Pear, Prebloom Applications of Insegar for Control of Pear Psylla, 1991

Mature bearing pear trees were sprayed with air carrier equipment applying 400 gal per acre to test prebloom applications of Insegar for control of PP. Plots consisted of unreplicated blocks of 1/2 acre or larger. Treatments were applied at delayed dormant (20 Mar) and at clusterbud (8 Apr) stages of tree development. Additional sprays applied to the entire orchard during the growing season included Dimilin 25% WP 1 lb/acre plus superior type oil 1 gal/acre on May 31, Guthion 35% WP 2.5 lb/acre plus Vendex 4 L 2 pt/acre on 11 Jul and Guthion 35% WP 2 lb/acre plus Mitac 50% WP 3 lb/acre on 31 Jul. Treatments were evaluated by adult, egg, and nymph counts on several dates after treatment. Adults were counted by the limb tap method. Early season eggs and nymphs were counted on fruiting spurs collected at random from test plots and examined under magnification in the laboratory. Later egg and nymph samples were counted from 2 50-leaf samples per plot. 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 'Bartlett' and 'd'Anjou' pears on 2 samples of 25 mature fruit per plot. Factors of fruit quality including firmness, soluble solids, and size were evaluated from 2 10-fruit samples per plot at normal harvest maturity. Fruit and foliage were examined for phytotoxicity after each spray.