (p = 0.05) using Waller Duncan k-ratio /-test. Table 7. Days to 50% ground cover, rate of ground cover, and average weekly ground cover estimates of cool-season grasses during the first three weeks after overseeding a 'Tifway II' bermudaerass fairwav - 31 Oct at Gainesville, FL Prelude Cover50z 11.0 ± ± ± ± ± ± ± 13.6 ± ± ± ±4.4 ±3.2 1 ± ± ±3.0 ± 1.6 ±4.7 ± 1 ± ± 1 ± 15.7 ±9.6 1 ±4.4 1 ±3.4 1 ± ± 18.3: ± : ± : ± : ± : ± 40.2: ± 1.2 Cover Ratey 13.5 ax 1 ab 1 ab 1 ab 1 ab 11.6a-c 11.6a-c 11.4a-c 11.3a-c 10.9 a-d 10.9 a-d 10.7 a-d 1 a-d 1 a-d 10.2 a-e 10.0 a-f 9.8 a-g 9.6 a-g 9.3 a-h 9.3 a-h 9.0 b-i 7.9 c-j 7-7 c-j d-j e-j f-j g-j h-k i-k 4.4J k-m 0.11m 0.0 m 0.0 m 0.0 m % Day ab 29 ab 26a-c 29 ab 24a-c 29 a 21 a-d 29 ab 21 a-d 18 a-e 24a-c 19 a-e a-c 16 a-e 20 a-e a-c 18 a-e 16 a-f 19 a-e 20 a-e 16 a-f 14 a-f lob-f 7c-f 7c-f 7c-f 5d-f 5d-f 4f 2f 52 a 47 ab 47 ab 45a-c 44a-c 45a-c 35 a-f 41 a-d 39 a-e 37 a-e 37 a-e 32b-g 37 a-e 38 a-e 28c-g b-g 34b-f 22 e-g b-g 24d-g 17 gh 22 e-g 19f-h 22 e-g 20f-g 19f-h 5 hi 76 ab 71 ab 69a-c 67a-c 81a 66a-c 75 ab 71 ab 74 ab 78 ab 62a-c 74 ab 62a-c 71 ab 69a-c 62a-c 56 a-e 60a-c 69a-c 66a-c 58 a-d 68a-c 63a-c 53 a-e 56 a-e 40c-e 53 a-e 29 de 51b-d 27 e 2f If zcover50 = days to 50% overseeded cover. ycover rate = sum of average daily percent ground cover estimates for the first 19 days after overseeding. xmeans within columns with the same letter are not significantly different (p = 0.05) using Wa/ler-Duncan k-ratio /-test a 1.5 pared to all other overseeded grasses tested under putting green conditions. Fairway study. Rate of overseeded ground cover under fairway conditions differed among grasses (Table 7). Twenty of the 35 grasses or 57% of all grasses studied had equally fast ground cover rates which averaged 11.0%. Grasses in this group included '', 'Blend 1\ 'CBS IF, '', 'Cowboy IF, '', '', '', '', '', '', 'Pat riot II', '', '', '', '', 'Repel IF, '', '', and '' perennial ryegrasses. This group of grasses produced 50% overseeded cover in 13.7 ± 3.3 days. Those overseeded grasses having the slowest ground cover rates which aver aged 1.8% were '' and '' rough bluegrass and ''. This group of grasses required an average of 3 ± days to produce 50% overseeded ground cover. Bentgrass cultivars of '', '', and '' produced no visible cover in the first 19 days after seeding in the fairway test. Rates of cover on the fairway were slower than that on the putting green (Tables 5 and 7). This was due to the higher mowing height on the fairway and lower seeding rates which resulted in greater bermudagrass competition with overseeded grasses. Turf quality on the fairway differed between grasses throughout the growing season (Table 8). Only 3 of 35 grasses or 9% of all grasses tested had equally high seasonal turf quality scores which averaged 3. This group in cluded 'Blend 1', 'Palmer IF, and 'Repell IF perennial ryegrass cultivars. As a group, they had low CV's, best dark green color score averaging 8.4, and the least annual bluegrass of 6% indicating they were quite competitive to annual bluegrass. The non-overseeded check plots aver aged 59% annual bluegrass. '' and 'Peimcross' bentgrass had an average seasonal turf quality score of 2.95 which was poorer than all other overseeded grasses. Although '' creeping bentgrass had a better aver- Proc. Fla. State Hort. Soc. 105: 1992.

