The Echinochloa crus-galli complex in rice - morphological variants and tolerance to propanil in Greece.
Two morphological variants of E. crus-galli were found in rice fields in Greece, a rice mimic, probably E. crus-galli var. oryzicola and the more typical form, probably E. crus-galli var. crus-galli which was less frequently observed. E. crus-galli from rice was found to be more tolerant to propanil at 6 kg/ha than E. crus-galli from vegetables. Increased tolerance was observed in both variants and was not correlated to plant vigour but was associated with repeated use of propanil. Variations in tolerance to propanil were confirmed by measurement of electrolytic conductivity and provided a method for rapid detection of susceptibility or tolerance.