Ovicide-Larvicide Combinations for Bollworm Control, 1980

Stoneville 213 variety cotton was planted May 2 to Memphis silt loam soil at the Ames Plantation, Grand Junction, TN. Four-row plots, 35 ft long were replicated 4 times in a randomized complete block design. The plot was side-dressed on July 1 with 1.5 lb ai/acre of Temik to encourage a bollworm outbreak. The number of bollworm eggs and larvae in terminals exceeded the economic threshold Aug 7. Insecticides were applied Aug 7 and 14 with a 4-row boom at the rate of 9.4 gal of mixture per acre (3 mph, 40 psi, 3 Delavan HB 4 70° nozzles per row) with a CO2-pressurized system mounted on an IH 660 high clearance sprayer. Because of drought conditions, plants were not attractive for bollworm moth oviposition, and further applications were not required after the second. Seasonal pressure by the bollworm was considered light. The two center rows of each plot were machine harvested Oct 3 and 17. Yield data were subjected to analysis of variance.