|K-State Research and Extension Horticulture Newsletter
A spreader-sticker should be used in fruit tree sprays to improve the distribution and retention of fungicides and insecticides on fruit and leaves. However, even with a spreader-sticker, a rain can reduce the length of time the materials are effective. Less than one inch of rain since the last spray will not significantly affect residues. One to two inches of rain will reduce the residue by one half. Reduce the number of days until the next spray by one half. More than two inches of rain since the last spray will remove most of the spray residue. Re-spray as soon as possible. (Ward Upham)
Ward Upham runs the Horticulture Response Center in the Department of Horticulture and Natural Resources at Kansas State University. Other contributors include K-State Extension Specialists.