Current levels of herbicide resistance in broadacre farming across southern Australia

摘要

High levels of herbicide resistance in broadacre farming across southern Australia have been detected due to greater reliance on herbicides for weed control. Random seed surveys have detected alarming levels of herbicide resistance mLolium rigidum Gau-din (ryegrass) to Group A and B herbicides (Table 1). In contrast, lower levels of resistance to trifluralin have been detected in Victoria than in South Australia, the main reason being due to the higher selection pressure with this herbicide on ryegrass. In Avena spp. (wild oats), lower, but important levels of resistance to Group A herbicides have been detected (Table 1). The reduced distribution, lower initial frequency of resistance and the selfing nature of wild oats compared to ryegrass has contributed to a lower level of resistance to the former species (Table 1).