Evaluation of Fracture fungicide for management of sour rot and ripe rot on wine grapes, 2015

摘要

The test was conducted at the Halbrendt Vineyard, Orrtanna, PA to evaluate the performance of Fracture programs superimposed on a standard maintenance spray program to control sour rot, ripe rot and other rots on wine grapes. The test site was plantedto Vitis interspecific hybrid 'Vidal Blanc" grapevines. The treatments were applied to 8-vine plots arranged in a randomized complete block design with four replications each. The plots were arranged in alternate rows with intermediate rows serving as buffers to prevent spray drift from interfering with the treatments. A standard fungicide / insecticide maintenance program was applied to the entire vineyard using a Jacto Airbus 500 airblast sprayer delivering 67 gal/A at 250 psi, for control of commongrapevine diseases. A single application of Fracture was made at a rate of 1 quart per acre plus one pint Cohere (nonionic spreader / sticker) per acre when grapes reached 11, 14, 19 or 21 brix on 17 Aug, 27 Aug, 11 Sep and 28 Sep. Untreated plots servedas a control. The incidence and severity of sour, ripe and other rots were rated on 25 October. The severity of each disease was determined on 25 clusters per plot using a 0-4 scale where 0, 1, 2, 3, and 4 equal 0, 1-25, 26-50, 51-75, and 76-100% disease severity, respectively. Scale means (0, 13, 38, 63, and 88% for 0, 1, 2, 3, and 4, respectively) were then used to determine treatment means. Data were analyzed using analysis of variance (SAS Institute Inc., Cary, NC).