Table 11. Brown Patch on Ryegrass Location: Hancock Turfgrass Research Center, E. Lansing, MI Rating Scale: Percent area infected with brown patch.

Transcription

1 Brown Patch (Rhizoctonia solani) A preventive brown patch study was set up on a ryegrass plot area at the Hancock Turfgrass Research Center, E. Lansing, MI. The study was set in a randomized complete block design with 4 replicates of each treatment. Plots measured 2 x 6 with 1 alleys. Treatments were applied using a CO 2 backpack sprayer at 36 PSI and 48 GPA, unless otherwise noted in Table 11, using a single 8002E Tee Jet flat fan nozzle. The ryegrass study area was inoculated on 6/9, 6/29, 7/19, and 8/2 with Rhizoctonia solani growing on a sand/cornmeal mixture using a drop spreader. Plots were fertilized at a rate of 0.8# N/1000 ft 2 /month on both studies. Treatments were applied beginning on June 28 unless otherwise noted in Table 11. Subsequent applications of the 14-day treatments were made on 7/13 and 7/28. The 21-day treatments were reapplied on 7/22, and the 28 day treatments on 7/28. Plots were rated for percent area blighted by brown patch (see Table 11.) Data were analyzed using ANOVA and means separated with LSD (p=0.05). Disease conditions were unfavorable this year for brown patch. We had an average of 15% of the plot area diseased in our control plots at our earliest rating representing the height of our disease pressure (Table 11.) Due to such low disease pressure, all 14 and 28 day interval treatments provided significant control, compared to the untreated control, on the first rating date. Disease pressure subsided after the first rating, and from then on, no significant differences were obtained when treatments were compared to the untreated control. No phytotoxicity was observed in the study. Table 11. Brown Patch on Ryegrass Location: Hancock Turfgrass Research Center, E. Lansing, MI Rating Scale: Percent area infected with brown patch. Treatment and Rate/1000 sq ft EXP lbs EXP lbs Compass 50 WG 0.2 oz Jul 22 Jul 29 5-Aug (Days) Mean a LSD Mean a LSD Mean a LSD 14 (3 apps) 1.8 B 0.8 B 1.8 AB 14 (3 apps) 1.3 B 0.0 B 0.0 B 14 (3 apps) 0.3 B 0.8 B 0.1 B Insignia 0.5 oz B 0.0 B 0.0 B Insignia 0.9 oz B 0.0 B 0.0 B Iprodione Pro 4 fl oz B 2.8 B 0.3 B Echo fl oz B 0.0 B 0.0 B Echo oz B 0.0 B 0.0 B Propiconazole 1.3ME 2 fl oz B 0.0 B 0.1 B 18-Plus Flowable 3 fl oz AB 5.3 B 2.4 AB Heritage 0.2 oz B 0.0 B 0.0 B Chipco 26GT 4 fl oz B 1.3 B 1.4 AB

2 Control 14.8 A 3.8 B 1.4 AB a Means followed by the same letter do not differ significantly (LSD, p=0.05). Summer Patch (Magnaporthe poae) This study was established on an irrigated annual bluegrass fairway at the Dearborn Country Club in Dearborn, MI. The study consisted of 4 replicate 6 x 9 plots in a random block design. Treatments were applied preventively with a CO 2 backpack sprayer at 36 PSI and 2 gallons/1000 sq ft application volume, unless otherwise indicated in Table 12. The treatments that were applied when soil temperature at 2 depth was 55º were initiated on April 20. Those treatments that were applied beginning at 65º at 2 were initiated on May 3, and those at 75º at 2 on June 7. Subsequent reapplications were made according to the intervals listed in Table 12. Fertility was applied as needed with the study receiving approximately ½ lb N/1000 sq ft/month. The study area was background sprayed with Subdue Maxx (1 fl oz) on June 28 and July 13, and with Chipco 26GT (2 fl oz) on June 28, July 13, and August 8 to prevent development of dollar spot, brown patch or Pythium blight in the test area. Data represent percent plot area diseased (Table 12). Quality differences are noted in Table 12. As the data in Table 12 indicate, summer patch disease pressure was very light due to the unusually mild temperatures we experienced this summer. Our control had an average of only 8.5% of the plot area diseased at the height of infection. Most treatments had significantly less disease than the control. Clearys 3336, Heritage/Banner Maxx, Secure (alone and in program treatments), Banner Maxx (alone and in combination treatments), Compass, Insignia, and several new experimental products were among the treatments that provided good summer patch control. No phytotoxicity was observed in this study. Table12. Summer Patch Location: Dearborn Country Club, Dearborn, MI Rating Scale: Percent area infected with summer patch. 2-Aug 16-Aug 24-Aug Treatment and Rate/1000 sq ft (Days) d Mean a Mean a Mean a oz (4 apps) 0.0 i 0.0 i 0.5 h A fl oz i 0.0 i 0.0 h A fl oz 28 (2 apps) 0.0 i 0.0 i 0.0 h Heritage 50WG 0.4 oz + Banner Maxx 2 fl oz 28 (2 apps) 0.0 i 0.0 i 0.0 h A oz 28 (2 apps) 0.0 i 0.0 i 0.5 h Secure 32 ml/100 m2 21(3 apps) 0.1 hi 0.0 i 0.1 gh Secure 64 ml/100 m2 28 (2 apps) 0.1 hi 0.0 i 0.4 h Secure 64 ml/100 m2 75 then 0.0 i 0.0 i 0.4 h Compass 50WDG 7.6g/100 m2 28 then Secure 64 ml/100 m2 28 Banner 3 fl oz + Daconil Ultrex 3.2 oz (3 apps) 0.1 hi 0.1 i 0.5 h 20