6 Table 8. ly and seasonal mean values for turf quality, color, and weeds on cool-season grasses overseeded on a Tifway II' bermudagrass fairway from December 1991 to May 1992 at Gainesville, FL. Seasonal Jan. Feb. Mar. Apr. May Mean cvz Color? Weeds" Ratings % 15 Mixture # 1 Check MSDU av 4 ab 4 a-c 5 b-d 4 cd 8 c-e 7 c-e 6 c-f 6 c-f 4 d-g 3 d-g 2 d-g 5 d-h 3 d-i 2 d-i 0 d-i 8 d-i 8 d-i 5 e-j 1 e-j 8 f-j 8 f-j 6 g-j 1 h-j 0 h-j 9 h-j 6ij 6 ij 8j 5.75 k 8 kl m 3.02 n 2.88 n 2.03 o ab 8.5 a-c 8.0 a-e 8.8 a d-g 8.1 a-d f-h d-g gh d-g e-h gh gh gh c-g gh d-g b-g c-g 3.3j b-g gh e-h d-g 7.9 a-f d-g d-h e-h gh d-g h 3.9 ij 4.4 i 4.1 ij 3.5 ij 2.0 k e-h 9 e-h 11 d-h 3gh 4 f-h 13 d-h 12 d-h 2h 6 f-h 8 e-h 11 d-h 10 d-h 10 d-h 2h 18c-h 11 d-h 8 e-h 21 c-f 6 f-h 10 d-h 20 c-g 28 b-d 42 ab 24b-e 42 ab 34 be 59 a 16 ZCV = Coefficient of variation is a measure of relative variation around the seasonal mean expressed in percent. Thirteen ratings were averaged throughout the season. ycolor based on visual ratings of 1 to 9 where 9 = dark green. Three ratings were averaged during Apr. xweeds based on percent cover of annual bluegrass per plot. Three ratings were averaged during Jan. and Feb. wquality based on visual rating of 1 to 9 where 9 = best. vadjusted seasonal means and means within columns followed by the same letter are not significantly different (p = 0.05) using Waller Duncan k-ratio *-test. NOT TO BE INTERETED AS RANKED ORDER OF MEANS. UMSD = Minimum significant difference (p = 0.05) using Waller Duncan k-ratio t-test. age quality score of 3.79, the seeding rate of 15 PLS inch-2 for overseeding bentgrass into fairways is too low (Ward et ai, 1974). Literature Cited 1. Dudeck, A. E. and S. F. Anderson Winter overseeding trials on fairway and putting green bermudagrasses. Proc. Fla. State Hort. Soc. 104: Dudeck, A. E. and L. B. McCarty Comparison of overseeded grasses for putting greens. Proc. Fla. State Hort. Soc. 102: Dudeck, A. E. and L. B. McCarty Comparison of bentgrasses for overseeding. Proc. 36th FTGA Conf. 36: Little, T. M. and F. J. Hills Agricultural experimentation de sign and analysis. John Wiley and Sons, New York, New York. Maguire, J. D Speed of germination - aid in selection and evaluation for seedling emergence and vigor. Crop Sci. 2: Peacock, C. H., A. E. Dudeck, and U. K. Yadav Comparison of cool-season turfgrasses for overseeding putting greens. Proc. Fla. State Hort. Soc. 98: Turgeon, A. J management. Prentice Hall, Englewood Cliffs, NJ. pp Ward, C. Y., E. L. McWhirter, and W. R. Thompson, Jr Evalu ation of cool-season turf species and planting techniques for overseeding bermudagrass golf greens, p In E. C. Roberts (ed.) Proc. 2nd Int. Res. Conf., Blacksburg, VA June ASA and CSSA. Madison, WI. Proc. Fla. State Hort. Soc. 105: