Cooperative Research Project, Doug Gubler, U.C. Davis Dept. of Plant Pathology Final report Trial name... Grape bunch rot fungicide trial, 00 Location... Valley Foothills Vineyard, Philo, Mendocino County, C 95466 Investigators... Doug Gubler, 50.75.004; Ken Dell, Eugene Erickson 50.75.498 Cooperators... Ted Bennett and Jim Klein, avarro Vineyards Dave Olson, Valley Foothills Vineyard Crop... Grape, Johannesburg Riesling Disease... Bunch Rot, Botrytis cinerea Trial layout and method Objective... Efficacy of fungicides for control of Botrytis bunch rot Experimental design... Treatments are field applications to 4 vine plots, in a randomized complete block design, with 4 replications. pplication method... high pressure hand gun sprayer Vine spacing... 8 Row spacing... Treatment unit... 4 vines Treatment unit area... 84 sq ft rea/treatment, sq ft... 56 rea/treatment, acre... 0.0567 Vol. Water/acre, gal... - 4 Vol. water/trt, L... 5. 8.9 pps timing... =bloom; B=close; C=veraison; D= preharvest ( if needed) Treatment interval... pprox weeks Evaluation stage... immediately prior to harvest Treatments protocol # Color Materials Timing FP/ Tol W Untreated OD Rovral 50WP.0 lb BCD 0.7 oz GD V-06.67SC BCD 6. floz 4 W/R V-06.67SC BCD 8.0 floz 5 W/G V-04.67FL BCD.8 floz 6 WOC V-04.67FL BCD 6.8 floz 7 W/B Pristine 8WG BCD.44 lb 8 OBKD Stylet Oil BCD.0 % 9 BKC Stylet Oil + BCD.0 % 5 oz 0 /BK BCD 5 oz W/BK Elite 45DF C BD.5 oz.0 oz WBKC Spiroxamine 00 BC D 8.0.0 4.0 foz oz oz W/O C 0 oz 4 WBC.0 oz BCD.0 oz 5 B Scala 60SC BCD 8.0 foz 6 RD BCD 7 PPC BCD.0 oz 8 O/BK B C D 0.7 oz.0 oz otes:. Tol indicates whether all products in the treatment have an EP tolerance for grapes, and the crop can be harvested.
Materials list Sponsor Product ctive Ingr. Conc. Tol Mfr BSF Pristine 8WG Latron B-956 BS56 on-ionic surfactant 8% BSF Dowgro Spiroxamine 00SC Spiroxamine Tebuconazole Trifloxystrobin 00 g/l 45% 50% Scala 60SC Pyrimethinal 60 g/l JMS Stylet Oil Mineral oil Cyprodinil 99% 75% JMS Syngenta Syngenta Cyprodinil 75% Syngenta Valent V-06.67SC V-06 Valent Lab V-04.67FL V-04 Iprodione Cyprodinil 50% 75% Valent Syngenta pplication schedule Date... 8 Jun 0 7 Jul 0 6 ug 0 7 ug 0 pp.#... B C C Stage... BBCH 68 BBCH 75-79 BBCH 8- BBCH 8-85 85 Vol/trt... 5L 5L 0L 0L Trt# ---- ---- ---- Rovral 50 6 g Rovral 75 0.7 g Rovral 75 0.7 g V-06 6.4 ml V-06 6.4 ml V-06 6.4 ml 4 V-06 8.6 ml V-06 8.6 ml V-06 8.6 ml 5 V-04 4.4 ml V-04 4.4 ml V-04 4.4 ml 6 V-04 8.0 ml V-04 8.0 ml V-04 8.0 ml 7 Pristine. g Pristine. g Pristine. g 8 Stylet Oil 5 ml Stylet Oil 5 ml Stylet Oil 89 ml 9 Stylet Oil + 5 ml Stylet Oil + 5 ml Stylet Oil + 89 ml 0.5 g.0 g.0 g KWG 468 8.8 ml.0 g.0 g 0.0 g -- 0.0 g 4.0 g.0 g 5 Scala 60SC 8.8 ml Scala 60SC 8.8 ml Scala 60SC 8.8 ml 6 7 8 Rovral 75 0.7 g Rovral 75 0.7 g
Calendar of events Date ctivity KD, EE, app. #; :45-:5PM; 68F; clear, 5-8 mph W wind; BBCH 6-69 (mostly 68). o disease 8 Jun observed. 7 Jul EE; checked berries for progress, BBCH 7 7 Jul EE app. #; 9:00M-:0PM; 66-80F; clear, calm-0 mph W breeze; BBCH 75-79 6 ug EE; checked berries, BBCH 8; symptomatic berries in one check cluster. ug EE; checked berries, BBCH 8; symptomatic berry on an unsprayed vine in Row 0 on the hillside 7 ug EE; checked berries, BBCH 8-8 6 ug KD, EE app. #, 0am pm, clear, calm; BBCH 8-85. Pump gearbox break, 5 trts unfinished. 7 ug KD, app # finish, pm pm; clear, calm. Sep rain 9 Sep rain 9 Sep Chuck Olson: berries at 7 Brix; Jim Klein: harvest in about wks 9 Sep Chuck: berries at.5 Brix, probably harvest between and 6 Oct EE, KD, Connie, José; rate 45 clusters/rep, drop crop (GD, W/R, W/G, WOC, WBKC, B, RD, PPC, Oct O/BK), remove flags. Harvest to start Oct. Results and discussion Disease was first observed in ugust, and remained at low levels during the trial. The plots were rated as close to harvest as possible, on Oct. with harvest set to begin within a couple of days. n average of.6% of each cluster surface in untreated plots was infected with Botrytis grey mold. Treatments were not a significant effect on fruit bunch rot severity or incidence, according to OV, p0.05, when all treatments were analyzed together (Table ). However, when five treatments were excluded from the analysis due to high variability, the remaining data set showed significant treatment effects according to OV, p0.05, and the means were separated by Fisher s LSD t Test at p0.05 (Table ).
