Filmcoating the seed of cabbage (Brassica oleracea L. convar. Capitata L.) and cauliflower (Brassica oleracea L. var. Botrytis L.) with imidacloprid and spinosad to control insect pests

Four field experiments were carried out between 1999 and 2001, to assess the protection against cabbage root fly larvae (Delia radicum), flea beetle (Phyllotreta nemorum and P. undulata), cabbage aphid (Brevicoryne brassicae) and caterpillars achieved in white cabbage and cauliflower crops by filmcoating the seed with insecticide. The plants were raised in trays of modules filled loosely with a peat-based potting compost. Batches of seed filmcoated with spinosad at five rates and imidacloprid at four rates, and also the combined products, were compared with a conventional post-planting treatment or with seed filmcoated with chlorpyrifos. Filmcoating with spinosad was ineffective at controlling flea beetle and cabbage aphid, whereas it gave a good control of cabbage root fly larvae and caterpillars at rates of 24 and 48 g a.i. per 100,000 seeds. Imidacloprid was ineffective at controlling cabbage root fly larvae and caterpillars whereas it gave a good control of flea beetle, and cabbage aphids at a rate of 70g a.i. per 100,000 seeds. Using high-quality seeds, there was no significant effect on the number of riable plants produced; however, imidacloprid reduced plant weight by 15% at the transplanting stage. The combined application of spinosad and imidacloprid as a filmcoating on seeds is an environmentally friendly alternative for protecting brassica crops against pests that occur frequently. (C) 2003 Elsevier Science Ltd. All rights reserved.