Thrips Control by Seed Treatment and Foliar Treatments, 1982

A thrips control study was initiated at the Holly Springs Branch of the Miss. Agric. and For. Exp. Stn. on 6 May. Cotton was planted on this date in a split-split plot design with five replications. Whole plot treatments consisted of different varieties of cotton with either: (1) A seed coat treatment of Orthene 80S (8 oz per cwt), (2) an in-furrow application of Tremik 15G (0.975 (AI)/acre) or (3) no insecticide treatment at planting. Sub-plot treatments consisted of 1 foliar insecticide application on 25 May, or no foliar insecticide. The thrips population prior to foliar treatment was a predominantly adult population averaging 0.44 thrips per plant. Foliar treatments were applied through a CO2 back pack delivering 7.1 gal/acre through two TX-4 nozzles per row. Posttreatment counts were taken on 2 June. Few significant differences in the thrips population at this time were detected. Also on this date and on 21 June, 5 plants were removed from each sub-plot. Observations were taken by counting the number of nodes and true leaves, and measuring the root length, hypocotyl length, internode lengths and total plant length. Few significant differences in the thrips population at this time were detected. Significant differences were detected on 2 June in hypocotyl length, number of nodes and 1st internode length. Yield data were taken on 19 Oct. No significant differences were observed in yield.