Performance and Soil Persistence of Chlorsulfuron when Used for Wheat Production in Spain

Abstract

Chlorsulfuron was preemergence applied in field trials at La Coruña, Spain, at rates from 5 to 30 g ai ha−1(1987–88) and from 5 to 100 g ai ha−1(1988–89) for weed control in winter and spring wheat. Excellent control of broadleaf weeds was obtained in both; however, narrowleaf control at the last evaluation (heading) was poor. Chlorsulfuron at 30 g ha−1did not cause a residual problem in 1987–88, with only 0.24 μg kg−1of dry soil recovered after both a winter and spring wheat cropping season. However, chlorsulfuron persistence at the same rate was very high in the dry year 1988–89, with 0.43 μg kg−1and 0.53 μg kg−1recovered in winter and spring wheat, respectively. ‘Cardeno’ spring wheat showed no phytotoxic symptom at any rate of chlorsulfuron from 5 to 100 g ha−1. Its yield and yield components (spikes m−2, grain number spike−1, grain weight) were greater with all chlorsulfuron rates, but not in ‘Fiel’ winter wheat for rates of 30 g ha−1or higher.