UF IFAS COOPERATIVE FUNGICIDE EFFICACY PROGRAM Report 2007 Philip F. Harmon, UF IFAS Plant Pathology Distributed: North Central Florida Field Day May 21 and 22, 2008 Updates and future reports available on http://turf.ufl.edu Data are not for publication and may not be used without consent of the author. Disclaimer: The use of trade names in this publication is solely for the purpose of providing specific information. UF/IFAS does not guarantee or warranty the products named, and references to them in this publication does not signify our approval to the exclusion of other products of suitable composition. Use pesticides safely. Read and follow directions on the manufacturer's label. Many treatments described below are off-label and were evaluated for research purposes only. Questions or comments can be sent to: Phil Harmon, 1453 Fifield Hall, Gainesville, FL 32611. pfharmon@ufl.edu 352 392 3631 X 340 1
Table of Contents 2007 Page Evaluation of fungicides for control of dollar spot on seashore paspalum Aloha, 2007... 3 Evaluation of fungicides for control of fairy ring on Tifdwarf bermudagrass, 2007... 4 Evaluation of fungicides for turf safety of Hammock centipedegrass, 2007... 6 Evaluation of fungicides for turf safety of Floratam St. Augustinegrass, 2007... 7 Evaluation of fungicides for turf safety of Pristine zoysiagrass, 2007... 8 Evaluation of fungicides for turf safety of Seadwarf seashore paspalum, 2007... 9 Evaluation of fungicides for turf safety of Tifdwarf bermudagrass, 2007... 12 Evaluation of fungicides for control of large patch on Floratam St. Augustinegrass, 2007... 14 Evaluation of fungicides for disease control and turf safety of Mini Verde bermudagrass, 2007... 15 Evaluation of fungicides for large patch and dollar spot control on Aloha seashore paspalum, 2007... 17 Evaluation of fungicides for control of take all root rot on Floratam St. Augustinegrass, 2007... 19 Evaluation of fungicides for control of large patch on Pristine zoysiagrass. 2007... 22 2
SEASHORE PASPALUM (Paspalum vaginatum Aloha ) Dollar spot; Sclerotinia homoeocarpa P.F. Harmon and P. Hill Evaluation of fungicides for control of dollar spot on Aloha seashore paspalum, 2007. Fungicide trials were conducted on an Aloha seashore paspalum plot located at the Plant Science Research & Education Center, University of Florida, Citra, FL. Treatments were applied as listed in table, with a CO 2 backpack boom sprayer calibrated to deliver products in 2 gallons of water per 1000 sq ft (M) through two Teejet flat fan nozzles. Plots were divided into 4 blocks and trt. numbers assigned in a randomized complete block design, subplots being 1m x 2m. Plots were maintained as a fairway; mowed 3 times weekly at 0.5 in. Irrigation was applied at 0.65 in., 3 days a week. Allectus was applied in May. Fungicide applications were applied at the intervals described in the table below; 14 day interval sprays on 17Apr, 1May, 16May, 30May, and 13Jun. The 28 day interval sprays were applied 17Apr, 16May, and 13Jun. Dollar spot readings were taken 17Apr, 10May and 16May. No dollar spot was observed 30May or 11Jun. Turfgrass quality observations (scale of 1-10 with 10=dark green turf, 1=dead/brown turf, and 6=minimally acceptable turf) also were made. All untransformed data were subjected to statistical analysis, and significant differences among means were identified by Waller-Duncan k-ratio t-test. Dollar spot pressure was light throughout the trial. Applications were made curatively, recovery occurred in all plots after the initial application of fungicide. Environmental conditions favored turf growth and recover over disease and were dry and warm. All fungicide treatments reduced the average number of dollar spot infection centers per plot after the first application. The average number of infection centers increased slightly for untreated control plots over this same time period. Many products were DMI fungicides, so plots were monitored carefully for phytotoxicity throughout the trial. No phytotoxicity was observed in any plot. Turfgrass quality was significantly better for most fungicide treatments 2 weeks after the initial applications. Control plots eventually recovered and turfgrass quality across control plots caught up with treatments plots by 30May. These results suggest DMI products including Trinity, Lynx and Banner and the new premix 26/36 product are effective and safe dollar spot materials for seashore paspalum in Florida. Dollar spot Turfgrass quality Product Rate 17-Apr 10-May 16-May 1-May 16-May 30-May 11-Jun 1 Not treated 2.00 2.50 0.25 5.75 6.25 6.25 6.50 2 Trinity 0.5 fl oz 14 d 0.75 0.00 0.00 7.00 7.00 6.50 7.25 3 Trinity 1.0 oz 28 d 1.50 1.00 0.00 6.75 6.75 6.50 7.50 4 Trinity 2.0 fl oz 28 d 3.50 0.25 0.00 7.00 6.75 7.00 7.25 5 UF CEP 1 0.88 oz 14 d 4.25 0.50 0.00 6.50 6.75 6.50 7.50 6 UF CEP 1 1.1 oz 28 d 2.75 0.75 0.00 6.25 7.25 7.00 7.75 7 Cleary's 26/36 8 oz 14 d 2.25 0.50 0.00 6.75 6.50 6.25 6.75 8 Tartan SC 2.0 fl oz 14 d 2.75 0.50 0.00 6.25 7.00 7.00 7.75 9 Lynx 2.0 fl oz 14 d 2.50 1.00 0.00 5.75 6.50 6.25 7.00 10 Banner Maxx 2.0 fl oz 14 d 2.50 0.75 0.50 6.00 6.25 6.50 7.25 z lsd z ns 2.34 ns 1.17 ns ns 0.99 Least significant difference for means within columns according to Waller-Duncan k-ratio t-test (k=100) 3
