Pear, Effect of Calcium Chloride on Pear Psylla Control, 1987

A 4.4-acre 60-yr-old commercial pear block was subdivided into 4 equal-sized plots. Two plots were treated with calcium chloride (MORA-LEAF 94%) on 14 and 28 Jul and 12 Aug. Calcium chloride was tank-mixed with other materials, which were applied on those dates. Triton B-1956 was added as spreader at 2 oz/100 gal to all calcium chloride treatments except the first. The postbloom insect and mite control program consisted of the following (rates are given as formulated material/acre): Guthion 50WP (1.25 lb) on 19 May, 3 Jun, 28 Jul, and 12 Aug; Vydate L (2 qt) plus Plictran 50 WP (2 lb) on 3 Jun and 14 Jul; and Mitac (3 lb) on 28 Jul. Streptomycin and fungicides were applied as needed for disease control. PP nymphs and eggs were counted on 96 terminal leaves/replicate (1 leaf each from top, middle, and bottom position from 2 terminals/tree). Leaves were examined under a stereo microscope. In addition, 100 leaves/replicate (5 leaves each from 20 trees) were brushed with a mite-brushing machine to evaluate mite populations. Fruit of each variety was examined at harvest for PP russett (200 fruit/replicate).