Experiments with Granulated Systemic Insecticides for Control of Insects on Potatoes, Lima Beans and Sweet Corn 1

Abstract

Granular formulations of the systemic insecticides phorate and Di-syston® ( O,O -diethyl S -2-(ethylthio)ethyl phosphorodithioate) banded beside the seed rows at planting time were effective against potato leafhoppers, Empoasca fabae (Harris); potato flea beetles, Epitrix cucumeris (Harris); and Colorado potato beetles, Leptinotarsa decemlineala (Say) on potatoes; the potato leafhopper and the Mexican bean beetle, Epilachna earirestis Mulsant, on lima beans and corn flea beetles, Chaetoc-nema pulicaria Melsh, on sweet corn. In general, yield increases of potatoes resulting from granulated Di-syston and phorate treatments were not so high as expected from the insect control achieved. Potatoes receiving foliar treatments of phosphamidon and Thiodan® (6,7,8,9,10,10-hexachloro-1,5,5a,6,9,9a-hexadro-,9-methano-2,4,9-benzodioxathiepin 3-oxide) consistently out yielded both the untreated and the traction-treated cheek plots, Yields of sweet corn from all granulated systemic insecticide and nematocide treatments were increased from 0.3 to 0.8 tons per acre although these increases were not significant at the 5% level.