Yield enhancement and insect suppression with chlordimeform (Fundal) on dryland cotton

Chlordimeform was evaluated in four large-plot field tests over 2 years to determine its effect on yield ehancement for a short-season, dryland cotton system under typical insect pest management. Four or seven applications of chlordimeform (0.14 kg (AI)/ha) were made at the sixth true leaf stage and reapplied at 5-day intervals. Densities of early season cotton fleahoppers, Pseudatomoscelis seriatus (Reuter), and blasted squares were reduced as much as 50% by multiple applications of chlordimeform. Fleahopper nymph densities were reduced 85%. Predaceous insects and spiders were not significantly affected. Chlordimeform increased early square and boll counts, earliness of harvest, and total bolls (12.2%) and lint harvested (6.4%) per ha, but had no measurable effect on lint per boll or boll diameter. Significant increases in yield and earliness of fruit set were attributed, in part, to reduced insect damage in the chlordimeform-treated plots.