3 A oz hi 0.1 I 0.5 h Banner Maxx 2 fl oz hi 0.1 i 0.1 h Banner Maxx 103 ml/100 m2 28 (2 apps) 0.3 hi 0.1 i 0.0 h Banner Maxx 4 fl oz 28 (2 apps) 0.0 i 0.2 i 0.5 h oz (4 apps) 0.3 hi 0.3 i 1.8 f-h Banner Maxx 4 fl oz hi 0.3 i 0.1 h Secure 64 ml/100 m2 21 (2 apps) 0.0 i 0.3 i 0.5 h Compass 0.25 oz + Bayleton 2 oz (3 apps) 0.8 f-i 0.3 i 0.8 gh Compass 0.25 oz + Bayleton 2 oz + Signature 4 oz (3 apps) 0.4 g-i 0.4 i 0.3 h Secure 16 ml/100 m2 21(3 apps) 0.3 hi 0.4 i 0.6 gh Secure 32 ml/100 m2 75 then 0.4 g-i 0.6 hi 0.1 h Compass 50WDG 3.8g/100 m2 21 then Secure 32 ml/100 m2 21 Insignia 0.9 oz (3 apps) 1.5 c-i 0.6 hi 1.1 gh Banner Maxx 4 fl oz 28 (2 apps) 0.8 f-i 0.8 g-i 0.4 h Compass 50WDG 7.6g/100 m2 28 (2 apps) 0.3 hi 1.0 f-i 2.8 d-h Banner Maxx 4 fl oz d-i 1.4 f-i 1.3 gh Insignia 20WG 0.9 oz 28 (2 apps) 1.0 e-i 1.5 f-i 1.8 f-h Heritage TL 0.8ME 2 fl oz 28 (2 apps) 1.0 e-i 1.8 e-i 1.6 f-h Insignia 0.9 oz d-i 1.8 e-i 2.1 f-h Insignia 0.9 oz b 28 (2 apps) 2.0 a-i 1.8 e-i 2.0 f-h Insignia 0.9 oz e-i 2.3 d-i 2.3 f-h Heritage TL 0.8ME 1 fl oz e-i 2.4 d-i 2.5 e-h Insignia 20WG 0.5 oz a-c 2.5 d-i 3.9 c-h Compass 50WDG 7.6g/100 m2 21 (2 apps) 0.9 f-i 2.5 d-i 2.9 d-h Heritage 50WG 0.2 oz a-i 2.8 d-i 1.3 gh Compass 50WDG 3.8g/100 m2 21(3 apps) 3.5 a-g 3.1 d-i 1.8 f-h Heritage 50WG 0.4 oz 28 (2 apps) 3.1 a-i 3.3 c-i 4.3 b-h Insignia 0.9 oz c 28 (2 apps) 2.3 a-i 4.4 b-h 1.8 f-h Insignia 0.9 oz 28 (2 apps) 1.8 b-i 4.5 b-g 2.1 f-h Compass 50WDG 1.9 g/100m2 21(3 apps) 4.1 a-e 5.5 a-e 10.8 a Heritage 0.4 oz (3 apps) 3.6 a-f 6.0 a-d 6.1 a-g Gary's Green 6 fl oz + Ultra Plex 3 fl oz + Griggs Exp #2 6 fl oz 65, d-i 7.0 a-c 9.5 ab Heritage 50WP 6g/100 m2 28 (2 apps) 5.0 a 7.3 ab 8.1 a-d Control 7.0 a-h 8.5 a 8.0 a-e a Means followed by the same letter are not significantly different (LSD, p=0.05). b Treatment applied in 4 gallons/1000 sq ft application volume. c Treatment applied in 1 gallon/1000 sq ft application volume. d Treatments not labeled with 55º, 65º or 75º degree initiation times were initiated at 75º. 21

