Efficacy of Chemicals for Control of Cotton Bollworm and Tobacco Budworm, 1978

Stoneville 213 variety was planted on May 17‘78 at the Plant Science Farm of the Mississippi Agricultural and Forestry Experiment Station, Mississippi State, MS. Plots 8 rows wide by 90 ft long were arranged in a randomized complete block design replicated 4 times. Insecticides were applied to the center 4 rows of each plot at the rate of 5 gallons of mixture per acre, 3 mph, 40 psi and 3 nozzles per row. Applications for Heliothis spp. control were made 13 times on a 4 to 5 day schedule from July 19 to September 21‘78. Azinphosmethyl was applied to all plots at 0.25 lb ai/acre 8 times as needed from July 27 to September 25‘78 to control boll weevils, Anthonomusgrandis Boheman. Aldi-carb was applied to all plots at 2 lb ai/acre on June 14 to reduce beneficial arthropods and aggravate a Heliothis spp. outbreak. Plots were examined weekly for Heliothis spp. damage by randomly selecting 25 squares from all parts of the plants along the center 2 rows. The tobacco budworm constituted 54% and 100% of the population on August 16 and September 6, respectively. Yields were estimated by machine picking the center 2 rows on October 10 and 20‘78.