Chlorophyll fluorescence as a rapid test for reaction to urea herbicides in winter wheat

Summary A simple and rapid test is described which can be used to determine tolerance to metoxuron and chlortoluron herbicides in winter wheat (Triticum aestivumL.) cultivars. Seedlings 5 days old were treated by root application of herbicide for 24 h and tolerant and susceptible cultivars were identified by comparing the chlorophyll fluorescence induction curves for both herbicide-treated and control plants after 7 days. The method was thus capable of detecting cultivar tolerance or susceptibility to the herbicides within 12 days of sowing the seed, providing a rapid and effective screening method. Possible uses for this new test are discussed.