BERMUDAGRASS (Cynodon dactylon Tifdwarf ) Fairy ring P.F. Harmon, C.M. Stiles and P. Hill Evaluation of fungicides for control of fairy ring on Tifdwarf bermudagrass, 2007. Fungicide trials were conducted on a Tifdwarf Bermudagrass green located at the Plant Science Research & Education Center, University of Florida, Citra, FL. Treatments were applied as listed in the tables, with a CO 2 backpack boom sprayer calibrated to deliver products in 2 gallons of water per 1000 sq ft (M) through two Teejet flat fan nozzles. Treatments 2 through 5 and 15 were applied with Cascade as a tank mix at a rate of 8 oz./m, and plots were watered-in for 15 min after application (0.25 in. water). Cascade was applied and watered-in for 15 min before the fungicide products were applied in treatments 6 through 9. Treatments 10 through 14 were applied without wetting agent but were watered-in for 15 min after application. Plots were divided into 3 blocks and treatment numbers assigned in a randomized complete block design, and subplots were 0.5 m by 1 m. Plots were maintained as a green and were mowed 3 times weekly at 0.165 in. Irrigation was applied at 1.04 in, 7 days a week. The plot was fertilized with 0.5 lbs. N every 2 weeks. Primo Maxx was applied every 2 weeks at a rate of 3oz/A. Orthene also was applied once a month from June October. Fungicide applications were applied at the intervals described in the table below on 1 Jun, 14 Jun, and 28 Jun. Damage severity ratings were made using the Horsfall Barrett (HB) scale (0 = 0 to 1, 1 = 1 to 3, 2 = 3 to 6, 3 = 6 to 12, 4 = 12 to 25, 5 = 25 to 50, 6 = 50 to 75, 7 = 75 to 88, 8 = 88 to 94, 9 = 94 to 97, 10 = 97 to 100%). Damage due to phytotoxicity and fairy ring could not be differentiated. Turfgrass quality observations (scale of 1-10 with 10=dark green turf, 1=dead/brown turf, and 6=minimally acceptable turf) also were made. All untransformed data were subjected to statistical analysis, and significant differences among means were identified by Waller-Duncan k-ratio t-test. Prostar, Insignia, and Heritage TL provided the best control of fairy ring. Insignia applied in a tank mix with Cascade, at 2 gal per M delivery volume, and irrigated in with 0.25 in. of water was numerically better than Insignia applied after a watered-in Cascade only pretreatment (but not significantly different). Endorse treated plots had significantly less damage than untreated plots on the last three rating dates and performed about as well as Headway. Plots treated with Trinity fungicide showed significant phytotoxicity at both the 1.0 and 2.0 fl oz rates. Phytotoxicity damage was difficult to discern from fairy ring damage. However, plots treated with Trinity and Insignia had numerically less damage than plots treated with Trinity alone at the same rate. Trinity applications that were watered-in resulted in less damage than applications made after irrigation. Sterol inhibiting fungicides (SI, DMI) used to treat fairy ring pose significant risk of phytotoxicity on Bermudagrass in Florida. Damage rating Product, surfactant z, rate, and interval 1-Jun 7-Jun 14-Jun 21-Jun 29-Jun 05-Jul 12-Jul 19-Jul 1 Not treated 6.3 6.3 5.7 7.3 7.7 8.3 8.3 9.0 2 Insignia T 0.9 oz 14 d 5.7 4.7 4.7 3.3 2.7 3.7 2.0 4.3 3 Trinity T 1.0 fl oz 14 d 6.3 7.3 7.7 8.0 8.7 10.0 10.7 10.7 4 Trinity T 2.0 fl oz 14 d 6.0 6.3 9.0 8.0 8.3 10.0 10.3 11.0 5 Insignia +Trinity T 0.5 oz + 1.0fl oz 14 d 6.7 6.3 6.3 6.0 6.7 7.7 9.3 8.3 6 Insignia P 0.9 oz 14 d 7.0 6.0 5.0 4.0 3.7 5.0 3.3 5.7 7 Trinity P 1.0 fl oz 14 d 6.0 5.3 5.7 6.3 7.7 7.7 9.7 9.3 8 Trinity P 2.0 fl oz 14 d 6.0 5.7 6.0 6.7 8.0 8.7 10.3 10.0 9 Insignia +Trinity P 0.5 oz + 1.0 fl oz 14 d 5.3 5.7 5.0 6.0 8.0 7.7 9.7 9.7 10 Heritage TL 1.0 fl oz 14 d 5.7 5.0 4.7 4.3 3.7 3.7 3.7 4.7 11 Heritage TL 2.0 fl oz 28 d 6.3 6.0 5.0 5.3 3.7 2.7 2.7 3.3 12 Headway 1.5 fl oz 14 d 5.7 6.0 5.0 6.0 3.3 4.7 4.3 7.0 13 Headway 3.0 fl oz 28 d 6.0 5.0 4.3 4.3 4.3 5.0 6.0 6.3 14 Endorse 4.0 oz 14 d 6.7 7.0 7.0 6.7 5.0 4.3 5.3 6.0 15 Prostar WDG T 2.2 oz 14 d 5.7 5.3 4.7 2.7 2.7 3.3 2.7 3.7 lsd y ns ns 3.4 4.1 2.9 2.7 2.7 3.5 z Cascade added in tank with the fungicide (T), applied as a pretreatment (P), or not used (blank). y Least significant difference between means within columns according to Waller-Duncan k-ratio t-test (k=100). 4
Turfgrass quality Product, surfactant z, rate, and interval 1-Jun 7-Jun 14-Jun 21-Jun 29-Jun 05-Jul 12-Jul 19-Jul 1 Not treated 1.0 1.7 3.7 2.0 2.7 1.0 1.0 1.0 2 Insignia T 0.9 oz 14 d 2.0 3.3 3.7 6.3 6.7 7.0 7.0 5.7 3 Trinity T 1.0 fl oz 14 d 1.0 1.3 1.7 2.0 1.7 1.7 1.3 1.0 4 Trinity T 2.0 fl oz 14 d 1.3 1.3 2.3 2.3 1.7 2.3 1.0 1.0 5 Insignia +Trinity T 0.5 oz + 1.0fl oz 14 d 2.0 2.0 2.7 3.7 4.0 2.3 2.3 2.7 6 Insignia P 0.9 oz 14 d 1.3 1.7 3.0 5.7 5.0 4.0 4.7 3.3 7 Trinity P 1.0 fl oz 14 d 2.0 1.7 2.0 3.0 3.0 2.7 1.7 2.0 8 Trinity P 2.0 fl oz 14 d 2.0 2.3 2.3 3.0 2.7 1.7 1.3 1.0 9 Insignia +Trinity P 0.5 oz + 1.0 fl oz 14 d 2.0 1.7 2.7 3.0 3.7 2.0 1.7 1.3 10 Heritage TL 1.0 fl oz 14 d 1.7 3.3 4.7 6.3 5.3 5.7 5.0 4.3 11 Heritage TL 2.0 fl oz 28 d 2.0 2.0 2.3 5.7 4.7 6.3 6.0 6.3 12 Headway 1.5 fl oz 14 d 2.0 1.7 4.3 6.3 4.0 4.7 4.0 4.7 13 Headway 3.0 fl oz 28 d 1.7 2.7 4.0 6.0 5.3 5.0 4.3 4.0 14 Endorse 4.0 oz 14 d 2.3 1.7 2.7 5.3 4.7 6.0 3.3 3.3 15 Prostar WDG T 2.2 oz 14 d 2.7 3.3 5.0 7.3 6.7 7.7 7.3 6.0 lsd y ns ns ns 2.9 2.9 2.3 3.4 2.7 z Cascade added in tank with the fungicide (T), applied as a pretreatment (P), or not used (blank). y Least significant difference between means within columns according to Waller-Duncan k-ratio t-test (k=100). 5-Jul 2007 Puffball basidiocarps (mushrooms) of fairy ring on a Tifdwarf putting green. Two fungicidetreated plots were digitally outlined in the image. The left has very little fairy ring but shows phytotoxicity associated with DMI fungicides on bermudagrass. The plot on the right has no fairy ring and does not show phytotoxicity. 5
