Evaluation of Granular Insecticides Against Aphids on Chrysanthemum, 1993

Phytotoxicity and efficacy trials were conducted from 29 Sep through 6 Nov 1993 on potted chrysanthemums at a commercial chrysanthemum farm in Hilo, HI. Cuttings (2.5 inch) were planted in 6 inch plastic pots containing a 3: 1:1 mixture of peat, vermiculite and perlite and maintained by standard commercial growing practices. Treatments consisted of 4 replicates (1 pot per replicate, 3 plants per pot) arranged randomly on a bench in a fiberglass greenhouse. Insecticide granules were applied once 21 days after planting and immediately watered after treatment. Phytotoxicity was evaluated at: NTN 2.5G, 0.03 g (AI)/pot, 0.06 g (AI)/pot, 0.12 g (AI)/pot, Temik 10G, 0.045 g (AI)/pot. Both efficacy and phytotoxicity trials included an untreated control. For evaluation of efficacy, data on the number of aphids per terminal (bud and first three leaves) were taken weekly beginning 14 Oct through 6 Nov. Plants were observed for phytotoxicity weekly.