Comparison of Soil Treatments for Control of M. Persicae and L. Decemlineata. 1976

On April 16, 1976, ‘Russet Burbank’ potatoes were planted in open furrows inRitzville silt loam soil at Yakima, Washington. The granular insecticides were dribbled through a hand-operated, funnel-type applicator in the furrow over the potato seed pieces; in another series of plots the sprays of insecticide wettable powders were applied in 20 gallons of spray per acre (30.5 liters/ha) in the furrow over potato seed pieces with an experimental CO2 sprayer. After the furrow treatments, the seed pieces were covered with soil. On June 1, when about 75% of the plants had emerged, in another series of plots, granular insecticides were sidedressed with a tractor-mounted Gandyapplicator in 1-inch (2.5-cm)bands, 4inches (10.1 cm) to each side and about the same depth of the potato seed pieces. The plots were 2 rows wide, 34 inches (0.86 m) apart,and50ft (15.2 m) long and replicated 3 times in a randomized complete block design.