CENTIPEDEGRASS (Eremochloa ophiuroides Hammock ) Turf safety P.F. Harmon and P. Hill Evaluation of fungicides for turf safety of Hammock centipedegrass, 2007. Fungicide trials were conducted on a Hammock Centipedegrass plot located at the Plant Science Research & Education Center, University of Florida, Citra, FL. Treatments were applied as listed in the table, with a CO 2 backpack boom sprayer calibrated to deliver products in 2 gal of water per 1000 sq ft (M) through two Teejet flat fan nozzles. Plots were divided into 3 blocks, and treatments were assigned in a randomized complete block design, subplots were 1m x 2m. Plots were mowed once weekly at 3.0 in. Irrigation was applied at 0.75 in, 3 days a week. The plot was fertilized with 0.75 lbs. N on 10 Jul. Fungicide applications were applied at 14 day interval; on 22 Aug, 7 Sep, 19 Sep, 3 Oct, 17 Oct, and 31 Oct. Turfgrass quality observations (scale of 1-10 with 10=dark green turf, 1=dead/brown turf, and 6=minimally acceptable turf) were made. All untransformed data were subjected to statistical analysis, and significant differences among means were identified by Waller-Duncan k-ratio t-test. No phytotoxicity was observed. These data suggest the DMI fungicides Tourney and Trinity are safe for use on centipedegrass at the rates evaluated. Turfgrass quality Product Rate 22-Aug 5-Sep 14-Sep 26-Sep 10-Oct 31-Oct 15 Nov 1 Not treated 6.7 6.7 6.3 7.3 6.3 6.7 6.7 2 Tourney 0.37 fl oz 7.0 6.7 6.0 6.7 5.7 6.0 6.3 3 Trinity 1.0 fl oz 6.0 6.7 6.0 7.0 5.3 6.0 6.7 lsd z ns ns ns ns ns ns ns z Least significant difference between means within column according to the Waller-Duncan k-ratio t-test (k=100) 6
ST. AUGUSTINEGRASS (Stenotaphrum secondatums Floratam ) Turf safety P.F. Harmon and P. Hill Evaluation of fungicides for turf safety of Floratam St. Augustinegrass, 2007. Fungicide trials were conducted on a Floratam St. Augustinegrass plot located at the Plant Science Research & Education Center, University of Florida, Citra, FL. Treatments were applied as listed in the table, with a CO 2 backpack boom sprayer calibrated to deliver products in 2 gal of water per 1000 sq ft (M) through two Teejet flat fan nozzles. Plots were divided into 3 blocks, and treatments were assigned in a randomized complete block design, subplots were 1m x 2m. Plots were mowed once weekly at 3.0 in. Irrigation was applied as needed. Fungicide applications were applied at 14 day interval; on 22 Aug, 7 Sep, 19 Sep, 3 Oct, 17 Oct, and 31 Oct. Turfgrass quality observations (scale of 1-10 with 10=dark green turf, 1=dead/brown turf, and 6=minimally acceptable turf) were made. All untransformed data were subjected to statistical analysis, and significant differences among means were identified by Waller-Duncan k-ratio t-test. Very slight discoloration of treated plots was noted on 15 and 30 Nov. These data suggest the DMI fungicides Tourney and Trinity are safe for use on St. Augustinegrass at the rates evaluated. Turfgrass quality Product Rate 22-Aug 5-Sep 14-Sep 26-Sep 17-Oct 31-Oct 15 Nov 30-Nov 1 Not treated 5.7 5.7 5.0 5.7 5.7 5.0 6.7 6.0 2 Tourney 0.37 fl oz 6.3 6.0 5.7 6.7 5.3 5.3 6.3 6.0 3 Trinity 1.0 fl oz 5.7 5.7 5.3 6.0 6.3 5.3 6.3 5.7 lsd z ns ns ns ns ns ns ns ns z Least significant difference between means within column according to the Waller-Duncan k-ratio t-test (k=100) 7
ZOYSIAGRASS (Zoysia ophiuroides Pristine ) Turf safety P.F. Harmon and P. Hill Evaluation of fungicides for turf safety of Pristine zoysiagrass, 2007. Fungicide trials were conducted on a Pristine Zoysiagrass tee located at the Plant Science Research & Education Center, University of Florida, Citra, FL. Treatments were applied as listed in the table, with a CO 2 backpack boom sprayer calibrated to deliver products in 2 gal of water per 1000 sq ft (M) through two Teejet flat fan nozzles. Plots were divided into 3 blocks, and treatments were assigned in a randomized complete block design. Subplots were 1m x 2m. Plots were mowed 3 times weekly at 0.5 in. Irrigation was applied as needed. Fungicide applications were applied at 14 day interval; on 22 Aug, 7 Sep, 19 Sep, 3 Oct, 17 Oct, and 31 Oct. Turfgrass quality observations (scale of 1-10 with 10=dark green turf, 1=dead/brown turf, and 6=minimally acceptable turf) were made. All untransformed data were subjected to statistical analysis, and significant differences among means were identified by Waller-Duncan k-ratio t-test. No Phytotoxicity was observed on any date. These data suggest the DMI fungicides Tourney and Trinity are safe for use on Pristine zoysiagrass at the rates evaluated. Turfgrass quality Product Rate 22-Aug 5-Sep 14-Sep 26-Sep 10-Oct 31-Oct 15 Nov 30-Nov 1 Not treated 7.0 5.3 6.3 5.0 5.0 5.7 7.0 6.0 2 Tourney 0.37 fl oz 7.0 6.0 6.0 6.0 5.0 6.3 7.0 6.0 3 Trinity 1.0 fl oz 6.7 5.7 6.0 5.7 5.3 6.3 7.3 6.7 lsd z ns ns ns 0.77 ns ns ns ns z Least significant difference between means within column according to the Waller-Duncan k-ratio t-test (k=100) 8
SEASHORE PASPALUM (Paspalum vaginatum Sea Dwarf ) Turf safety P.F. Harmon and P. Hill Evaluation of fungicides for turf safety of Seadwarf seashore paspalum, 2007. Fungicide trials were conducted on a Seadwarf seashore paspalum research green located at the Plant Science Research & Education Center, University of Florida, Citra, FL. Treatments were applied as listed in table, with a CO 2 backpack boom sprayer calibrated to deliver products in 2 gallons of water per 1000 sq ft (M) through two Teejet flat fan nozzles. Plots were divided into 4 blocks and trt. numbers assigned in a randomized complete block design, subplots being 1m x 2m. Plots were maintained as a green; mowed 3 times weekly at 0.125 in. Irrigation was applied at 0.69 in, 4 days weekly. Fertilizer was applied at a rate of 0.25 N every 2 weeks. Primo Maxx was applied every 2 weeks at 6 oz/a. Orthene was applied once a month, June October. Fungicide applications were applied at 14 day interval; on 13Jun, 26Jun, 10Jul, 24Jul, 8Aug, 22Aug, and 7Sep. Turfgrass quality observations (scale of 1-10 with 10=dark green turf, 1=dead/brown turf, and 6=minimally acceptable turf) also were made. Disease incidence ratings for 19Jul are Fusarium blight infection centers per plot. Incidence data on 8Aug and 26Sep are Horsfall Barrett scale ratings (1 = 0 to 1, 2 = 1 to 3, 3 = 3 to 6, 4 = 6 to 12, 5 = 12 to 25, 6 = 25 to 50, 7 = 50 to 75, 8 = 75 to 88, 9 = 88 to 94, 10 = 94 to 97, 11 = 97 to 100%) All untransformed data were subjected to statistical analysis, and significant differences among means were identified by Waller-Duncan k-ratio t- test. Fusarium blight was observed and rated