Table. Grape bunch rot fungicide trial, results of all treatments. # Materials, rate/ Timing Severity Incidence Untreated....64.8 Rovral 50WP, lb, 9.7 oz BC....55 8.9 V-06.67SC, 6. foz BC....86 4.4 4 V-06.67SC, 8.0 foz BC... 0.66 6. 5 V-04.67FL,.8 foz BC... 0.65 7. 6 V-04.67FL, 6.8 foz BC... 0.60 9.6 7 Pristine 8WG,.44 lb BC... 0.8. 8 Stylet Oil, % BC....46.9 9 Stylet Oil, % + Vangard, 5.0 oz BC.... 0.0 0 Vangard, 5.0 oz BC....6 6.,.5 oz Elite 45DF,,.0 oz B C... 0.79.9 Spiroxamine 00, 8 foz,.0 oz BC....64.7 Vangard, 0.0 oz C... 0.90.9 4.0 oz.0 oz BC... 0.97 6. 5 Scala 60SC, 8.0 foz BC... 0.80.7 6 Scala 60SC, +, 4 oz BC... 0.69 6.7 7 Scala 60SC, +,.0 oz BC... 0.86. 8 Scala 60SC, +, 0.7 oz Scala 60SC, +,.0 oz B C... 0.68 5.0 Treatments were applied at bloom (), berry touch (B), and veraison (C). Forty-five clusters per replicate plot were rated for percent of surface area with symptoms of grey mold rot; severity is the average percent cluster surface area infected. Incidence is the percent of clusters rated with any Botrytis grey mold infection. 4
Table. Grape bunch rot fungicide trial, results of a subset of treatments which was analyzed for statistical differences. # Materials, rate/ Timing Severity Incidence 6 V-04.67FL, 6.8 foz BC... 0.47 d 45 9.6 de 5 5 V-04.67FL,.8 foz BC... 0.55 cd 7. e 4 V-06.67SC, 8.0 foz BC... 0.6 cd 6. abcd 6 Scala 60SC, +, 4 oz BC... 0.6 cd 6.7 abcd 8 Scala 60SC, +, 0.7 oz Scala 60SC, +,.0 oz B C... 0.66 cd 5.0 bcde 7 Pristine 8WG,.44 lb BC... 0.7 bcd. cde 7 Scala 60SC, +,.0 oz BC... 0.7 bcd. cde,.5 oz Elite 45DF,,.0 oz B C... 0.77 bcd.9 cde Vangard, 0.0 oz C... 0.80 bcd.9 cde Rovral 50WP, lb, 9.7 oz BC.... abcd 8.9 abc 0 Vangard, 5.0 oz BC....0 abc 6. abcd Untreated....50 ab.8 ab 8 Stylet Oil, % BC....9 a.9 a Fisher s Least Significant Difference... 8.66 Treatments were applied at bloom (), berry touch (B), and veraison (C). Forty-five clusters per replicate plot were rated for percent of surface area with symptoms of grey mold rot; severity is the average percent cluster surface area infected. Incidence is the percent of clusters rated with any Botrytis grey mold infection. 4 Severity values were log (y+) transformed prior to statistical analysis due to heterogeneity of variance; values shown are back-transformed. 5 Values in a column with the same letter are not significantly different according to Fisher s protected LSD t Test, p0.05. 5