Problem weed evolves to grow in Queensland’s summer

Professor Bhagirath Chauhan says annual ryegrass in now germinating in temperatures as high as 40 degrees. Image: Megan Pope An introduced weed that already costs Australian grain growers more than $90 million a year is becoming an even bigger threat according to University of Queensland-led research. Professor Bhagirath Chauhan from the Queensland Alliance for Agriculture and Food Innovation (QAAFI) has found for the first time that annual ryegrass is now germinating in summer in northern grain growing regions. "This adaption is a potential disaster that could cost many millions of dollars across all cropping systems," Professor Chauhan said. "Annual ryegrass has mainly been a winter weed in the southern and western regions of Australia, but recently we have seen it in Queensland. "Not only is it germinating outside of the original winter window, but it is doing so in temperatures as high as 40 degrees and then growing to produce seeds in summer." Professor Chauhan said annual ryegrass can spread quickly, often carried accidentally by vehicles or, in one case, by a hale bale which fell from a truck. "Annual ryegrass can quickly spread from the roadside into a paddock and then grow alongside a crop," he said.