Using leaf chlorophyll fluorescence for in-season diagnosing herbicide resistance in Echinochloa species at reproductive growth stage

Abstract

The chlorophyll fluorescence measurement to diagnose herbicide resistant Echinochloa species at the reproductive (late) growth stage was applied. The significant correlation between Fv/Fm (chlorophyll fluorescence measurements) and fresh weight (whole plant test) and the statistical similarity of R/S ratios between the two tests demonstrated that the chlorophyll fluorescence test could be reliably used to diagnose herbicide resistant Echinochloa spp. at the reproductive growth stage in a shorter period of time (within 10 days) compared with the conventional whole plant test.