Yield and injury effects on vegetable crops planted in flumetsulam-treatedsoil

The effect of flumetsulam on several vegetable crops grown following soybea n was investigated over a 4-yr period. Flumetsulam was applied preplant inc orporated to soybean at 0, 70 and 140 g a.i. ha(-1) from 1992 to 1994. In t rials 1 yr after flumetsulam application, cabbage (Brassica oleracea var. c apitata), potato (Solanum tuberosum L.), tomato (Lycopersicon esculentum L. ), and pepper (Capsicum annuum L.), showed visual injury symptoms and reduc ed yields in 1993, while only cabbage showed visual injury symptoms and red uced yields in 1994 and 1995. Cucumber (Cucumis sativus) showed injury symp toms only in 1993 and had no yield reduction. Cabbage also showed visual in jury and reduced yields 2 and 3 yr following a 1992 flumetsulam application . Broccoli (Brassica oleracea var. italica) and cauliflower (Brassica olera cea var. botrytis) showed visual injury symptoms in 1995, 3 yr after flumet sulam application Generally, crop tolerance decreased linearly as applicati on dose increased from 0 to 140 g ha(-1). Minor visual injury symptoms did not correspond with a reduced yield. Injury was most, severe on sites with the lowest soil pH values. Based on these studies, effects of flumetsulam f rom normal use rates (70 g ha(-1)) will carry over to injure-sensitive crop s like cabbage, in the rotation for up to 3 yr, especially in low pH soils (pH 6.1 or less). Otherwise, a 22-mo planting interval is adequate to prote ct other vegetable crops in the rotation from injury and yield reductions.