Potato Insect Control, 1985-Comparative Efficacy of Conventional Vs. Controlled Droplet Application

Potato seed pieces were planted in a Rhinebeck silt loam field on 22 May ’85 at the C.U. Vegetable Research Farm, Freeville, NY. Each plot c onsisted of a 30-ft long row separated by 2 skip-rows. Plots were arranged in a split-plot experimental design with 4 replications. Treatments were applied with: 1) a tractor-mounted hydraulic boom sprayer with 4 hollow cone nozzles delivering 100 gal/acre at 250 PSI, and 2) a tractor-mounted controlled droplet applicator (CDA) sprayer delivering 6.7 gal/acre at 3500 RPM and 20 PSI. Treatments were applied on 25 Jun, 16 Jul, and 27 Aug. Sampling methods and dates were: 1) CPB: no. of live beetles per 10 hills on 24 Jun, 2 Jul; no. of dead beetles per 10 hills on 26, 28 Jun; no. of live larvae per 20 mainstems on 9 Jul; no. of live larvae per 5 mainstems on 17, 30 Jul; 2) aphids: no. per 5 compound leaves (from lower ⅓ of plant) on 11, 17, 30 Jul; no. per 4 compound leaves on 14 Aug; no. per 2 compound leaves on 30 Aug; and 3) PLH: no. per 5 D-vac sampling sites on 15, 18 Jul, 1,15 Aug, and 3 Sep. Weed control, fertilization, and other cultural practices were the same as those normally used in commercial production.