Evaluating Season-Long Fungicide Programs for Dollar Spot Control on Creeping Bentgrass Putting Green Turf, 2017

Transcription

1 Evaluating Season-Long Fungicide Programs for Dollar Spot Control on Creeping Bentgrass Putting Green Turf, 2017 Principal Investigator Joseph Roberts Technical Assistant Getaneh Achenef Treatment Spray Timing 1. Civitas Program 1 14 day Prevent 2. Civitas Program 2 14 day Prevent 3. UMD-DS Program 1 14 day Prevent 4. Civitas Program 3 14 day Prevent 5. Civitas Program 4 14 day Prevent 6. Civitas Program 5 21 day Prevent 7. UMD-DS Program 2 21 day Prevent 8. Kabuto 0.50 fl oz/1000 ft2 14 day Prevent 9. Kabuto 3.0 fl oz/1000 ft2 14 day Prevent 10. Lexicon 0.34 fl oz/1000 ft2 14 day Prevent 11. UMD-DS Program 3 14 day Prevent 12. UMD-DS Program 4 14 day Prevent 13. UMD-DS Program 5 14 day Prevent 14. UMD-DS Program 6 21 day Prevent 15. Non-treated control Civitas Prog. 1 2 May (Civitas one 17 fl oz + Interface 3.0 fl oz), 16 May (Civitas one 17 fl oz), 30 May (Civitas one 17 fl oz + Emerald 0.13 oz), 13 June (Civitas one 8.5 fl oz), 27 June (Civitas one 8.5 fl oz + Iprodione 3 fl oz), 13 July (Civitas one 8.5 fl oz), 25 July (Civitas one 8.5 fl oz + Insignia SC 0.4 fl oz), 08 Aug (Civitas one 8.5 fl oz), 22 Aug (Civitas one 8.5 fl oz + Secure 0.5 fl oz) Civitas Prog. 2 2 May (Civitas one 8.5 fl oz + Interface 3.0 fl oz), 16 May (Civitas one 8.5 fl oz), 30 May (Civitas one 8.5 fl oz + Emerald 0.13 oz), 13 June (Civitas one 8.5 fl oz), 27 June (Civitas one 8.5 fl oz + Iprodione 3 fl oz), 13 July (Civitas one 8.5 fl oz), 25 July (Civitas one 8.5 fl oz + Insignia SC 0.4 fl oz), 08 Aug (Civitas one 8.5 fl oz), 22 Aug (Civitas one 8.5 fl oz + Secure 0.5 fl oz) UMD-DS Prog 1 2 May (Interface 3.0 fl oz), 16 May (Secure 0.5 fl oz), 30 May (Emerald 0.13 oz), 13 June (Briskway 0.5 fl oz), 27 June (Iprodione 3 fl oz), 13 July (Secure 0.5 fl oz), 25 July (Insignia 0.4 fl oz), 08 Aug (Emerald 0.13 oz), and 22 Aug (Secure 0.5 fl oz) Civitas Prog. 3 2 May (Civitas one 17 fl oz), 16 May (Civitas one 17 fl oz), 30 May (Civitas one 17 fl oz + Emerald 0.13 oz), 13 June (Civitas one 8.5 fl oz), 27 June (Civitas one 8.5 fl oz + Iprodione 3 fl oz), 13 July (Civitas one 8.5 fl oz), 25 July (Civitas one 8.5 fl oz + Insignia SC 0.4 fl oz), 08 Aug (Civitas one 8.5 fl oz), 22 Aug (Civitas one 8.5 fl oz + Secure 0.5 fl oz) Civitas Prog. 4 2 May (Civitas one 8.5 fl oz), 16 May (Civitas one 8.5 fl oz), 30 May (Civitas one 8.5 fl oz + Emerald 0.13 oz), 13 June (Civitas one 8.5 fl oz), 27 June (Civitas one 8.5 fl oz + Iprodione 3 fl oz), 13 July (Civitas one 8.5 fl oz), 25 July (Civitas one 8.5 fl oz + Insignia SC 0.4 fl oz), 08 Aug (Civitas one 8.5 fl oz), 22 Aug (Civitas one 8.5 fl oz + Secure 0.5 fl oz) Civitas Prog. 5 2 May (Civitas one 12 fl oz), 23 May (Civitas one 12 fl oz), 13 June (Civitas one 8.5 fl oz + Emerald 0.13 oz), 50 July (Civitas one 8.5 fl oz + Secure 0.5 fl oz), 25 July (Civita one 8.5 fl oz + Iprodione 3 fl oz), 17 Aug (Civitas one 8.5 fl oz + Insignia 0.4 fl oz + Daconil Ultrex 1.8 zo)

