Greenhouse Whitefly Control on Marigolds, 1992

Abstract

Marigold plants were grown from seed in 6 inch clay pots for ten weeks (10 inches-12 inches tall) in a research greenhouse infested with whitefly at Michigan State University. The plants were watered by a drip irrigation system for 4 min each day, 3 d per wk (Mon, Wed, and Fri). Each treatment was replicated 6 times. Precounts were made from 5 leaves per plant on 21 Jul. Insecticides were applied with an R&D C02 sprayer with a single 8008 nozzle at 50 psi until runoff. Whitefly larvae and pupae on the undersides of leaves were counted on 12 Aug by sampling 5 leaves per plant.