4 Moss Eradication Moss Study A The study was set up on an annual bluegrass green where a severe moss infestation existed. It was set up in a randomized complete block design with 4 replicate plots per treatment. The plots measured 2 x 4.5 with 1 alleys. Spray treatments were applied using a CO 2 backpack sprayer set at 35 psi with a single 8002E flat fan Tee Jet nozzle. Spray application volume was 3 gal/1000 sq ft. Granular treatments were applied by hand, followed by a light drench with water after each application. Plots were mowed at using a triplex mower. Plots were fertilized with Country Club ( ) as follows: 6/29 (1/2 lb N), 7/13 (1/4 lb N), 7/28 (1/4 lb N), 8/5 (1/4 lb N). Initial treatment application for most treatments occurred on 6/18 unless noted in Table 13 and 14. Plots were rated by visually estimating the percent plot area with moss. An initial rating was taken on June 16 prior to treatment application, and percent turf recovery as of Sept 8 was calculated and is presented in Table 13. Plots were also rated for phytotoxicity to annual bluegrass on a 1-5 scale where 1 indicates no damage to the turf and 5 indicates severe turfgrass phytotoxicity (Table 14). Note that the Lebanon treatments were not started until July 16 (Table 14) so no pretreatment rating was available for their inclusion in Table 13. A percent recovery was calculated for them based on August 6 and Sept 8 ratings and is included as a footnote in Table 13. The experimental product L-0481 provided excellent moss control and was the only treatment to provide statistically significant recovery when compared to the untreated control (Table 13.) It caused mild phytotoxicity (Table 14) with the 5 oz rate causing more than the 2.5 oz rate. Table 13. Moss Location: Hancock Turf Research Center, E. Lansing, MI. Rating Scale: Percent turf recovery from June 16 (initial rating) - Sept 8. Treatment and Rate/1000 sq ft (days) Mean a,b L oz a L oz a Signature 4 oz ab Control b-e TD oz d-f TD oz fg Gary's Green 6 fl oz + Ultra Plex 3 fl oz + Griggs Exp #2 6 fl oz fg TD oz fg a b Treatment means followed by the same letter do not significantly differ (LSD, p=0.05). Note: Lebanon Part B 1/2X rate treatment applied on 7/16, 7/23, 7/29, 8/6, 8/12, 8/30, and 9/10 provided 60.8% recovery from Aug 6 Sept 8 which was not significantly different from the control which had 42.1% recovery. No data are available for the Lebanon Part A + Lebanon Part B 1X rate treatment applied on 7/16, 7/29, and 8/12. 22

