Grape, Season-Long Broad-Spectrum Control, 1994

Insecticides were applied to mature 14 year old grape vines at the Trevor Nichols Research Complex near Fennville, MI at a rate of 50 gpa using a FMC 1029 airblast sprayer. Treatments were arranged in a completely randomized design of single 50-foot-long rows of vines replicated 4 times. Insecticides were applied, as indicated in the table, on the following dates: 4 May (BS), 25 May (1C), 9 Jun (Bloom), 22 Jun (3C), 3 Jul (4C), 17 Jul (5C), 29 Jul (6C), 12 Aug (7C), 25 Aug (8C) and 6 Sep (9C). Second generation grape berry moth application was timed for one wk after sustained catch in pheromone traps. Phytotoxicity damage was rated on the untreated control and the Danitol plots on 22 Jul. Twenty-five leaf samples were rated as clean or damaged. A leaf was rated as damaged if it had spots or blemishes that could not be attributed to disease or insect injury. All damaged leaves had ≤25% of their surface injured. Damage evaluations for grape berry moth, and Japanese beetle were performed on 27 Sep. Damage was assessed by sampling 25 fruit clusters from each replicate. Each cluster was rated for the presence or absence of injury from each of the three insect pests.