Greenhouse Whitefly Control on Potted Chrysanthemums, Massachusetts, 1981

Nine insecticides were tested for control of greenhouse whiteflies. Each material was applied with a 1 liter hand-sprayer to the upper and lower leaf surfaces of the plants. Four 15 cm pots, each containing chrysanthemums, were treated with each material and placed at random on a greenhouse bench. Applications were made at weekly (Enstar, methoprene) or bi-wekly (all others) intervals beginning Jun 12 and ending Jul 15. Buds had begun to form at the beginning of the test period, and began to break around Jul 20. Plants were evaluated at least twice a week through Jul 28 for relative severity of whitefly infestation and phytotoxic effects of the chemicals used.