5 Table 14. Turfgrass Phytotoxicity Rating. Location: Hancock Turf Research Center, E. Lansing, MI. Rating Scale: 1-5, 1=no damage, 5=severe burn (days)* June 21 Aug 13 Mean a,b Mean a,b Treatment and Rate/1000 sq ft Gary's Green 6 fl oz + Ultra Plex 3 fl oz + Griggs Exp #2 6 fl oz f 1.0 ef Control 1.0 f 1.0 ef TD oz ef 1.3 d-f TD oz d-f 1.3 d-f Signature 4 oz f 1.3 d-f TD oz f 1.5 c-e L oz cd 2.0 d L oz c 2.0 d Lebanon Part A + Lebanon Part B 1X rate 7/16, 7/29, 8/12 na 2.7 b Lebanon Part B 1/2 X rate 7 na 3.3 a a b Treatment means followed by the same letter do not significantly differ (LSD, p=0.05) *7 day treatment applied on: 6/18, 6/25, 7/2, 7/9, 7/16, 7/23, 7/29, 8/6, 8/12, 8/30, 9/10, 9/20, 9/25; 14 day treatments applied on: 6/18, 7/9, 7/23, 8/6, 8/30, 9/10, 9/25; and 21 day treatment applied on: 6/18, 7/2, 7/23, 8/12, 9/10. Moss Study B The study was set up on an annual bluegrass green where a severe moss infestation existed. It was set up in a randomized complete block design with 4 replicate plots per treatment. The plots measured 2 x 4.5 with 1 alleys. Spray treatments were applied using a CO 2 backpack sprayer set at 35 psi with a single 8002E flat fan Tee Jet nozzle. Spray application volume was 3 gal/1000 sq ft. Granular treatments were applied by hand followed by a light drench with water after each application. Plots were mowed at using a walk mower. Plots were fertilized with urea as follows: 6/30 (1/8 lb), 7/13 (1/8 lb), 7/23, (1/8 lb), 7/28 (1/8 lb), 8/5 (1/8 lb). Initial treatment application for most treatments occurred on 6/18 unless noted in Table 15 and 16. Plots were rated by visually estimating the percent plot area with moss. An initial rating was taken on June 16 prior to treatment application, and percent turf recovery as of Sept 8 was calculated and is presented in Table 13. Plots were also rated for phytotoxicity to annual bluegrass on a 1-5 scale where 1 indicates no damage to the turf and 5 indicates severe turfgrass phytotoxicity (Table 14). Note that the Lebanon treatments were not started until July 16 so no pretreatment rating was available for their inclusion in Table 15. A percent recovery was calculated for them based on August 6 and Sept 8 ratings and is included as a footnote in Table 15. The experimental product L-0481 provided excellent moss control and was the only treatment to provide statistically significant recovery when compared to the untreated control (Table 13.) It caused mild to moderate phytotoxicity (Table 14) with the 5 oz rate causing more phytotoxicity than the 2.5 oz rate. 23

6 Table 15. Moss Location: Hancock Turf Research Center, E. Lansing, MI. Rating Scale: Percent recovery from June 16 - Sept 8. (days) Mean a,b L oz a L oz ab Signature 4 oz b-d Control c-e TD oz fg TD oz gh Gary's Green 6 fl oz + Ultra Plex 3 fl oz + Griggs Exp #2 6 fl oz gh TD oz h a b Treatment means followed by the same letter do not significantly differ (LSD, p=0.05) Note: Lebanon Part B 1/2X rate treatment, applied on 7/16, 7/23, 7/29, 8/6, 8/12, 8/30, and 9/10, provided 22.9% recovery from Aug 6 Sept 8. Lebanon Part A + Lebanon Part B 1X rate treatment, applied on 7/16, 7/29, and 8/12, provided 48.2% recovery. Neither were significantly different from the control which had 51.3% recovery over the same time period. Table 16. Turfgrass Phytotoxicity Rating. Location: Hancock Turf Research Center, E. Lansing, MI. Rating Scale: 1-5, 1=no damage, 5=severe burn (days) June 21 Aug 13 Mean a,b Mean a,b Treatment and Rate/1000 sq ft Gary's Green 6 fl oz + Ultra Plex 3 fl oz + Griggs Exp #2 6 fl oz h 1.3 fg Signature 4 oz h 1.3 fg Control 1.0 h 1.3 fg TD oz h 1.5 e-g TD oz gh 1.8 d-f TD oz fg 1.8 d-f L oz gh 2.5 c L oz c-e 3.3 b 7/16, 7/29, 8/12 NA 3.3 b Lebanon Part A + Lebanon Part B 1X rate Lebanon Part B 1/2 X rate 7 NA 4.0 a a b Treatment means followed by the same letter do not significantly differ (LSD, p=0.05). *7 day treatment applied on: 6/18, 6/25, 7/2, 7/9, 7/16, 7/23, 7/29, 8/6, 8/12, 8/30, 9/10, 9/20, 9/25.; 14 day treatments applied on: 6/18, 7/9, 7/23, 8/6, 8/30, 9/10, 9/25; and 21 day treatment applied on: 6/18, 7/2, 7/23, 8/12, 9/10. 24

