Peach, San Jose Scale Control, 1978

Lorsban (chlorpyrifos) which is registered for control of peachtree borer, Synanthedonexitiosa (Say), and is known to be effective against climbing cutworms (I and A Tests 1978) was tested for control of San Jose scale. The plots consisted of two 30-tree rows/treatment and were located in an abandoned orchard heavily infested with scale. Two applications at 3 rates were tested. The first application on Apr 25 (calyx red or delayed dormant stagelwas a Lorsban + oil combination, but the second on Jul 10 was Lorsban only. The applications were made with a hand gun, using a Bean® piston pump sprayer at a pump pressure of 500 psi. Each tree was sprayed to the drip stage, which required 0.4 to 1.0 gal of spray/tree. The efficacy of the first treatment was determined by holding one 80-cm-long infested twig from each tree in a petri dish in the laboratory where the male scale emerged, and that of the combined treatments was determined by examining 10 fruit/tree at harvest for the presence of scale.