ABSTRACT
Weeds are a persistent problem in agriculture, increasing production costs but reducing crop yields (Wu 2016). Worldwide, yield losses of approximately 34% are caused by crop weeds in broadacre crops and are higher than the losses caused by other crop pests (Jabran et al. 2015). Herbicides are the most widely used method to manage weeds in commercial crops. To date, weeds have globally evolved resistance to 23 of the 26 known herbicide sites of action and to 161 different herbicides (Heap 2017). Herbicide resistance in weeds restricts control options, thereby escalating economic loss and threatening agricultural sustainability (Wu 2016). This threat comes at a time when increasing global populations require greater agricultural productivity, and environmental concerns have resulted in significant restrictions on use of some herbicides.