on plots 19Jul. Disease distribution was not uniform and variation between reps was high. Statistically significant differences were not found at the 95% confidence level, but numerically the two program treatments had the least amount of disease. Trinity, Bayleton, Eagle, and the two higher rates of Instrata had numerically fewer infection centers than the untreated control. It is unknown why Banner, Tartan, Tourney, and the low rate of Instrata had little or no effect on the disease incidence. Brown patch was observed in several subplots on 8Aug. Warm temperature brown patch has been observed to occur on seashore paspalum (in addition to the cool temp large patch). All of the fungicides evaluated prevented brown patch. The 0.5 oz rate of trinity did not completely prevent the disease. Leaf and sheath spot was observed on 26Sep. The disease appeared to move in from one edge of the green and across the trial. The spatial distribution of the disease and limited incidence meant that no statistical differences could be detected. No phytotoxicity was observed on any date reported. Seadwarf paspalum is much more tolerant of DMI fungicide applications than most bermudagrass cultivars. DMI products appear to be a viable fungicide option for seashore paspalum at this time. Turfgrass quality Disease incidence Product Rate 13-Jun 26-Jun 5-Jul 19-Jul 8-Aug 22-Aug 14-Sep 26-Sep 19-Jul 8-Aug 26-Sep Not treated 7.75 8.00 7.50 7.50 5.50 6.25 6.25 5.75 4.00 3.25 1.75 Instrata SE 2.75 oz 7.75 7.75 8.00 7.50 6.50 6.00 5.50 6.00 4.25 0.00 1.25 Instrata SE 4.0 oz 7.75 8.00 8.00 7.75 6.75 5.50 6.00 6.75 2.00 0.00 1.25 Instrata SE 5.5 oz 8.00 8.25 8.25 8.25 6.75 5.50 6.25 5.75 2.25 0.00 1.25 Tartan SC 1.0 oz 7.75 8.50 8.75 7.00 7.00 6.50 6.25 6.50 5.25 0.00 1.25 Headway EC 1.5 oz 8.00 8.25 8.50 7.50 6.75 6.50 6.50 6.50 3.75 0.00 1.25 Tourney 50 WG 0.18 oz 8.00 8.00 8.25 7.00 6.75 6.25 6.75 6.25 4.00 0.00 1.00 Tourney 50 WG 0.37 oz 7.75 7.75 7.75 7.25 6.50 5.50 6.25 6.50 4.50 0.00 1.25 Banner Maxx 1.0 oz 8.00 8.00 8.00 7.25 6.50 6.25 5.25 5.75 6.75 0.00 1.50 Lynx Flo 1.0 oz 8.00 7.75 8.75 8.00 7.00 6.00 6.00 6.00 3.00 0.00 1.50 Trinity 0.5 oz 7.75 7.75 8.00 8.00 6.50 6.00 6.00 6.00 2.75 1.25 1.75 Eagle 1.2 oz 8.00 7.75 8.00 7.50 6.25 6.00 5.75 6.25 2.50 0.00 1.25 Bayleton SC 1.0 oz 7.75 8.00 8.25 7.75 6.75 6.50 7.00 6.25 2.75 0.00 1.00 Syngenta Prog. 1 below 8.00 7.75 8.25 8.25 7.75 6.25 6.25 6.25 1.75 0.00 1.25 Syngenta Prog. 2 below 7.75 7.75 8.00 8.50 7.00 6.25 6.75 6.75 1.00 0.00 1.00 lsd z ns ns ns ns 1.54 ns 1.40 ns ns 1.05 ns z Least significant difference between means within columns according to Waller-Duncan k-ratio t-test (k=100) 9
Rate Syng. Prog. 1 Headway MEC 1.5 oz Medallion + Signature 0.5 + 4.0 oz Concert SC 4.2 oz Heritage TL + Medallion 1.0 + 0.25 oz Headway MEC 1.5 oz Syng. Prog. 2 Banner Maxx + Medallion 1.0 + 0.5 oz Daconil Ultrex + Signature 3.2 + 4.0 oz Heritage TL 1.0 oz Daconil Ultrex + Medallion 3.2 oz + 0.5 oz Headway MEC 1.5 oz 24 Aug-Fusarium blight on seashore paspalum intermediate rough adjacent to trial 10
8 Aug-Brown patch caused by Rhizoctonia solani on seashore paspalum in area adjacent to trial 26 Sep-Leaf and sheath spot caused by R. zeae in area adjacent to trial. 11
BERMUDAGRASS (Cynodon dactylon Tifdwarf ) Turf safety P.F. Harmon and P. Hill Evaluation of fungicides for turf safety of Tifdwarf bermudagrass, 2007. Fungicide trials were conducted on a Tifdwarf Bermudagrass plot located at the Plant Science Research & Education Unit, University of Florida, Citra, FL. Fungicides were applied with a CO 2 backpack boom sprayer calibrated to deliver products in 2 gallons of water per 1000 sq ft (M) through two 8003 Teejet flat fan nozzles. Plots were divided into 4 blocks and treatments were assigned in a randomized complete block design. Plots were 1m x 2m and were mowed 3 times weekly at 0.150 in. Irrigation was applied as needed. Fungicide applications were applied on 23 May and 6 Jun. Turfgrass quality observations (scale of 1-10 with 10=dark green perfect turf, 1=dead/brown turf, and 6=minimally acceptable turf) were made. All untransformed data were subjected to statistical analysis, and significant differences among means were identified by Waller-Duncan k-ratio t-test. Least significant difference between treatment means for each date is given in the table (k=100) No disease was observed prior to the initial application of fungicide treatments, and no additional fungicides were applied to control disease. Severe phytotoxicity was observed 14 Jun on some plots. No further treatment was applied after 6 Jun. Overall turfgrass quality in the plot was poor, even for non-treated control plots. The research plot was significantly stressed, and turfgrass qualities reflect that the green would not have been acceptable for most golfers. Turfgrass quality aspects affected most in treated plots included turf density and color. Plots treated with Tourney and with the highest rates of Trinity (1 and 2 oz) were significantly thinner, yellow in color, and slightly stunted and wilted in appearance. Leaf blades were bronzed in some treatments and growth of the bermudagrass nearly stopped leading to weed pressure and exposed sand in the worst plots (ratings in the 1 and 2 range). The north side of the plot was more stressed than the east side, which is probably why the standard deviations of the means were higher than most trials. Conclusions from this research: 1 application of the products evaluated did not significantly reduce turfgrass quality at the rates tested. After the second application, phytotoxicity and a decrease in turfgrass quality was noted in most treatment plots to some degree. The 14 Jun rating is the most significant indication of treatment effects. Effects were not as noticeable in later dates, as is indicated by the higher LSD values. The phytotoxic effects were not apparent at the 22 Aug rating except in the Tourney, although