2 UMD-DS Prog 2 2 May (Bayleton 0.25 fl oz + Daconil Ultrex 1.8 oz), 23 May ( fl oz), 13 June (Emerald 0.13 oz), 05 July (Secure 0.5 fl oz), 25 Aug (Iprodione 3 fl oz), 17 Aug (Insignia 0.4 fl oz + Daconil Ultrex 1.8 oz) UMD-DS Prog 3-2 May (Emerald 0.13 oz), 16 May (Trinity 1.0 fl oz +Daconil Ultrex 3.2 oz), 30 May (Lexicon 0.34 fl oz), 13 June (Trinity 1.0 fl oz +Daconil Ultrex 3.2 oz), 27 June (Lexicon 0.34 fl oz), 13 July (Cleary s oz), 25 July (Honor Intrinsic 0.83 oz), 08 Aug (Subdue 1.0 fl oz + Velista 0.5 oz), 22 Aug (Lexicon Intrinsic 0.34 fl oz) UMD-DS Prog 4-2 May (Banner Maxx 0.5 fl oz), 16 May (Secure 0.5 fl oz), 30 May (Banner Maxx 0.5 fl oz), 13 June (Velista 0.3 oz), 27 June (Daconil Ultrex 3.2 oz + Heritage Action 0.5 oz), 13 July (Briskway 0.5 fl oz), 25 July (Velista 0.3 oz), UMD-DS Prog 5-2 May (Bayleton 0.5 fl oz), 16 May (Chipco 26GT 2 oz), 30 May (Bayleton 0.5 fl oz), 13 June (Exteris Stressgard 3.0 fl oz), 27 June (Daconil Ultrex 3.2 oz + Signiture Plus 4.0 oz), 13 July (Interface 4 fl oz), 25 July (Lexicon 0.34 fl oz), UMD-DS Prog 6-2 May (Bayleton 0.25 fl oz + Daconil Ultrex 1.8 oz), 23 May ( fl oz), 13 June (Emerald 0.18 oz), 05 July (Secure 0.5 oz), 25 July (Interface 3 fl oz), 17 Aug (Insignia 0.4 fl oz + Daconil Ultrex 1.8 oz) Fungicide programs were evaluated for their effect on dollar spot, caused by Sclerotinia homoeocarpa. This trial was conducted at the Paint Branch Turfgrass Research Facility in College Park, MD on 007 creeping bentgrass maintained as a putting green. Mowing was performed 5 times weekly at a height of in. Rolling was performed 3 times a week using a Salsco sidewinder beginning from early- June. The site was irrigated to prevent drought stress and water infiltration was maintained with Fleet (i.e., polyoxalkylene polymers) applications using label recommendations. The experimental site received 3.0 lb. N 1000 ft -2 over the course of the growing season. Insect pests were controlled with Talstar (i.e. Bifenthrin) at 0.5 fl oz 1000 ft -2 on 12 June. Treatments were arranged in a randomized complete block design with 4 replications. Treatments were applied to 3 x 6 plots using TeeJet AI9508E (2 gal 1000 ft -2 ) air induction nozzles powered by a CO2 pressurized backpack sprayer. All treatments were initiated on 02 May; treatments having a 14 d application schedule were reapplied on 16 and 30 May, 13 and 27 June, 13 and 25 July, 8 and 22 Aug.; and treatments having a 21 d were re-applied on 23 May, 13 June, 05 and 25 July, and 17 Aug. The experimental area was evaluated every 7-14 days and ratings included dollar spot Infection centers, turf quality (scale 1-9: 1=dead, 9=best, and 6=minimum acceptable), and turf color using NDVI. Yellow spot infection centers were also rated when symptoms developed mid-season. Dollar spot disease developed naturally in May and increased throughout June. All programs significantly reduced dollar spot development throughout the growing season compared to the non-treated control after the second application. Programs having 21 d application intervals had slightly more disease than 14 d programs on multiple rating dates and when comparing AUDPC, although disease development in these treatments was often significantly less than the non- treated check. Yellow spot (Cyanobacteria sp.) also developed as a significant issue in early July; plots previously treated with Lexicon across the season exhibited the most yellow spot across all 3 rating dates. Turf quality results followed similar trends with disease ratings and all products improved turf quality when compared to the non-treated check. Turf color ratings were also similar to turf quality ratings but effects were minimal across the season.