7 Yellow Tuft This trial was conducted on a Penncross creeping bentgrass green at the Hancock Turfgrass Research Center, E. Lansing, MI. The plot area was mowed at Fertility was maintained as needed. The study was set up in a randomized complete block design with four replications of each treatment. Plots measured 2 x 6. Treatments were applied at 36 PSI in a 1 gal/1000 sq ft spray volume using a CO 2 backpack sprayer and a single 8002E Tee-Jet flat fan nozzle. Initial treatment application was made on July 12. Re-applications of treatments on a 14 day schedule were made on 7/27, 8/9, 8/23, 9/7 and 9/20; 21 day schedule on 8/2, 8/30, and 9/13; and 28 day schedule on 8/9 and 9/7. Percent plot area with yellow tuft was visually estimated, and the means are reported in Table 17. Data were analyzed using ANOVA and means separated by LSD (p= 0.05). Insignia and Subdue Maxx provided statistically significant control of yellow tuft compared to the untreated control plots. As disease continued to increase in the untreated plots, disease remained stable in the Insignia and Subdue Maxx plots. No phytotoxicity was observed. Table 17. Yellow Tuft 2004 Location: Hancock Turf Research Center, E. Lansing, MI. Rating Scale: Percent plot area with yellow tuft. 8-Sep 22-Sep Treatment and Rate/1000 sq ft (Days) Mean a,b Mean a,b Insignia 0.9 oz b 0.9 c Subdue Maxx 1 fl oz b 1.0 c Insignia 0.5 oz b 2.8 bc Heritage 0.4 oz ab 6.3 ab Control a 8.0 a a b Treatment means followed by the same letter do not significantly differ (LSD, p=0.05). Necrotic Ring Spot This trial was conducted on a Kentucky bluegrass stand mowed at 3 at the Hancock Turfgrass Research Center, E. Lansing, MI. The study was set up in a randomized complete block design with four replicates of each treatment. Plots measured 6 x 6. Treatments were applied at 36 PSI in a 2 gal/1000 sq ft spray volume using a CO 2 backpack sprayer and a single 8002E Tee-Jet flat fan nozzle. Fertilizer was applied to all fungicide-treated plots (not Ringer Turf Restore plots, fertilized or unfertilized controls) at ¼ lb N/1000 sq ft on the following dates: 5/19, 6/2, 6/16, 6/30, 7/15, 7/26, 8/12. A ½ lb fertilizer application was made on 9/15. Irrigation was applied on an daily basis. Initial treatment applications were made on May 19 with 25

8 reapplications on June 16, July 14, August 12, September 15, and October 11. Percent plot area with necrotic ring spot was visually estimated, and percent recovery was calculated based on the initial disease rating taken on May 19. The percent recovery means are reported in Table 18. Data were analyzed using ANOVA and means separated by LSD (p= 0.05). Quality ratings were taken and the means are reported in Table 19. Ringer s Turf Restore proved to be the best curative treatment in our study. The Turf Restore treatment received ½ lb N/1000 sq ft/month more fertilizer than the rest of the fertilized treatments. By the last rating date, it was the only treatment to provide 100% recovery. For every rating except the June 18 date, Turf Restore was the only treatment to provide significantly more recovery than the fertilized control treatment. None of the other treatments provided recovery that was significantly better than the fertilized control at any time during the study. Turf quality yielded similar results with the Turf Restore being the only product to provide statistically significant better quality than the fertilized control for the entire duration of the study. No phytotoxicity was observed. Table 18. Necrotic Ring Spot 2004 Location: Hancock Turf Research Center, E. Lansing, MI. Rating Scale: Percent recovery from initial disease rating on May 19. Treatment and Rate/1000 sq ft (Days) Mean a,b Mean a,b Mean a,b Mean a,b Mean a,b Mean a,b Rating Date 18-Jun 8-Jul 5-Aug 20-Aug 10-Sep 6-Oct Ringer Turf Restore 1 lb N/mo ab 57.5 a 75.0 a 80.6 a 94.4 a a Insignia 0.9 oz ab 28.3 bc 28.3 bc 36.7 b 50.0 b b Heritage 0.4 oz a 36.5 ab 39.6 b 42.7 b 52.1 b 47.9 bc Banner Maxx 4 fl oz ab 19.8 b-d 29.0 bc 33.1 bc 44.8 bc 47.7 bc Insignia 0.5 oz ab 31.7 b 40.4 b 38.3 b 42.9 bc 43.3 bc Fertilized control 1/2 lb N/mo ab 16.1 b-d 26.1 bc 26.1 bc 37.5 bc 40.0 bc Emerald 0.18 oz ab 4.3 cd 7.1 cd 10.4 c 19.6 c 22.1 c Unfertilized control b -2.1 d -2.1 d d d d a b Treatment means followed by the same letter do not significantly differ (LSD, p=0.05). 26