turfgrass quality was still low for the green. DMI fungicides should be used with caution on bermudagrass greens in FL. If used, preventative rates limited to one application should continue to be and are recommended for any DMI product. Turfgrass quality Product Rate 23-May 1-Jun 6-Jun 14-Jun 27-Jun 5-Jul 19-Jul 8-Aug 22-Aug 1 Not treated 4.50 3.75 4.25 5.00 4.50 4.75 4.00 5.75 4.00 2 Trinity 0.5 fl oz 4.75 4.25 4.25 4.50 3.75 4.25 3.75 5.00 3.75 3 Trinity 0.75 fl oz 5.00 3.75 4.00 4.00 3.00 3.00 2.75 4.50 3.50 4 Trinity 1.0 fl oz 4.50 3.75 4.25 3.75 3.00 3.25 3.00 5.00 3.25 5 Trinity 2.0 fl oz 4.75 3.50 4.00 1.50 1.75 2.50 2.25 4.50 3.00 6 Banner Maxx 1.0 fl oz 5.00 4.50 4.50 4.25 4.75 4.25 4.00 5.50 3.50 7 Bayleton WG 1.0 oz 5.00 4.00 4.75 2.50 4.50 4.25 3.25 5.25 3.75 8 Eagle WSP 1.2 oz 5.00 4.50 4.75 4.50 4.25 4.00 3.75 5.75 3.50 9 Lynx 1.0 fl oz 5.25 4.50 4.50 2.75 2.75 3.00 3.25 5.00 3.25 10 Tourney 0.37 oz 4.50 3.75 3.50 1.25 1.50 1.75 1.50 3.00 2.50 z lsd z ns ns ns 1.25 1.54 1.70 2.27 2.65 ns Least significant difference according to Waller-Duncan k-ratio t-test (k=100) 12
14 June 2007 Overview image of trial showing significant phytotoxicity in some treated plots (yellow and thin rectangles) 8 days after second application. 13
ST. AUGUSTINEGRASS (Stenotaphrum secondatums Floratam ) Large patch; Rhizoctonia solani P.F. Harmon and P. Hill Evaluation of fungicides for control of large patch on Floratam St. Augustinegrass, 2007. Fungicide trials were conducted on a Floratam St. Augustinegrass plot located at the Plant Science Research & Education Center, University of Florida, Citra, FL. Treatments were applied as listed in table, with a CO 2 backpack boom sprayer calibrated to deliver products in 2 gallons of water per 1000 sq ft (M) through two Teejet flat fan nozzles. Plots were divided into 4 blocks and trt. numbers assigned in a randomized complete block design, subplots being 1m x 2m. Plots were mowed once weekly at 4.0 in. Irrigation was applied at 0.72 in, 4 days a week. Fungicide applications were applied at 28 day interval; on 4Apr and 2May. Turfgrass quality observations (scale of 1-10 with 10=dark green turf, 1=dead/brown turf, and 6=minimally acceptable turf) also were made. All untransformed data were subjected to statistical analysis, and significant differences among means were identified by Waller-Duncan k-ratio t-test. No disease was observed in this trial. Environmental conditions were too dry and warm for large patch development in spring 2007. Treatments were repeated in a fall trial in the same location. z Turfgrass quality Product Rate 4-Apr 17-Apr 1-May 16-May 1-Jun 11-Jun 27-Jun 5-Jul 1 Not treated 6.00 5.50 6.00 4.75 6.25 6.25 6.50 6.25 2 Armada WP 1.2 oz 6.00 5.25 5.75 4.75 6.00 5.75 6.00 5.75 3 Armada WP 1.5 oz 6.00 5.50 6.00 4.75 5.75 6.00 6.25 6.25 4 Prostar WP 2.2 oz 6.00 5.25 6.00 5.00 6.25 6.25 6.75 6.75 5 Prostar 70 WG 2.2 oz 6.00 5.50 5.75 5.25 6.00 5.75 5.75 6.25 6 Heritage TL 2 oz 5.75 5.50 5.75 5.50 5.75 5.75 6.00 6.50 7 Insignia 0.9 oz 6.25 6.00 5.75 5.75 6.00 6.25 6.50 6.50 lsd z ns ns ns ns ns ns ns ns Least significant difference between means according to Waller-Duncan k-ratio t-test (k=100) 14
BERMUDAGRASS (Cynodon dactylon Mini Verde ) Turf safety P.F. Harmon and P. Hill Evaluation of fungicides for disease control and turf safety of Mini Verde bermudagrass, 2007. Fungicide trials were conducted on a Mini Verde Bermudagrass plot located at the Plant Science Research & Education Center, University of Florida, Citra, FL. Treatments were applied as listed in table, with a CO 2 backpack boom sprayer calibrated to deliver products in 2 gallons of water per 1000 sq ft (M) through two Teejet flat fan nozzles. Plots were divided into 4 blocks and trt. numbers assigned in a randomized complete block design, subplots being 1m x 2m. Plots were mowed 3 times weekly at 0.125 in. Irrigation was applied at 1.0 in 4 days weekly. Primo Maxx was applied every 2 weeks at a rate of 6oz/A. Orthene was applied once a month, June October. Fungicide applications were applied at 21 days interval described in the table below on 22 May, 21 Jun, 5Jul, 7Aug, 28Aug, 18 Sep, and 16Oct. Turfgrass quality observations (scale of 1-10 with 10=dark green turf, 1=dead/brown turf, and 6=minimally acceptable turf) were made. NDVI (normalized difference vegetation index) were taken with a Crop Circle hand-held sensor (Holland Scientific). All untransformed data were subjected to statistical analysis, and significant differences among means were identified by Waller- Duncan k-ratio t-test. The green was established 2006 and was still in the grow-in phase in spring. A dry spring and summer 2007 reduced disease pressure, and the grass grew vigorously most of the trial. Fairy ring symptoms were noted outside the plot area in Aug. The low overall turf quality rating on 14Sep was due to cultivation and topdressing. Fungicide-treated plots seemed to recover more quickly from the cultivation than untreated plots. Significant differences in turfgrass quality were observed in the fall and throughout winter after the end of the trial. Differences were still apparent through the beginning of March 2008. The treated plots had numerically higher turfgrass quality ratings on nearly every date. Results from this trial suggest that even if a summer fungicide program increases turfgrass quality only marginally during summer months, treated plots may continue to benefit into more stressful conditions of fall and winter long after treatments cease. Turf quality Program 23-May 6-Jun 11-Jun 5-Jul 19-Jul 8-Aug 22-Aug 5-Sep 14-Sep 26-Sep 1 Not treated 5.75 6.25 5.25 7.00 6.25 6.75 6.00 6.00 4.75 5.75 2 Bayer prog 1 6.00 6.50 5.50 6.75 7.25 7.25 6.50 6.25 5.00 6.25 3 Bayer prog 2 6.00 6.50 5.75 6.75 7.00 6.75 6.50 6.50 5.50 6.75 4 Syngenta prog 1 6.00 5.75 5.50 7.50 7.25 6.75 6.50 5.75 5.25 6.00 5 BASF prog 1 5.75 6.25 5.75 7.00 7.00 6.50 6.25 6.50 5.00 6.75 6 BASF prog 2 5.75 6.50 6.25 7.25 7.50 7.25 6.50 6.50 5.25 6.00 z lsd z ns ns ns ns ns ns ns ns ns 0.87 Turf quality NDVI 2008 17-Oct 15-Nov 6-Dec 03-Mar 1 Not treated 5.25 6.00 5.50 0.5619 2 Bayer prog 1 5.50 7.00 6.25 0.6006 3 Bayer prog 2 5.75 8.00 7.00 0.6020 4 Syngenta prog 1 5.50 6.75 6.25 0.6148 5 BASF prog 1 6.00 7.00 6.50 0.6074 6 BASF prog 2 5.25 7.00 6.50 0.5954 lsd z ns 0.28 1.38 0.0289 Least significant difference between means within columns according to Waller-Duncan k-ratio t-test (k=100) 15
