Pear, Evaluation of Dimilin For Pear Psylla Control, 1986

The trial was conducted in a 3 acre block of ‘Bartlett’ pears near Biglerville, PA. Six trees were randomly chosen in the block for monitoring. Three trees at the edge of the block were left untreated and served as controls. Chemicals were applied as a complete spray to both sides of trees with a Bean airblast sprayer calibrated to deliver 50 gal/acre. Application dates and rates were as follows: 1 Apr—bud burst (Dimilin 25WP 454 g plus 60 sec. oil 10.1 liters/acre), 14 Apr—white bud (Dimilin 25WP 454 g plus Manzate 200 1.2 Kg/acre). When PP populations on control trees reached damaging levels, they were treated with a handgun to the point of runoff. Application dates and rates for control trees were as follows: 9 May (Pydrin 2.4EC 118 ml plus Mitac 1.5EC 473ml/100 gals), and 23 May (Thiodan 50WP 454 g plus Mitac 1.5EC 946 ml/100 gals). Treatments were evaluated for PP control by counts of eggs and nymphs at 1 to 2 week intervals. Counts were made by sampling 10 spur or mid-terminal leaves per tree. PP pressure was heavy.