CRUCIFER FLEA BEETLE CONTROL WITH INSECTICIDES ALLOWED FOR ORGANIC PRODUCTION, 2013

Abstract

This trial was conducted to evaluate insecticides allowed for organic production. The trial was conducted on a field managed using practices allowed for organic production since 2008 at the New York State Experiment Station in Geneva, NY. An overwintered rapeseed cover crop was plowed under in May. Cabbage (‘Farao’) with 3-4 true leaves was transplanted on 23 May into raised beds with 1.25 mil black polyethylene and drip irrigation. Annual ryegrass was seeded between the rows for weed control. Four treatments and an untreated check were arranged in a RCB with four replications. Each plot consisted of five plants spaced 12 inches apart with 7 ft between rows and 2 ft between treatments. Sprays were applied with a CO2 pressurized backpack sprayer at 40 psi delivering 40 gpa through two TeeJet 8002VS flat fan nozzles spaced 19 inches apart. Treatments included Entrust (spinosad) at 25 oz/acre, Neemix 4.5 (azadirachtin) at 10 oz/acre, Pyganic 5.0 (pyrethrins) at 9 oz/acre, mixture of Neemix and Pyganic (10 and 9 oz/acre), and an untreated control. The first spray was applied 31 May as soon as beetles began invading the plots. Two more sprays were applied on 7 and 14 Jun. On 21 Jun plots were rated for damage using a 1-5 scale, with 1 being no damage and 5 being severe damage with plants nearly dead. Damage ratings were analyzed using the Kruskall-Wallis non-parametric test because of the qualitative nature of the data. Pair-wise Wilcoxon sign-ranked tests were carried out on damage ratings to separate treatments.