Control of Thrips and Aphids on Seedling Cotton with Granular In-Furrow Insecticides and Seed Treat-Ments, 1986

Abstract

Abstract The efficacy of an experimental granular organophosphate insecticide on thrips and cotton aphids was compared to Temik 15G, Furadan 15G, Lance 15G and Orthene 80SP seed treatments at the Northeast Research Station, St. Joseph, LA. Test plots were replicated 4 times in a randomized complete block design, and were 4 rows (40 inch spacing) × 65 ft. Cotton was planted on 30 Apr on a commerce silt loam soil fertilized (pre-plant) with 90 lb N/acre. Test treatments were applied in-furrow at planting with a John Deere 7100 planter, equipped with granular applicator split boxes. Terraclor Super × (Terraclor 1.0 lb + Terrazole 0.25 lb Al/acre) was applied with each granular treatment, and one of the seed treatments, as a standard fungicide treatment. Major pest and/or secondary pest treatments were initiated in Jun and maintained on a 'as needed' basis through Aug. Efficacy of the various treatments on thrips and cotton aphids was measured by washing insects from 10 seedling cotton plants/plot onto 200 mesh screens, backwashing them onto lined filter paper (7 cm) and counting them with the aid of a binocular dissecting microscope. Leaf measurements were made on 5 Jun with a Licor leaf area machine, measuring all leaves from 5 plants/plot that were removed from the field and immediately processed. Stand data were taken from the 2 middle rows of each plot in 20 ft flagged sections on 4 and 20 Jun. Plant height of 20 randomly selected plants within each plot was measured on 4 Jun. Yields were determined by solid picking the 4 row plots with a mechanical harvester on 20 Sep and 7 Oct.