Pear, Agri-Mek Timing Study, Orondo, 1991

Abstract

Abstract Twenty-five-yr-old 'Bartlett' 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 half-acre unreplicated rectangles. The earlier treatment was applied 10 May, the later one 5 Jun. Additional sprays applied to the entire orchard during the growing season included Guthion 35% WP 2.5 lb/acre on 11 Jul and Guthion 35% WP 2 lb/acre plus Mitac 50% WP 3 lb/acre on 31 Jul. Treatments were evaluated for PP by counts made at 2-wk intervals. Adult samples consisted of 2 25-beating-tray samples per plot on each date. PP nymphs 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 and other pest damage were rated according to US grade standards for fresh market 'Bartlett' pears on 100 mature fruit per plot. Factors of fruit quality including firmness, soluble solids, and size were evaluated from 4 10-fruit samples per replicate at normal harvest maturity. Fruit and foliage were examined for phytotoxicity after each spray.