Crops

Weed resistance warning

Gulshan Mahajan

A weed of Australia’s northern grain regions is displaying strong glyphosate resistance and could become a national headache, according to Queensland research.

QAAFI scientists are reporting stands of Echinochloa colona – also known as jungle rice, deccan grass, or Awnless barnyard grass – are not only showing high levels of resistance, but are producing high seed numbers.

Lead author Gulshan Mahajan explained there have been reports of poor control of E. colona using glyphosate in no-till farms in the northern grain region.

The researchers analysed 10 populations of E. colona to understand differences in their growth behaviour and resistance pattern. They studied plant growth as well as tiller, leaf and seed head production and glyphosate dose-response.

Dr Mahajan said: “Our results suggest that some populations of E. colona are highly problematic. There is a possibility of great risk with the increased use of glyphosate for managing E. colona in Australia’s northern grain regions. The results warrant integrated weed management strategies and improved stewardship guidelines are required for managing glyphosate-resistant populations of E. colona and to restrict further movement of resistant populations to other regions of Australia.”

Other researchers involved in the study were Vishavdeep Kaur, Michael Thompson and Bhagirath Singh Chauhan

Source: https://doi.org/10.1371/journal.pone.0221382