Methyl Bromide and Steam Treatment of an Organic Soil for Control of Fusarium Yellows of Celery

Abstract

Fumigation of an orgamc soil naturally infested with Fusarium oxysporum f. sp. apii race 2 with a mixture of 98% methyl bromide and 2% chlqropicrin (0.15 kg a.i./ m2) eradicated the pathogen that causes Fusarium yellows of celery from both the soil and the celery root pieces in the soil. Celery seedlings and transplants grown for 12 and 5 wk, respectively, in the fumigated soil were dtsease-free. Pasteurization (70 C, 30 min) and autoclaving (121 C, 3 hr) of the soli also destroyed the pathogen and, in addition, greatly stimulated growth of cetery seedlings. In general, top growth of direct-seeded celery was not affected by duration of poststeaming sot! incubation When celery was transplanted into unincubated steamed soils,however, considerable injury occurred and top growth was significantly less than in soils incubated for 12, 24. or 36 days