1 Not treated 5 BASF 1 2 Bayer Prog. 1 App. 1 Curalan 1 oz App. 1 Signature + Chipco 26 GT 4 oz + 4 oz. App. 2 Daconil Ultrex 3.2 oz App. 2 Signature + Cleary's 3336 4 oz + 4 oz. App. 3 Insignia 0.9 oz App. 3 Signature + Compass 4 oz + 0.25 oz. App. 4 Clearys 3336+ 2 oz App. 4 Signature + Prostar WDG 4 oz + 2.2 oz. App. 5 Insignia + Fore 0.9 + 8 oz App. 5 Signature + Chipco 26 GT 4 oz + 4 oz. App. 6 Daconil Ultrex 3.2 oz App. 6 Signature + Prostar WDG 4 oz + 2.2 oz. App. 7 Curalan 1 oz App. 7 Signature + Compass 4 oz + 0.25 oz. App. 8 Daconil Ultrex 3.2 oz App. 8 Signature + Daconil Ultrex 4 oz + 3.2 oz. App. 9 Insignia 0.9 oz App. 9 Signature + Chipco 26 GT 4 oz + 4 oz. App. 10 Clearys 3336+ 2 oz App. 10 Signature + Tartan SC 4 oz + 1.5 oz. App. 11 Insignia + Fore 0.9 + 8 oz App. 11 Signature + Lynx 4 oz + 1 oz. 6 BASF 2 3 Bayer Prog. 2 App. 1 Insignia+ Fore 0.9 + 8 oz App. 1 Signature + Fore 4 oz + 4 oz. App. 2 Insignia+ Fore 0.9 + 8 oz App. 2 Signature + Cleary's 3336 4 oz + 4 oz. App. 3 Insignia+ Fore 0.9 + 8 oz App. 3 Signature + Chipco 26 GT 4 oz + 4 oz. App. 4 Daconil Ultrex 3.2 oz App. 4 Signature + Prostar WDG 4 oz + 2.2 oz. App. 5 Iprodione Pro 3 oz App. 5 Signature + Daconil Ultrex 4 oz + 3.2 oz. App. 6 Clearys 3336+ 2 oz App. 6 Signature + Heritage WG 4 oz + 0.4 oz. App. 7 Insignia+ Fore 0.9 + 8 oz App. 7 Signature + Chipco 26 GT 4 oz + 4 oz. App. 8 Insignia+ Fore 0.9 + 8 oz App. 8 Signature + Cleary's 3336 4 oz + 4 oz. App. 9 Daconil Ultrex 3.2 oz App. 9 Signature + Chipco 26 GT 4 oz + 4 oz. App. 10 Iprodione Pro 3 oz App. 10 Signature + Tartan SC 4 oz + 1.5 oz. App. 11 Clearys 3336+ 2 oz App. 11 Signature + Lynx 4 oz + 1 oz. 4 Syngenta 1 App. 1 Daconil Ultrex + Medallion 3.2 + 0.25 oz App. 2 Daconil Ultrex + Signature 3.2 + 4 oz App. 3 Heritage TL 2 oz App. 4 Daconil ZN+ Subdue 6 + 0.5 oz App. 5 Cleary's 3336+ 2 oz App. 6 Daconil Ultrex + Signature 3.2 + 4 oz App. 7 Daconil ZN+ Medallion 6 + 0.25 oz App. 8 Daconil Ultrex + Medallion 3.2 + 0.25 oz App. 9 Daconil Ultrex + Signature 3.2 + 4 oz App. 10 Heritage TL 2 oz App. 11 Daconil ZN+ Subdue 6 + 0.5 oz 16
SEASHORE PASPALUM (Paspalum vaginatum Aloha ) Large patch; Rhizoctonia solani, dollar spot; Sclerotinia homoeocarpa P.F. Harmon and P. Hill Evaluation of fungicides for control of large patch and dollar spot on Aloha seashore paspalum, 2007. Fungicide trials were conducted on an Aloha seashore paspalum plot located at the Plant Science Research & Education Center, University of Florida, Citra, FL. Treatments were applied as listed in table, with a CO 2 bicycle wheel sprayer calibrated to deliver products in 2 gallons of water per 1000 sq ft (M) through four Teejet flat fan nozzles. Plots were divided into 4 blocks and treatments were assigned in a randomized complete block design. Subplots were 2m by 2m. Plots were maintained as a tee; mowed 2 times weekly at 0.5 in. Irrigation was applied at 0.69 in., 3 days a week. Conserve was sprayed on 20 Sep. Fertilizer was applied at 0.75 lbs. N on 10 Jul and 1.0 lbs N on 27 Sep. On 17 Oct, the plot was inoculated with Rhizoctonia solani (isolate 05-08B)-infested wheat seed, approximately 1200 ml, scattered over the whole plot. Fungicide applications were made at the intervals described in the table below; 14 day interval sprays; treatments 2 through 6, on 10 Oct, 24 Oct, 7 Nov, and 26 Nov. The 28 day interval sprays were applied 10 Oct and 7 Nov. The 7 day interval sprays were applied on 10 Oct and 17 Oct. All sprays were applied 23 Jan due to symptoms of large patch and dollar spot. Dollar spot readings were taken 31 Oct, 30 Nov, 9 Jan, 23 Jan, and 7 Feb. A large patch reading was taken 30 Nov and 23 Jan. Turfgrass quality observations (scale of 1-10 with 10=dark green turf, 1=dead/brown turf, and 6=minimally acceptable turf) also were made; 10 Oct, 15 Nov, 30 Nov, 17 Dec, 9 Jan, 23 Jan, and 7 Feb. All untransformed data were subjected to statistical analysis, and significant differences among means were identified by Waller-Duncan k-ratio t-test. The turfgrass quality of the tee was borderline acceptable at the beginning of the trial. By the end of October, greater than 75% of the untreated plots showed some large patch symptom, but symptoms were not severe and were difficult to rate. Once the entire plots had shown some disease symptom, additional decline in affected areas due to disease activity were recorded as decreases in turfgrass quality whenever disease became active. Rhapsody had no measurable efficacy for large patch, but provided some measurable reduction of dollar spot. The level of control provided by Rhapsody would not have been acceptable, but it may have a place as a tank-mix or rotation partner. Endorse provided some large patch control shortly after the two applications that lasted through mid-november but did not provide any dollar spot control in this study. Heritage and Prostar treated plots were among those with the least large patch but had dollar spot counts similar to control plots as expected. Bayleton, Tartan, and the first programmatic application (Syngenta 1) were among the best plots for both dollar spot and large patch control. Syngenta 2 included a first application of Instrata followed by Daconil and Signature. This rotation did not provide the expected large patch control or dollar spot control. No phytotoxicity was observed during the trial. Int z Turfgrass quality Product Rate (wk) 10-Oct 15-Nov 30-Nov 17-Dec 9-Jan 23-Jan 7-Feb 19-Mar Not treated 6.50 5.00 5.50 4.50 6.00 4.00 4.75 4.25 Syngenta 1 * 2 6.25 7.00 6.50 6.75 6.25 5.00 5.25 6.25 Syngenta 2 * 2 6.25 5.75 5.75 5.50 6.25 5.75 4.75 5.25 Rhapsody 5.0 oz 2 6.50 5.25 5.50 5.00 5.50 4.50 5.00 4.50 Armada 1.5 oz 2 6.50 5.75 6.00 5.00 6.25 5.00 5.25 5.75 Heritage TL 2.0 fl oz 2 6.50 6.25 6.25 5.75 6.50 5.50 5.00 5.75 Tartan SC 2.0 oz 4 6.50 6.25 6.25 5.75 6.75 4.75 5.75 5.75 Lynx SC(Flo) 1.5 fl oz 4 6.50 5.25 5.75 5.50 6.25 4.75 5.00 6.25 Prostar 70WG 2.2 oz 4 7.00 6.25 6.00 6.50 7.00 5.50 5.75 6.50 Bayleton SC 2.0 fl oz 4 6.50 6.50 6.25 5.25 6.50 4.75 5.00 6.00 Endorse 4.0 oz 1 6.50 6.00 5.50 5.00 6.00 4.00 4.75 4.75 lsd y ns 0.9 0.9 1.1 1.3 1.4 0.9 1.4 z interval of application in weeks y least significant difference between means within columns according to Waller Duncan k-ratio t-test (k=100) 17
