METSULFURON USE IN BARLEY AND RESIDUAL EFFECT ON SUCCEEDING CROPS

Abstract

Experiments conducted over 4 yr (1982–1985) determined the efficacy of metsulfuron for use in spring barley (Hordeum vulgare L. ’Volla’) and effects of herbicide residues on crops grown the next season. Barley tolerated metsulfuron at rates up to 72 g a.i. ha−1 with no significant effects on yield but 1000-kernel weight was significantly reduced in two of the three barley crops grown. Control of lamb’s-quarters (Chenopodium album L.) and low cudweed (Gnaphalium uliginosum L.) was acceptable and that of corn spurry (Spergula arvensis L.) and shepherd’s-purse (Capsella bursa-pastoris (L.) Medic.) better than the standard MCPA amine treatment. There was no significant effect on marketable and total yield of rutabaga (Brassica napobrassica Mill.) or potato (Solanum tuberosum L.) and none on total yield of silage corn (Zea mays L.) when each was grown the season after metsulfuron use. Reductions in corn root growth were noted in bioassay tests as late as 120 d after metsulfuron application but the lack of effects on yields of succeeding crops would indicate that the remaining residues were broken down or diluted by plowing and working the soil.Key words: Metsulfuron, barley, potato, rutabaga, silage corn, persistence