Effect of Foliar Fertilizer (22% Urea) on Aphid Control Test-Ii, 1990

Abstract

Abstract The experimental design was a randomized complete block, with 5 treatments and a control replicated 5 times. Cotton was planted on 26 Apr with plots consisting of 6 rows (40 in) × 50 ft and foliar sprays were applied with a hi-clearance utility tractor equipped with a compressed air delivery system. Treatments were applied on 25 Jul and evaluations were made on 27 Jul and 1 Aug. The plots had not been treated previously and plant height at treatment initiation ranged from 30-48 inches. Effectiveness on aphid populations was evaluated by randomly collecting 20 plant terminals from the center 2 rows of each plot and placing them immediately into 0.95 liter glass jars. In the laboratory, 10 ml of sodium hypochlorite (5.25%), 5 ml of dilute liquid detergent solution, and 500 ml of tap water were added to the glass jars. Following vigorous agitation, the contents of the jars were poured onto a no. 30 metal sieve and plants were thoroughly washed to dislodge remaining aphids, which were funneled into 300-mesh sieves. Contents of the 300-mesh sieve were backwashed into a Buchner filter apparatus (7 cm diam) containing ruled filter paper. Numbers of aphids were determined using a Zeiss binocular stereoscope at 12 × magnification. No rainfall was recorded between 25 and 27 Jul and 0.5 in. of rain was recorded on 31 Jul.