Insegar Rate Study, 1990

Abstract

Abstract Mature bearing 'Anjou' trees were sprayed with aircarrier equipment applying 400 gal/acre for control of pear pests. Three rates of Insegar were compared to a standard program including a 15 May application of Guthion 35% WP 3 lb, Agri-Mek . 15 E 20 oz and oil 1 gal/ acre followed by a 19 Jun application of Guthion 35% WP 3 lb/acre. Insegar was applied 4 times during the season beginning at first egg lay of codling moth as determined by DD accumulation and again 21 d later for first generation then 2 second brood sprays timed the same way. Application dates and corresponding DD post biofix were as follows: 23 Apr, 74; 15 May, 231; 19 Jun, 586 and 9 Jul, 993. Plots consisted of 3 replicates of 30-40 trees in rectangles. Treatments were evaluated for control of PP and phytophagous mite species by counts made at 2-wk intervals. Adults PP were counted from a 25-beating-tray sample per replication. PP nymphs and phytophagous mites were counted from a 50-leaf sample 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. Pest damage was rated according to U.S. grade standards for fresh market pears on 2 samples of 25 mature fruits 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.