3 Table 1. Influence of fungicide programming on dollar spot disease caused by Sclerotinia homoeocarpa in creeping bentgrass putting green turf Dollar Spot Disease (# ICs plot -1 ) Civitas Program 1 14 day 25.3 z a 12.0 a 5.3 a 14.7 abc 0.8 ef 0.3 d 0.0 d Civitas Program 2 14 day 20.5 a 12.0 a 3.7 a 10.9 bc 4.3 def 1.1 cd 0.0 d UMD-DS Program 1 14 day 15.8 a 11.5 a 6.7 a 13.3 abc 12.3 cd 1.2 cd 0.4 d Civitas Program 3 14 day 17.5 a 10.3 a 5.2 a 11.2 bc 0.9 ef 0.2 d 0.0 d Civitas Program 4 14 day 16.0 a 7.8 a 5.7 a 14.2 abc 6.4 de 0.0 d 0.0 d Civitas Program 5 21 day 23.3 a 8.8 a 6.1 a 9.2 bc 21.6 bc 16.2 ab 0.5 d UMD-DS Program 2 21 day 25.0 a 10.0 a 8.9 a 29.8 a 48.9 a 36.9 a 7.3 b Kabuto 0.50 fl oz/1000 ft2 14 day 28.8 a 16.5 a 7.0 a 12.3 bc 9.0 cd 1.2 cd 0.0 d Kabuto 3.0 fl oz/1000 ft2 14 day 18.8 a 11.0 a 3.9 a 0.4 de 0.0 f 0.0 d 0.0 d Lexicon 0.34 fl oz/1000 ft2 14 day 24.8 a 9.5 a 2.6 a 0.1 e 0.0 f 0.0 d 0.0 d UMD-DS Program 3 14 day 17.3 a 10.5 a 3.3 a 5.2 cde 3.3 def 0.4 d 0.0 d UMD-DS Program 4 14 day 19.0 a 8.0 a 3.1 a 4.0 cde 2.9 def 2.8 c 0.5 d UMD-DS Program 5 14 day 18.3 a 8.3 a 3.2 a 7.0 cd 8.6 cd 3.0 c 0.3 d UMD-DS Program 6 21 day 20.8 a 8.8 a 2.6 a 9.5 bc 22.0 bc 13.8 b 2.8 c Non-treated control 19.8 a 12.8 a 5.1 a 23.0 ab 39.4 ab 27.0 ab 49.0 a Treatment NS NS NS * * * * Y Treatments were applied at the specified intervals from 02 May 2017 using a CO2 backpack sprayer equipped with a Teejet AI9508E nozzle. Z Values are means of 4 replicates. Means within columns followed by the same letter are not significantly different according to LSD test (p<0.05)

4 Table 1. cont. Influence of fungicide programming on dollar spot disease caused by Sclerotinia homoeocarpa in creeping bentgrass putting green turf Treatment X and Rate 1000 ft 2 Dollar Spot Disease (# ICs plot -1 ) AUDPC Y Civitas Program 1 14 day 0.0 Z d 1.3 d-g 0.0 d 22.8 d 22.3 cde def Civitas Program 2 14 day 0.2 d 0.6 efg 0.0 d 11.1 de 14.4 def fgh UMD-DS Program 1 14 day 0.2 d 0.4 fg 0.2 cd 5.4 ef 10.2 ef efg Civitas Program 3 14 day 0.0 d 0.7 efg 0.0 d 13.2 de 21.4 cde fgh Civitas Program 4 14 day 0.0 d 0.2 fg 0.0 d 10.4 de 13.3 def fgh Civitas Program 5 21 day 2.8 c 0.9 d-g 0.0 d 51.1 c 6.5 f cd UMD-DS Program 2 21 day 17.7 b 1.8 c-f 1.1 bc 83.7 b 27.2 cd d Kabuto 0.50 fl oz/1000 ft2 14 day 0.0 d 2.8 b-e 1.4 b 9.8 de 25.7 cd c-f Kabuto 3.0 fl oz/1000 ft2 14 day 0.0 d 0.2 fg 0.0 d 0.0 f 0.3 g h Lexicon 0.34 fl oz/1000 ft2 14 day 0.0 d 0.0 g 0.2 cd 0.4 f 0.9 g gh UMD-DS Program 3 14 day 0.0 d 0.6 efg 0.0 d 0.0 f 0.2 g gh UMD-DS Program 4 14 day 0.0 d 7.3 b 1.2 bc 66.3 bc 95.0 ab cd UMD-DS Program 5 14 day 0.0 d 5.4 bc 0.0 d 