Broadcast Treatments for Control of the Cabbage Maggot in Radish, and Resultant Residues

In sandy loam soil at Ottawa, heptachlor and aldrin granules, broadcast at 3 lb. of toxicant per acre before planting, gave respectively 70 to 80 and 58 to 84 per cent control of a very severe infestation of the cabbage maggot in radish planted 0, 7, 15, and 21 days after treatment. Chlordane granules at 5 lb. gave 4 to 48 per cent control. The granulated insecticides were applied to the surface of the soil with a hand fertilizer spreader and raked into the top 2 inches. Insecticide residues on the radish roots at harvest were below the tolerances recently established in Canada for this crop.