Resistance to acetolactate synthase-inhibiting herbicides in Diplotaxis tenuifolia (L.) DC.

摘要

Diplotaxis tenuifolia (L.) DC. is a perennial weed that can be a particularly problematic weed of crops in certain areas of South Australia. In 2003, failure of sulfonylurea herbicides to control D. tenuifolia was reported from a number of sites across a substantial area near Streaky Bay in South Australia. Seed was collected and tested for resistance to chlorsulfuron and triasulfuron. Chlorsulfuron was applied post emergent at 15 g a.i. ha~(-1) when seedlings were at the two to four true leaf stage.A second application was made 28 days later. Triasulfuron at 22.5 g a.i. ha~(-1) was applied pre-emergent to soil into which D. tenuifolia seed had been sown. Of the 28 samples tested, 16 proved resistant to chlorsulfuron. The same populations were alsoresistant to triasulfuron. There was a degree of variation in the responses of the different populations to these herbicides suggesting that resistance had evolved more than once. Subsequent dose response experiments confirmed resistance to triasulfuronin one population. An unusual aspect of the evolution of resistance in D. tenuifolia is that it has occurred in a perennial species.