9 Table 19. Necrotic Ring Spot Quality Ratings 2004 Location: Hancock Turf Research Center, E. Lansing, MI. Rating Scale: 1-10, where 1=poor, 6=acceptable, and 10=best. Treatment and Rate/1000 sq ft (Days) Mean a,b Mean a,b Mean a,b 8/20 9/10 10/6 Ringer Turf Restore (10-2-6) 1 lb N/mo a 8.3 a 8.0 a Insignia 0.9 oz b 6.8 b 7.0 b Heritage 0.4 oz b 6.5 b 7.0 b Banner Maxx 4 fl oz b 6.5 b 7.3 b Insignia 0.5 oz b 6.3 bc 6.8 b Emerald 0.18 oz b 5.8 cd 5.8 c Fertilized control 1/2 lb N/mo bc 5.5 de 5.8 c Unfertilized control c 5.0 e 5.0 d a b Treatment means followed by the same letter do not significantly differ (LSD, p=0.05). Dollar Spot Timing Study Two dollar spot timing studies were set up with fungicide treatments being made early in the season. They were conducted on an annual bluegrass/perennial ryegrass fairway (0.5 height of cut) and a creeping bentgrass green (0.150 height of cut). Both studies were set in randomized complete block designs and consisted of 4 replicate 2 x 6 plots with 1 alleys. Treatments were applied using a CO 2 backpack sprayer at 36 PSI and 2 gal/1000 sq ft using a single 8002E Tee Jet flat fan nozzle. Plots were fertilized as needed. Treatments were applied on the dates listed in Table 20. Plots were rated for percent area blighted by dollar spot (see Table 20.) Data were analyzed using ANOVA and means separated with LSD (p=0.05). In the fairway study, disease pressure was good. The Emerald treatments applied 5 and 3 times throughout the study had little to no dollar spot though the August 20 rating date. All 3 of the Emerald treatments tested in this study and the Banner Maxx at 1.75 oz applied on May 15 and June 16 provided significant dollar spot control compared to the control though August 20. No phytotoxicity was observed in the study. Unfortunately, little to no disease developed in the study on the creeping bentgrass green so no data are available for that study. 27

10 Table 20. Dollar Spot Timing Study 2004 Location: Hancock Turfgrass Research Center, E. Lansing, MI. Rating Scale: Percent plot area blighted by dollar spot. 8/3 8/12 8/20 Treatment and Rate/1000 sq ft (Days) Mean a,b Mean a,b Mean a,b Emerald 0.18 oz 6/15, 7/16, 7/29, 8/16, 9/ f 0.0 e 0.1 e Emerald 0.18 oz 7/1, 8/2, 9/1 1.1 ef 1.1 e 0.2 e Emerald 0.18 oz May 15, June ef 4.9 de 5.4 de Banner Maxx 1.75 fl oz May 15, June c-f 7.3 c-e 9.3 c-e Banner Maxx 3 fl oz May 15, June ef 8.0 c-e 10.5 b-e Banner Maxx 3 fl oz 15-May 1.3 de 14.3 a- d 11.5 b-e Triticonazole 1 fl oz 15-May 2.1 c-f 11.3 b-e 13.8 a-d Chipco 26GT 4 fl oz 15-May 1.3 d-f 14.3 a-d 14.5 a-d Bayleton 1 oz 15-May 2.5 b-f 17.5 a-d 16.8 a-d Banner Maxx 1.75 fl oz 15-May 3.5 a-f 18.8 a-c 18.8 a-c Control 6.0 ab 26.3 a 21.3 a-b a Mean of 4 replications. b Treatment means followed by the same letter do not significantly differ (LSD, p=0.05). Preventive Dollar Spot (Rutstroemia floccosum) on Creeping Bentgrass This study was set up on a creeping bentgrass/annual bluegrass putting green in four replications of a randomized complete block design. The plots measured 2 x 6 with 6 alleys. Spray treatments were applied using a CO 2 backpack sprayer set at 38 psi with a single 8002E Tee Jet flat fan nozzle. Spray volume was 1 gallon/1000 sq ft. Plots were irrigated as needed and fertility was maintained at approximately 3/8 lb N/1000 sq ft/month with Country Club ( ) fertilizer. Applications dates were: 7/12 (1/4 lb), 7/29 (1/4 lb), 8/13 (1/8 lb), 9/1 (1/8 lb), 9/10 (1/8 lb), and 9/21 (1/8 lb). Initial treatment applications for the program treatments were applied in mid June and reapplied on the dates indicated in Tables 16 and 17. The 14-day treatments were applied on 8/3, 8/18, 9/1, and 9/15. The 21-day treatments were applied on 8/3, 8/27, and 9/15. The 28-day treatments were applied on 8/3 and 9/1. Data represent mean percent plot area infected (Table 21). Quality ratings were also taken using a 0 (worst) to 10 (best) scale where 7 = acceptable turf quality (Table 22.) As the data in Table 21 indicate, dollar spot pressure was modest on the bentgrass study this year. All treatments provided statistically significant control of dollar spot, with all the standard treatments (Rubigan, Echo, Banner Maxx, Daconil Ultrex, Emerald, Chipco 26GT) providing comparable disease control. The Velocity treatments were the poorest performers, possibly due to the moderate phytotoxicity observed in these treatments (Table 22.) 28

