Pear, Pear Psylla Control, 1986

Abstract

Abstract Five-year-old pear trees were sprayed with handguns operating at 600 psi to evaluate pesticides for control of PP. Plots consisted of unreplicated blocks 2 rows wide containing ca. 48 trees. In the standard program trees were sprayed as follows: 18 Mar—Pydrin 2.4 lb/gal EC .075 lb (AI)/100 gal plus superior oil 1 gal/100 gal; 7 Apr—Morestan 25% WP .25 lb (AI) plus Pydrin 2.4 EC .075 lb (AI) plus Parathion 4F .25 lb (AI)/100 gal; 28 May and 19 Jun—Guthion 50% WP .25 lb (AI)/100 gal; and 17 Jul— Mitac 50% WP .375 lb (AI) plus Guthion .25 lb (AI)/100 gal. The 3 insect growth regulators (IGR's) (first 3 treatments in tables) were applied 7 Apr, 30 Apr, 28 May, 19 Jun and 17 Jul. PP eggs, nymphs and adults were counted at 2-week intervals. Adults were counted on 25 limb taps/plot. Eggs and nymphs were counted on 2 samples of 5 fruiting spurs/plot from 8 Apr through 8 May and 2 50-leaf samples/plot thereafter. All spur tissues were examined under a dissecting microscope; leaf samples were processed using the standard leaf brushing technique. Adults were counted by the limb-tap method. Phytophagous mites were also counted on brushed-leaf samples. AA infestations were rated by determining percent infested terminals and average number of infested leaves/terminal by examining all terminals in plots. PP, PRM russets and CM damage were rated according to US grade standards for fresh market pears on 2 samples of 25 fruit/rep.