Abstract
In 81 tests in 21 localities, from 1952 to 1955, whole-field applications of DDT sprays against adults of root maggots attacking rutabagas, chiefly Hylemya brassicae (Bouché), generally gave 50 to 90 per cent fewer infested plants than in untreated fields nearby. The sprays, each at 1 lb of toxicant per acre, were applied at weekly intervals while flies emerged from overwintered puparia, the period varying with soil type. In eight plot experiments in 1955, a pre-planting treatment with heptachlor at 5 lb. per acre in a 5-inch band, [Formula: see text] inches below the seed in the planting ridge, gave an average of 93 per cent control; a similar treatment with aldrin, 80 per cent. Furrow applications at 5 and 2.5 lb. at the same depth were less effective. Post-thinning sprays applied to the crowns of the plants and surrounding soil surface were ineffective. None of the treatments was phytotoxic.
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call