Lesser Cornstalk Borer Control in Grain Sorghum, 1983

Abstract

Abstract Two experiments were planted (36-inch rows) on 31 Aug (Test l)and 20 Sep (Test 2) in Spalding Co, GA. The soil type was a Cecil loamy clay soil. Materials were applied 2 days after each planting in randomized complete blocks with 4 replicates. Liquid formulations were applied in a 7-inch band over the row with a 2-gal hand sprayer equipped with a pressure gauge and a cone nozzle. All liquids were applied at 20 gal/acre at 30 psi, and application speed was regulated with a stopwatch. Granular formulations were applied in a 7-inch band over the row with a hand pushed granular applicator equipped with a 4-inch bander. Partial incorporation of materials was attained by lightly spreading soil from the edge of the rows over the treated bands. Data were collected from 2-row × 28-ft plots which were separated on each side by a border row which received the same treatment. The numbers of healthy and lesser cornstalk borer-(LCB) damaged plants were counted in each plot ca. 2 and 6 weeks after planting (14 and 42 days in Test 1, 18 and 41 days in Test 2). Each plant with LCB damage was identified by characteristic damage symptoms (dead or dying central whorl, or complete wilting) and also by the presence of LCB larvae or their silken feeding tubes which extend laterally in the soil from plant bases.