FILMCOATING OF CAULIFLOWER SEED (BRASSICA-OLERACEA L VAR BOTRYTIS L) WITH INSECTICIDES TO CONTROL THE CABBAGE ROOT FLY (DELIA-RADICUM)

To assess the protection against cabbage root fly larvae achieved in c auliflower crops by filmcoating the seed with insecticide, six field e xperiments were carried out between 1990 and 1991. Various dosages of insecticides were tested at four widely separated locations in The Net herlands with high and moderate population densities of the cabbage ro ot fly. The plants were raised in 'loose-filled cells' and peat 'block s', or as peg plants. The efficacy of formulations of isofenphos, chlo rpyrifos and fonofos, at two and three dosages of seed filmcoating, we re compared with a conventional post-planting treatment. Filmcoating w ith fonofos was less effective in controlling cabbage root fly larvae than the post-planting treatment. Chlorpyrifos at 28.8 g a.i. kg(-1) s eed and isofenphos at 30 g a.i. kg(-1) seed consistently gave as good control as a post-planting treatment of each plant.