Pear, Agri-Mek Timing Study, Wenatchee 1991

Abstract

Abstract Eleven-yr-old 'Bartlett' and 'Anjou' pear trees were sprayed with an air carrier sprayer to compare effectiveness of petal fall and second-generation timing of Agri-Mek for control of pear psylla. Plots consisted of 2 replicates of 12 by 6 tree rectangles. Additional sprays applied to the entire orchard during the growing season included Guthion 35% WP 3 lb/acre on 17 Jul and Guthion 35% WP 2 lb plus Mitac 50% WP 3 lb/acre on 31 Jul. Treatments were evaluated for PP by counts made at 2-wk intervals. Adult PP were counted from a 25-beatingtray sample per replication. PP nymphs were counted from 2 50-leaf samples per replicate. Leaf samples consisted of the proximal leaf, distal leaf, and 3 leaves from the middle of 10 terminal shoots. Leaves were brushed and resulting slides were examined under magnification. PP russet was rated according to US grade standards for fresh market pears on 50 mature fruit per cultivar per replication. Factors of fruit quality including firmness, soluble solids, and size were evaluated from 2 10-fruit samples per replicate at normal harvest maturity. Fruit and foliage were examined for phytotoxicity after each spray.