Tolerance of wheat cultivars to metribuzin and implications for the control of Bromus diandrus and B. rigidus in Western Australia

Abstract

Field experiments were carried out in Western Australia to investigate the response of 9 wheat cultivars to metribuzin and to evaluate its potential for the control of Bromus diandrus and B. rigidus in wheat. The wheat cultivars differed significantly in their response to metribuzin; a South Australian cultivar (Blade) was markedly more tolerant than all other cultivars investigated. Metribuzin alone (100-150 g/ha) or as a tank-mix with pendimethalin, incorporated by sowing, combined reliable brome grass control with good crop safety when used on Blade. Post-emergence application of metribuzin was generally less effective on brome grass and more phytotoxic to the crop than incorporation by sowing. This herbicide-cultivar package gives farmers an opportunity to selectively control brome grass in wheat.