Reduced Dosage of Methyl Bromide for Controlling Verticillium Wilt of Potato in Experimental and Commercial Plots.

The use of gas-impermeable films to reduce the dosage of methyl bromide (MB) required to control Verticillium wilt in potatoes was examined in field experiments, conducted in soils naturally infested with Verticillium dahliae. The incidence and severity of Verticillium wilt were significantly reduced (by 74 to 94%) by fumigation with MB at 50 g/m under standard low density polyethylene (LDPE) or at 25 g/m under gas-impermeable films. Fumigation at 25 g/m under LDPE was less effective.