Pear: Pest Control, 1984

Abstract

Abstract Twenty-one year-old pear trees were sprayed with handguns operating at 600 psi to evaluate pesticides for control of pear pests. Plots consisted of five 2-tree replicates in randomized block design. Plots 1 and 2 were sprayed 4 May, 22 Jun and 11 Jul, plot 3 was sprayed 26 Apr, 13 Jun and 11 Jul and plots 4-9 were sprayed 4 May, 13 Jun and 11 Jul. Treatments were evaluated for pear psylla control by counts of adults and nymphs at 2-week intervals. Adults were counted from a 5 beating-tray sample/rep. Nymphs were counted from 50-leaf samples/rep. First generation nymph samples, those prior to 26 Jun, consisted of fruiting spur leaves. Later samples included the proximal, distal and 3 leaves from between, on each of 10 shoots/rep. Leaves were brushed and the resulting slides were examined using a dissecting microscope. Two 10-fruit samples/rep collected at normal harvest time were weighed and tested for firmness with a penetrometer. Soluble solids were measured with a refractometer on samples of the combined juice of each lot of 10 fruit. Pear psylla and pear rust mite russets were rated according to US grade standards for fresh market Bartlett pears on 2 samples of 25 fruit/rep. Fruit and foliage were examined after each spray date for phytotoxicity.