Chlortoluron levels and selectivity in wheat cultivars

Abstract Chlortoluron determination in seedlings of four wheat cultivars have been carried out by gas liquid chromatography with alkali flame-ionization detection. Recoveries through the method were always higher than 70% and the limit of detection was 0.01 ppm. Herbicide levels have been determined at different times after treatment. No significant differences among cultivars have been found in chlortoluron levels at the end of 24 h treatment, while six days after treatment susceptible cultivars showed levels of chlortoluron clearly higher than tolerant cultivars. A good correlation was observed between herbicide level and plant fresh weight in the studied cultivars six days after treatment.