46.1 c 45.3 bc cde UMD-DS Program 6 21 day 5.8 c 3.6 bcd 1.0 bc 68.9 bc 23.1 cd bc Non-treated control 88.1 a a a a a a Treatment * * * * * * X Treatments were applied at the specified intervals from 02 May 2017 using a CO2 backpack sprayer equipped with a Teejet AI9508E nozzle. Y Area under disease progress curve (AUDPC) values were calculated using the trapezoidal method as defined by Madden et al., Z Values are means of 4 replicates. Means within columns followed by the same letter are not significantly different according to LSD test (p<0.05)

5 Table 2. Influence of fungicide programming on yellow spot of creeping bentgrass putting green turf Yellow Spot Civitas Program 1 14 day 7.2 Z bcd 3.4 a-d 1.1 cd Civitas Program 2 14 day 4.6 cd 1.4 c-f 0.3 cd UMD-DS Program 1 14 day 14.4 ab 8.5 ab 7.3 ab Civitas Program 3 14 day 2.4 def 1.5 c-f 0.7 cd Civitas Program 4 14 day 4.5 cd 3.3 a-d 2.1 bcd Civitas Program 5 21 day 2.1 def 1.2 def 0.7 cd UMD-DS Program 2 21 day 6.5 bcd 2.2 b-e 1.1 cd Kabuto 0.50 fl oz/1000 ft2 14 day 12.8 abc 3.0 bcd 2.1 bc Kabuto 3.0 fl oz/1000 ft2 14 day 3.7 de 1.0 def 0.5 cd Lexicon 0.34 fl oz/1000 ft2 14 day 20.3 a 12.5 a 9.4 a UMD-DS Program 3 14 day 0.1 ef 0.0 f 0.0 d UMD-DS Program 4 14 day 1.7 def 0.7 def 1.1 cd UMD-DS Program 5 14 day 0.0 f 0.2 ef 0.0 d UMD-DS Program 6 21 day 7.2 bcd 6.3 abc 1.7 bcd Non-treated control 6.1 bcd 1.1 def 0.0 d Treatment * * * Y Treatments were applied at the specified intervals from 02 May 2017 using a CO2 backpack sprayer equipped with a Teejet AI9508E nozzle. Z Values are means of 4 replicates. Means within columns followed by the same letter are not significantly different according to LSD test (p<0.05)

6 Table 3. Influence of fungicide programming on turf quality of creeping bentgrass putting green turf Turf Quality (1-9; 9=best) Civitas Program 1 14 day 5.50 z a 5.63 a 6.50 a 5.75 a-d 6.25 abc 6.25 ab 7.00 a Civitas Program 2 14 day 5.38 a 5.50 a 6.13 a 5.88 abc 6.38 ab 6.38 ab 7.00 a UMD-DS Program 1 14 day 5.25 a 5.25 a 5.63 a 5.75 a-d 5.38 def 6.13 ab 6.25 bc Civitas Program 3 14 day 5.50 a 5.50 a 6.10 a 5.50 cde 6.13 abc 6.25 ab 6.75 ab Civitas Program 4 14 day 5.50 a 5.75 a 6.35 a 5.50 cde 5.75 b-e 6.13 ab 6.25 bc Civitas Program 5 21 day 5.38 a 5.63 a 6.13 a 6.00 abc 5.13 efg 5.50 cd 6.50 ab UMD-DS Program 2 21 day 5.25 a 5.13 a 5.63 a 5.00 e 4.25 h 4.63 f 5.50 d Kabuto 0.50 fl oz/1000 ft2 14 day 5.50 a 5.00 a 5.63 a 5.50 cde 5.63 c-f 6.25 ab 6.38 b Kabuto 3.0 fl oz/1000 ft2 14 day 5.25 a 5.38 a 5.75 a 6.25 ab 6.63 a 6.25 ab 6.63 ab Lexicon 0.34 fl oz/1000 ft2 14 day 5.50 a 5.50 a 6.00 a 6.38 a 6.63 a 6.50 a 6.75 ab UMD-DS Program 