11 29

12 Table 21. Preventive Dollar Spot Study on Creeping Bentgrass, Location: Hancock Turfgrass Research Center, E. Lansing, MI. Rating Scale: Mean % plot area blighted by dollar spot. 8-Sep 15-Sep 22-Sep 29-Sep (Days) Mean a,b Mean a,b Mean a,b Mean a,b Treatment and Rate/1000 sq ft Rubigan AS 1.5 oz d 0.0 d 0.0 c 0.0 c V SC 0.44 fl oz d 0.0 d 0.0 c 0.0 c V SC 0.66 fl oz d 0.0 d 0.0 c 0.0 c V WDG oz d 0.0 d 0.0 c 0.0 c Banner Maxx 0.5 fl oz d 0.0 d 0.0 c 0.0 c Insignia 0.9 oz d 0.0 d 0.0 c 0.0 c Daconil Ultrex 3.2 oz d 0.0 d 0.0 c 0.1 c Emerald 0.18 oz d 0.1 d 0.0 c 0.0 c Chipco 26GT 4 fl oz d 0.0 d 0.0 c 0.0 c Emerald 0.18 oz c na 0.1 d 0.1 d 0.0 c 0.2 c Propiconazole Pro 1 oz 15-Jun Curalan 1oz 15-Jul Emerald 0.18 oz 15-Aug Propiconazole 1.3ME 2 fl oz d 0.0 d 0.0 c 0.0 c Banner Maxx 1 fl oz 24-Jun 0.1 d 0.1 d 0.1 c 0.3 c Chipco 26GT 4 fl oz 15-Jul Daconil Ultrex 3.2 oz 29-Jul Daconil Ultrex 3.2 oz 12-Aug Spectro 4 oz cd 0.2 cd 0.2 c 0.3 c Velocity 30 g ai/a cd 0.4 cd 0.4 c 0.5 c RCS67 4 oz cd 0.7 b-d 1.1 c 1.6 bc Echo fl oz b-d 1.3 b-d 1.4 c 1.9 bc Echo oz b-d 1.1 b-d 1.4 c 2.9 bc Velocity 30 g ai/a b-d 1.1 b-d 1.5 bc 1.3 bc Velocity 45 g ai/a b 1.9 b-d 1.8 bc 3.4 bc Velocity 10 g ai/a bc 2.4 bc 2.0 bc 3.5 bc Velocity 60 g ai/a 8/3 2.0 b-d 2.8 b 3.5 b 4.3 b Control a 10.5 a 11.8 a 13.8 a a Means followed by the same letter do not significantly differ (LSD, p=0.05). b c Treatment not applied. 30