Int z LP incidence LP severity Product Rate (wk) 31-Oct 13-Mar 30-Nov 23-Jan 27-Feb Not treated 7.5 2.25 0 2 3.25 Syngenta 1 * 2 2.5 1 0 2.25 2 Syngenta 2 * 2 6.25 1 0 2 2.25 Rhapsody 5.0 oz 2 7.00 1 0 0 2.75 Armada 1.5 oz 2 6.25 1 0 3 2.5 Heritage TL 2.0 fl oz 2 5.25 1 0.75 0 1 Tartan SC 2.0 oz 4 6.50 1 0 5 1.25 Lynx SC(Flo) 1.5 fl oz 4 7.25 1 0 0 1.25 Prostar 70WG 2.2 oz 4 4.50 1 0 0 1 Bayleton SC 2.0 fl oz 4 4.50 1 0 2.5 3.5 Endorse 4.0 oz 1 5.25 1 1.25 1 4.25 lsd y 1.5 ns ns ns 1.5 z interval of application in weeks y least significant difference between means within columns according to Waller Duncan k-ratio t-test (k=100) Int z Dollar spot incidence Product Rate (wk) 31-Oct 30-Nov 23-Jan 7-Feb 27-Feb Not treated 5.50 0.00 7.00 5.50 12.00 Syngenta 1 * 2 2.00 0.00 0.25 0.75 0.50 Syngenta 2 * 2 5.25 0.00 5.00 0.00 2.75 Rhapsody 5.0 oz 2 4.25 0.00 3.25 1.25 8.75 Armada 1.5 oz 2 4.75 0.00 0.50 0.50 0.50 Heritage TL 2.0 fl oz 2 4.00 0.25 6.75 5.75 17.00 Tartan SC 2.0 oz 4 4.25 0.00 0.25 0.50 0.00 Lynx SC(Flo) 1.5 fl oz 4 5.50 0.00 3.25 0.25 3.25 Prostar 70WG 2.2 oz 4 3.75 1.00 6.25 4.75 17.75 Bayleton SC 2.0 fl oz 4 3.00 0.25 0.50 0.25 0.25 Endorse 4.0 oz 1 4.25 2.00 3.50 2.00 6.00 lsd y 2.0 0.8 4.0 3.0 6.9 z interval of application in weeks y least significant difference between means within columns according to Waller Duncan k-ratio t-test (k=100) * Explanation of Syngenta program treatments Products Rates Date Syng. Prog. 1 Headway + Daconil Ultrex 1.5 + 3.2 oz 10/10 Medallion + Signature 0.5 + 4.0 oz 10/24 Concert SC 4.2 oz 11/7 Instrata 5.0 oz 11/21 Syng. Prog. 2 Instrata 2.75 oz 10/10 Daconil Ultrex + Signature 0.5 + 3.2 oz 10/24 Medallion + Headway 0.5 + 1.5 oz 11/7 Concert 4.2 oz 11/21 18
ST. AUGUSTINE GRASS (Stenotaphrum secondatums Floratam ) Take all root rot; Gaeumannomyces graminis var graminis P.F. Harmon and P. Hill Evaluation of fungicides for control of take all root rot on Floratam St. Augustinegrass, 2007. Fungicide trials were conducted on a Floratam St. Augustinegrass plot located at the Plant Science Research & Education Center, University of Florida, Citra, FL. Sod was laid on 9Jul under a shade structure with 35% shade. Treatments were applied as listed in table, with a CO 2 backpack boom sprayer calibrated to deliver products in 2 gallons of water per 1000 sq ft (M) through two Teejet flat fan nozzles. Plots were divided into 4 blocks and trt numbers assigned in a randomized complete block design, subplots being 1m x 2m. Plots were mowed once weekly at 4.5 in. Irrigation was applied 4 days per week at 0.6 in. Fungicide applications were applied at 28 day intervals; on 13Jul, 10Aug, and 7Sep. Samples were taken from the plot and observed microscopically for signs of the take all root rot pathogen- Gaeumannomyces graminis var graminis. Turfgrass quality observations (scale of 1-10 with 10=dark green turf, 1=dead/brown turf, and 6=minimally acceptable turf) also were made. Take all root rot disease ratings were taken 22Aug using the Horsfall Barrett (HB) scale (0 = 0 to 1, 1 = 1 to 3, 2 = 3 to 6, 3 = 6 to 12, 4 = 12 to 25, 5 = 25 to 50, 6 = 50 to 75, 7 = 75 to 88, 8 = 88 to 94, 9 = 94 to 97, 10 = 97 to 100%). Gray leaf spot was also observed in the plot 19Jul and a HB severity reading was taken. NDVI (normalized difference vegetation index) readings were taken with a Crop Circle hand-held sensor (Holland Scientific). All untransformed data were subjected to statistical analysis, and significant differences among means were identified by Waller-Duncan k-ratio t-test Sod was cut from an area with confirmed infestation of G.g.g. showing early above-ground symptoms, and severe root rotting. Gray leaf spot and take all root rot symptoms were quite severe throughout the trial, but the majority of the sod area survived into fall. Turfgrass quality was low across the trial, but the sod was purposefully stressed after installation. Reductions in turf quality were directly related to take all root rot and gray leaf spot disease severity. The shade structure limited air movement and encouraged gray leaf spot. Prostar treated plots had the most gray leaf spot and the most severe take all root rot symptoms of treated plots. These treatments further confirmed observed disease was not Rhizoctonia-related early in the trial. Armada, Insignia, and Nativo-treated plots had the least take all root rot disease. Lynx + compass and Heritage TL plots had less disease than control plots but numerically more than the other fungicide treated plots. In mid- November large patch caused by Rhizoctonia solani was observed in the plot areas. Prostar treated plots were not affected by large patch and by the end of Novenber had significantly higher turfgrass quality scores than untreated control plots. Large patch pressure was not uniform, and no disease severity rating was taken. Statistically significant differences were limited by substantial between-plot variation. Larger plots and fewer treatments would have helped differentiate. No phytotoxicity was observed throughout the trial. Turfgrass quality Product Rate 19-Jul 10-Aug 22-Aug 7-Sep 14-Sep 26-Sep 1 Not treated 4.75 4.50 4.25 5.00 3.75 5.25 2 Armada WP 1.2 oz 4.00 5.50 4.75 5.00 4.75 6.00 3 Armada WP 1.5 oz 5.00 6.00 5.50 5.25 6.25 6.00 4 Prostar WP 2.2 oz 4.50 4.50 3.75 5.00 3.75 6.25 5 Prostar 70 WG 2.2 oz 4.25 3.75 3.50 5.00 3.75 6.25 6 Heritage TL 2 oz 5.00 5.00 4.75 5.25 5.00 6.25 7 Insignia 0.9 oz 5.50 6.00 5.75 5.25 6.00 5.25 8 Lynx + Compass 0.4 + 0.1 oz 5.25 4.75 4.75 5.50 4.75 5.00 9 Nativo 300 SC 1.0 oz 5.50 6.25 5.50 5.50 5.25 6.00 z lsd z ns 1.16 1.20 ns 1.83 ns Least significant difference between means within columns according to Waller-Duncan k-ratio t-test (k=100) 19