3 14 day 5.63 a 5.25 a 5.75 a 5.88 abc 6.13 abc 6.13 ab 6.75 ab UMD-DS Program 4 14 day 5.38 a 5.25 a 5.63 a 5.88 abc 5.88 bcd 5.88 bc 6.38 b UMD-DS Program 5 14 day 5.25 a 5.25 a 5.98 a 5.63 b-e 5.38 def 5.50 cd 6.25 bc UMD-DS Program 6 21 day 5.38 a 5.25 a 5.88 a 5.63 b-e 5.00 fg 5.25 de 5.75 cd Non-treated control 5.13 a 5.25 a 5.50 a 5.13 de 4.50 gh 4.88 ef 4.25 e Treatment NS NS NS * * * * Y Treatments were applied at the specified intervals from 02 May 2017 using a CO2 backpack sprayer equipped with a Teejet AI9508E nozzle. Z Values are means of 4 replicates. Means within columns followed by the same letter are not significantly different according to LSD test (p<0.05)

7 Table 3. cont. Influence of fungicide programming on turf quality of creeping bentgrass putting green turf Treatment X and Rate 1000 ft 2 Turf Quality (1-9; 9=best) AUQPC Y Civitas Program 1 14 day 6.88 z ab 7.13 ab 6.88 a 6.13 cd 5.88 d-g a Civitas Program 2 14 day 7.25 a 7.25 a 6.88 a 6.88 ab 6.38 bcd a UMD-DS Program 1 14 day 6.13 de 6.63 bcd 6.25 b 6.38 bc 6.25 cde cde Civitas Program 3 14 day 6.88 ab 7.13 ab 6.88 a 6.38 bc 5.98 c-f a Civitas Program 4 14 day 6.50 bcd 7.25 a 6.25 b 6.35 bc 6.13 c-f a-d Civitas Program 5 21 day 5.88 ef 6.75 a-d 6.88 a 5.50 de 6.13 c-f bcd UMD-DS Program 2 21 day 5.25 g 6.63 bcd 6.75 ab 5.00 e 5.63 fg f Kabuto 0.50 fl oz/1000 ft2 14 day 6.13 de 6.38 cd 6.38 ab 6.38 bc 5.88 d-g cde Kabuto 3.0 fl oz/1000 ft2 14 day 6.38 b-e 6.88 abc 6.63 ab 6.63 abc 6.50 bc abc Lexicon 0.34 fl oz/1000 ft2 14 day 6.88 ab 6.63 bcd 6.35 ab 7.00 ab 6.88 ab a UMD-DS Program 3 14 day 6.63 bcd 6.88 abc 6.63 ab 7.13 a 7.38 a ab UMD-DS Program 4 14 day 6.25 cde 6.25 d 6.73 ab 5.50 de 4.88 h de UMD-DS Program 5 14 day 6.75 abc 6.25 d 6.50 ab 5.63 de 5.38 gh de UMD-DS Program 6 21 day 5.38 fg 6.38 cd 6.38 ab 5.25 e 5.75 efg ef Non-treated control 4.00 h 3.75 e 4.00 c 3.75 f 3.63 i g Treatment * * * * * * X Treatments were applied at the specified intervals from 02 May 2017 using a CO2 backpack sprayer equipped with a Teejet AI9508E nozzle. Y Area under disease progress curve (AUDPC) values were calculated using the trapezoidal method as defined by Madden et al., Z Values are means of 4 replicates. Means within columns followed by the same letter are not significantly different according to LSD test (p<0.05)

