Effect of Fruit Growth and Weather on Deposits of Insecticides on Apples in Southern Indiana

Abstract

Growth records of Grimes Golden apples for 4 consecutive yrs. and of several vars. of apples for 1 yr. showed that growth rate differed according to var. of fruit but only to a slight extent according to seasonal conditions. Fixed nicotine proved less susceptible to weathering than phenothiazine, and Pb arsenate was the least susceptible of the 3 insecticides. Fruit sprayed with Pb arsenate retained at harvest 51.5-76.1% of the total residue deposited during the season; fruit sprayed with fixed-nicotine retained 8.4-32.6% of the total residue, depending on the interval between the final cover spray and harvest and on the rainfall.