Relations between the metabolism of the insecticide carbofuran in the soil and in the plant of cauliflower and Brussels sprouts crops made in the field

Abstract

The insecticide carbofuran was applied at planting onto soil around the stem of cauliflower and brussels sprouts plants of field crops made in different regions and seasons of culture. Carbofuran and its metabolites were measured several times in soil and plant growth. In the soil, carbofuran was metabolized into 3‐ketocarbofuran, 3‐hydroxycarbofuran, carbofuran phenol and 3‐ketocarbofuran phenol. The rate of carbofuran soil biodegradation was higher in the spring than in the summer, and when the history of the soil as to continuous cauliflower monoculture and insecticide tretments was greater. In the foliage of cauliflower and brussels sprouts plants, carbofuran, 3‐ketocarbofuran, and especially 3‐hydroxycarbofuran were observed; their concentrations in the plant foliage decreased progressively with plant growth; these concentrations, and the total weight of carbamate compounds in the foliage of one plant were greater when the soil concentrations were greater. The same factors (soil history as to cabbage...