Insecticide Selectivity Trial, 1980

The trial was conducted at the Hortic. Farm, Agrie. Res. Cent., Centre Co., Pa. A randomized complete block design with four replications was used. Plots consisted of six 40 ft long rows. Temik 15G at 1.5 lb (AI)/acre was applied at planting. Green peach aphid (GPA) and potato leafhopper (PLH) populations were sampled weekly starting 14 Jul. A censored sample of GPA on 200 leaves per treatment was made, the density classes being 0, 1, 2, 3, 4, >4 GPA per leaf. Total PLH nymphs per leaf were counted on the same leaves. Two spray schedules were used for each compound. Applications were made either twice, on 31 Jul and 14 Aug., or 5 times, on 25, 31 Jul., 7, 14 and 21 Aug. Chemicals were applied with a boom sprayer in 40 gal water per acre. Two rows in each plot were harvested on 6 Oct.