13 Table 22. Preventive Dollar Spot Study on Creeping Bentgrass Quality Rating, Location: Hancock Turfgrass Research Center, E. Lansing, MI Rating Scale a : Turfgrass Quality 0 10, where 10 = best, 0 = worst, and 7= acceptable. Treatment and Rate/1000 sq ft (Days) Mean b,c 9/9 Mean b,c 9/15 Rubigan AS 1.5 oz V SC 0.44 fl oz V SC 0.66 fl oz V WDG oz Velocity 10 g ai/a Velocity 30 g ai/a Velocity 30 g ai/a Velocity 45 g ai/a Velocity 60 g ai/a 1 app Banner Maxx 0.5 fl oz RCS67 4 oz Spectro 4 oz Insignia 0.9 oz Daconil Ultrex 3.2 oz Emerald 0.18 oz Chipco 26GT 4 fl oz Emerald 0.18 oz d na Mean b,c 9/22 Propiconazole Pro 1 oz 15-Jun Curalan 1oz 15-Jul Emerald 0.18 oz 15-Aug Banner Maxx 1 fl oz 24-Jun Chipco 26GT 4 fl oz 15-Jul Daconil Ultrex 3.2 oz 29-Jul Daconil Ultrex 3.2 oz 12-Aug Echo fl oz Echo oz Propiconazole 1.3ME 2 fl oz Control a Ratings based on color, density, and uniformity. b Means followed by the same letter do not significantly differ (LSD, p=0.05). c d Treatment not applied. 31

14 Curative Dollar Spot (Rutstroemia floccosum) on Poa annua This study was set up on an annual bluegrass fairway at the Hancock Turfgrass Research Center on the MSU campus in E. Lansing, MI in four replications of a randomized block design. The plots measured 2 x 6 with 6 alleys. Spray treatments were applied using a CO 2 backpack sprayer set at 38 psi with a single 8002E Tee Jet flat fan nozzle. Spray volume was 1 gallon/1000 sq ft. Plots were irrigated as needed and Country Club fertilizer was applied at 1/8# N/1000 sq ft on 8/27, 9/7, and 9/21. Treatments on a 14 day spray schedule were applied curatively on 8/26, 9/10 and 9/26 while the 28 day treatment was applied on 8/26 and 9/26 (except as noted in the data table). Disease ratings (as % recovery from initial disease levels) were taken on 9/10, 9/23, and 9/29. As the turf recovery data (Table 23) indicate, on day 14 after the initial treatment application, treatments such as Emerald (0.18 oz), V SC, and Rubigan AS (1.5 fl oz) were already promoting significant turfgrass recovery, compared to the untreated control. By the 9/23 rating data, following 2 applications of most treatments, many of the treatments were promoting statistically significant turfgrass recovery compared to the untreated control, in which disease pressure continued to mount. No quality ratings were taken because no non-disease quality differences were existent, with the exception of the Velocity (10 gm ai/a) treatment in which moderate phytotoxicity was noted within a few days after initial treatment application. The higher rate Velocity treatments were so severely damaged that no disease data was available, so these treatments were not included in Table

15 Table 23. Curative Dollar Spot Study on Poa annua, Location: Hancock Turfgrass Research Center, E. Lansing, MI. Rating Scale: Percent recovery from initial dollar spot rating on August 26. Treatment and Rate/1000 sq ft 10-Sep 23-Sep 29-Sep (Days) Mean a,b Mean a,b Mean a,b Cl fl oz 8/ b-e cd e Control a cd c-e Spectro 4 oz a-e 58.9 ab c-e Echo oz a-d 57.0 ab b-e RCS67 4 oz b-e a-d b-d Banner Maxx 1 fl oz 8/ a 8.3 a-d b-d Echo fl oz a-d -1.4 a-d b-d Insignia 0.9 oz a-d 82.1 a -5.2 a-c V SC 0.44 fl oz g 92.2 a 23.3 ab Daconil Ultrex 3.2 oz a-d 87.5 a 29.2 ab Velocity 10 g ai/a e-g 58.3 ab 30.8 ab V SC 0.66 fl oz fg 98.6 a 88.9 a Banner Maxx 0.5 fl oz c-f a 94.2 a Propiconazole 1.3ME 2 fl oz a-d a 97.9 a Rubigan AS 1.5 oz g 93.8 a 98.9 a Emerald 0.18 oz a-d a 99.4 a V WDG oz fg a a Chipco 26GT 4 fl oz a-d b-d a a Means followed by the same letter do not significantly differ (LSD, p=0.05). b 33