Turfgrass quality NDVI GLS TARR Product Rate 17-Oct 15-Nov 30-Nov 31 Oct 30-Nov 03-Mar 19-Jul 22-Aug 1 Not treated 4.75 5.25 4.75 0.6103 0.5878 0.5577 5.00 8.00 2 Armada WP 1.2 oz 5.00 6.50 6.00 0.6220 0.6315 0.6062 5.25 4.25 3 Armada WP 1.5 oz 5.50 6.50 7.00 0.6333 0.6540 0.5895 4.00 3.50 4 Prostar WP 2.2 oz 5.50 6.50 7.00 0.6706 0.6765 0.6012 5.50 8.25 5 Prostar 70 WG 2.2 oz 6.00 6.50 6.25 0.6862 0.6993 0.6136 6.00 7.75 6 Heritage TL 2 oz 5.00 6.00 6.25 0.6434 0.6429 0.5907 3.25 6.75 7 Insignia 0.9 oz 4.75 5.75 6.00 0.6077 0.6054 0.5986 3.00 3.50 8 Lynx + Compass 0.4 + 0.1 oz 5.00 5.50 5.75 0.5914 0.6097 0.5890 4.75 5.50 9 Nativo 300 SC 1.0 oz 5.25 5.75 5.50 0.6097 0.6031 0.5732 3.00 3.50 lsd z 1.06 ns 1.98 0.0520 0.0490 ns ns 3.22 z Least significant difference between means within columns according to Waller-Duncan k-ratio t-test (k=100) 24 Aug 2007 Foratam St. Augustinegrass sod showing yellowing thinning symptoms of take all root rot. Significant differences between fungicide treated and untreated plots were recorded. 20
30 Nov 2007 Sod showing symptoms of take all root rot and some large patch. Rectangle areas of darker-green and denser turf were treated with fungicides. 21
ZOYSIAGRASS (Zoysia japonica Pristine ) Large patch; Rhizoctonia solani P.F. Harmon and P. Hill Evaluation of fungicides for control of large patch on Zoysia grass Pristine, 2007. Fungicide trials were conducted on a Pristine zoysiagrass plot located at the Plant Science Research & Education Center, University of Florida, Citra, FL. Treatments were applied as listed in table, with a CO 2 backpack boom sprayer calibrated to deliver products in 2 gallons of water per 1000 sq ft (M) through two Teejet flat fan nozzles. Plots were divided into 4 blocks and trt. numbers assigned in a randomized complete block design, subplots being 2m x 1m. Plots were maintained as a tee; mowed 2 times weekly at 0.5 in. Irrigation was applied at 0.69 in., 3 days a week. Conserve was sprayed on 20 Sep. Fertilizer was applied at 0.75 lbs. N on 10 Jul and 1.0 lbs N on 27 Sep. The plot was inoculated with Rhizoctonia solani (isolate 05-08B) infested wheat seed, approximately 1200 ml scattered over the whole plot, 17 Oct. No large patch symptoms were observed by 21 Nov. On 21 Nov, the plot was re-inoculated with Rhizoctonia solani (isolate 04-72) infested wheat seed, by sprinkling approximately 10 ml of infested seed in a 4 circle in the middle of each subplot. Fungicide applications were made at the intervals described in the table below; 14 day interval sprays; treatments #2, 3,4, and 6 on 10 Oct, 24 Oct, 7 Nov, and 26 Nov. The 28 day interval sprays were applied 10 Oct, and 7 Nov. Treatment # 5 was applied only twice, 10 Oct and 24 Oct. Treatment # 11 was applied 10 Oct and 17 Oct. All treatments were applied 17 Jan, due to large patch symptoms observed on 15 Jan. Large patch severity readings were taken 23 Jan and 7 Feb. Turfgrass quality observations (scale of 1-10 with 10=dark green turf, 1=dead/brown turf, and 6=minimally acceptable turf) were made; 10 Oct, 15 Nov, 30 Nov, and 23 Jan. All untransformed data were subjected to statistical analysis, and significant differences among means were identified by Waller-Duncan k-ratio t-test. Large patch was active in the fall and resulted in a decline of turfgrass quality although symptoms were not distinct patches. Disease again became active in early spring on 15 Jan, so one additional application was made. The plots treated with fungicides other than Endorse and Rhapsody had better turf quality and less disease than plots that were not treated. Plots treated with the Syngenta program 2, Prostar, Heritage TL, and Lynx stood out above the rest with excellent turf quality on different dates. At the end of the trial plots treated with Syngenta program 1, Heritage TL, Prostar, Tartan, and Lynx were those with the highest turfgrass quality and least large patch. The premix product 23/36 provided intermediate control. Rhapsody and Endorse did not provide lasting control at the rates and timings tested. No phytotoxicity was observed during the trial. 22
Int z Turfgrass quality Large patch sev Product Rate (wk) 10-Oct 31-Oct 15-Nov 30-Nov 23-Jan 19-Mar 23-Jan 7-Feb Not treated 6.0 6.3 7.0 6.3 5.3 5.8 4.8 5.3 Syngenta 1 * 2 5.8 6.0 6.5 6.8 6.3 7.5 1.3 1.3 Syngenta 2 * 2 6.5 6.5 7.8 8.0 6.0 7.3 2.8 4.3 Rhapsody 5.0 oz 2 5.8 4.8 6.5 6.0 5.0 5.5 5.3 5.3 Cleary's 26/36 4.0 oz 2 6.5 7.0 7.8 7.8 5.8 7.0 3.5 2.3 Heritage TL 2.0 fl oz 2 5.8 6.3 7.0 7.3 6.8 7.5 1.0 1.3 Tartan SC 2.0 oz 4 6.0 6.3 7.8 7.3 6.8 7.0 1.8 1.0 Lynx SC(Flo) 1.5 fl oz 4 6.3 6.3 7.5 7.3 7.5 7.3 1.0 1.0 Prostar 70 WG 2.2 oz 4 6.0 6.5 7.3 7.8 6.8 7.0 1.8 2.8 Bayleton SC 2.0 fl oz 4 6.3 6.3 7.5 7.3 6.3 7.0 2.3 2.0 Endorse 4.0 oz 1 6.0 6.3 7.5 6.8 5.0 5.3 5.3 4.8 lsd y ns ns ns 1.7 1.4 1.6 1.9 1.7 z interval of application in weeks y least significant difference between means within columns according to Waller Duncan k-ratio t-test (k=100) * Explanation of Syngenta program treatments Products Rates Date Syng. Prog. 1 Headway + Daconil Ultrex 1.5 + 3.2 oz 10/10 Medallion + Signature 0.5 + 4.0 oz 10/24 Concert SC 4.2 oz 11/7 Instrata 5.0 oz 11/21 Syng. Prog. 2 Instrata 2.75 oz 10/10 Daconil Ultrex + Signature 0.5 + 3.2 oz 10/24 Medallion + Headway 0.5 + 1.5 oz 11/7 Concert 4.2 oz 11/21 23