Chemical Control of the Cotton Bollworm and Tobacco Budworm in Oklahoma 1985

Abstract

Abstract This test was conducted at the South Central Research Station, Chickasha, OK. The cotton cultivar Stoneville 213 was planted on 29 May at a rate of 20 lb/acre. A randomized complete block design with 3 replications was utilized with plots containing 8 rows, 200 feet long. Spray applications were made with a John Deere Hi-Cycle 6000 sprayer traveling at 4.5 mph. The John Deere pumping unit was replaced with a Marco system equipped with a roller pump and powered by a 3 horsepower Briggs and Straton engine. Chemical applications were made using 1 hollow cone nozzle (spraying systems No. 8) per row with an output of 5 gal/acre at 40 psi. Three insecticide applications were made starting on 24 Jul followed by 1 Aug and 21 Aug. Treatments were to be applied on weekly intervals, however rainfall for the month of August made this impossible. Rainfull during this period was measured in inches and is as follows: 22 Jul, 0.04; 25 Jul, 0.07; 26 Jul, 0.22; 5 Aug, 1.06; 7 Aug, 1.65; 14 Aug, .78; 15 Aug, 0.08; for a total of 3.9 inches. Damage estimates were made by collecting at random 100 fruits from the upper one third of the plants in each plot.