Botrytis rot and bunch rot control with new and existing fungicides, conventional and reduced risk /alternative fungicide programs, 2012

摘要

Fungicides were evaluated for control of Botrytis rot and other bunch rots in a vineyard at the Penn State Fruit Research & Extension Center, Biglerville, PA. Treatments were applied to Scott Henry-trained Chardonnay and Cabernet Franc vines. The experiment was arranged in a randomized complete block design, with four replications. An insecticide program was separately applied using an air-blast sprayer delivering 100 gal/A at 400 psi and a standard fungicide program provided season-long control of the common grapevine diseases other than Botrytis bunch rot. Botrytis spp.-specific fungicide treatments were applied using a Bean covered-boom dilute sprayer delivering 50-100 gal/A at 100 psi, depending on the canopy growth. Disease incidence for any visible Botrytis rot or combined black rot and ripe rot was recorded for 25 randomly selected Chardonnay and Cabernet Franc clusters and the same 25 clusters were used to determine disease severity as the percentage of cluster area infected using the Barratt-Horsfall scale and was converted to percent area infected using Elanco conversion tables. Combined data for the two cultivars were analyzed using analysis of variance.