8 Table 4. Influence of fungicide programming on turf color of creeping bentgrass putting green turf Turf Color (NDVI) Civitas Program 1 14 day 0.71 z a 0.75 a 0.82 a 0.84 a 0.81 d 0.75 a 0.82 abc Civitas Program 2 14 day 0.72 a 0.75 a 0.81 ab 0.85 a 0.82 a-d 0.75 a 0.83 ab UMD-DS Program 1 14 day 0.71 a 0.74 ab 0.80 a-d 0.86 a 0.83 ab 0.75 a 0.82 abc Civitas Program 3 14 day 0.71 a 0.74 ab 0.81 ab 0.84 a 0.81 d 0.74 a 0.82 abc Civitas Program 4 14 day 0.72 a 0.73 abc 0.80 a-d 0.85 a 0.82 a-d 0.74 a 0.82 bc Civitas Program 5 21 day 0.72 a 0.74 ab 0.80 a-d 0.86 a 0.82 bcd 0.75 a 0.81 cd UMD-DS Program 2 21 day 0.71 a 0.72 bcd 0.79 bcd 0.85 a 0.82 bcd 0.74 a 0.81 bcd Kabuto 0.50 fl oz/1000 ft2 14 day 0.72 a 0.73 bcd 0.80 a-d 0.85 a 0.83 ab 0.76 a 0.82 bcd Kabuto 3.0 fl oz/1000 ft2 14 day 0.71 a 0.71 cd 0.79 b-e 0.84 a 0.82 a-d 0.74 a 0.81 bcd Lexicon 0.34 fl oz/1000 ft2 14 day 0.72 a 0.72 bcd 0.80 abc 0.84 a 0.83 abc 0.75 a 0.82 abc UMD-DS Program 3 14 day 0.72 a 0.72 cd 0.78 cde 0.85 a 0.83 a 0.75 a 0.84 a UMD-DS Program 4 14 day 0.70 a 0.71 cd 0.77 e 0.84 a 0.81 cd 0.73a 0.82 bcd UMD-DS Program 5 14 day 0.71 a 0.71 d 0.78 de 0.84 a 0.81 d 0.74 a 0.82 bc UMD-DS Program 6 21 day 0.71 a 0.73 abc 0.79 b-e 0.84 a 0.82 a-d 0.75 a 0.81 cd Non-treated control 0.70 a 0.73 bcd 0.79 b-e 0.84 a 0.81 d 0.74 a 0.80 d Treatment NS * * * * * * Y Treatments were applied at the specified intervals from 02 May 2017 using a CO2 backpack sprayer equipped with a Teejet AI9508E nozzle. Z Values are means of 4 replicates. Means within columns followed by the same letter are not significantly different according to LSD test (p<0.05)

9 Table 4. Cont. Influence of fungicide programming on turf color of creeping bentgrass putting green turf Turf Color (NDVI) AUCPC X Civitas Program 1 14 day 0.81 z ab 0.79 ab 0.80 ab a Civitas Program 2 14 day 0.80 b 0.81ab 0.80 ab a UMD-DS Program 1 14 day 0.81 ab 0.80 ab 0.81 ab a Civitas Program 3 14 day 0.80 b 0.79 ab 0.81 ab a Civitas Program 4 14 day 0.80 b 0.79 b 0.80 ab a Civitas Program 5 21 day 0.80 b 0.79 ab 0.78 c a UMD-DS Program 2 21 day 0.82 a 0.80 ab 0.81 ab a Kabuto 0.50 fl oz/1000 ft2 14 day 0.81 ab 0.80 ab 0.81 ab a Kabuto 3.0 fl oz/1000 ft2 14 day 0.81 ab 0.80 ab 0.80 ab a Lexicon 0.34 fl oz/1000 ft2 14 day 0.81 ab 0.81 a 0.81 ab a UMD-DS Program 3 14 day 0.81 ab 0.80 ab 0.81 a a UMD-DS Program 4 14 day 0.81 ab 0.81 a 0.80 ab a UMD-DS Program 5 14 day 0.81 ab 0.80 ab 0.80 b a UMD-DS Program 6 21 day 0.81 ab 0.80 ab 0.79 bc a Non-treated control 0.77 c 0.76 c 0.74 d a Treatment * * * NS X Treatments were applied at the specified intervals from 02 May 2017 using a CO2 backpack sprayer equipped with a Teejet AI9508E nozzle. Y Area under disease progress curve (AUDPC) values were calculated using the trapezoidal method as defined by Madden et al., Z Values are means of 4 replicates. Means within columns followed by the same letter are not significantly different according to LSD test (p<0.05)