Control of Whitefly in Cotton with Danitol, Asana, Monitor, Orthene and Combinations, 1992

Abstract

Abstract Twomonth old cotton plants grown in Sunshine Mix® potting mixture in 15 cm pots and exposed to heavy whitefly infestations were transferred on 1 May into spray booths (60 cm × 60 cm × 90 cm frames covered with polyethylene on three sides) arranged in a randomized complete block design with eight treatments and six replicates. Plants were irrigated daily using drip tubes to avoid wetting of foliage. Adult SW were counted on the third expanded leaf node from the growing point and nymphs were counted on a 2.1 cm diameter leaf disk from the leaf on the 5-6 node. A pre-treatment count of whitefly was made 48 h before the first spray. Whitefly adults were counted at 24 and 72 hours after each treatment on 6 May and 16 May (with exception to 17 May). Immatures were counted at 72 and 144 hours after each treatment. Plants were treated by spraying to runoff (concentration based on 568 liters/ha spray volume, ca. 5 ml/plant) using a CO2 backpack sprayer with two TX-2 hollow cone spray tips (Spraying Systems Co.) positioned 5 to 10 cm from the plant canopy (one above and one below) at 4.2 kg/cm2. The treatments on 6 May and 16 May were: 1) fenpropathrin (Danitol® 2.4 EC) 0.20 lb Al/acre, 2) methamidophos (Monitor® 4 EC) 0.75 lb Al/acre, 3) acephate (Orthene® 90 S) 1.00 lb Al/acre, 4) fenpropathrin + methamidophos, 5) fenpropathrin + acephate, 6) esfenvalerate (Asana® XL) 0.04 lb Al/acre + methamidophos, 7) esfenvalerate + acephate, and 8) an untreated check.