Cotton growers are set to benefit from new research informing integrated weed management (IWM) strategies to better manage awnless barnyard grass.
Results from NSW Department of Primary Industries (DPI) and Cotton Research and Development Corporation research will be used to manage glyphosate-resistant weeds and help maintain glyphosate in cotton production systems.
NSW DPI researcher, Md Asaduzzaman, said research suggests that when glyphosate is absent, glyphosate-resistant awnless barnyard grass weeds (Echinochloa colona) won’t be as fit as susceptible weeds in the same paddock.
“But when glyphosate is used, the glyphosate-resistant plants may eventually dominate the field, favouring the selection of resistant plants over those which have not developed resistance,” Dr Asaduzzaman said.
“Glyphosate is an important herbicide in Australian agricultural production systems and new management practices are needed in cotton IWM systems.”
NSW DPI research agronomist and CottonInfo weeds technical lead, Eric Koetz, said the Australian cotton industry’s Herbicide Resistance Management Strategy (HRMS) aims to prolong the life of glyphosate in Roundup Ready® cotton production.
“The HRMS allows the use of glyphosate in combination with other tools to effectively disrupt targeted weeds and the IWM approach helps maintain finite herbicide resources,” Mr Koetz said.
“Soil-applied herbicide is one of the chemical options which target seedlings before they germinate early in the season, providing ongoing residual control and taking the pressure off glyphosate use.
“Other agronomic options, including cover crops and strategic tillage, enhance control of awnless barnyard grass.”
Researchers said measuring the fate of weeds populations, helped predict the number of resistant and susceptible plants under various conditions, particularly from high-selection herbicide pressure.
Survival and reproduction rates in resistant populations after herbicide exposure provide an accurate ecological measure of resistance.
These measurements provide vital information about the dynamics of resistant weed populations, which can be used to inform effective weed management strategies.
The research was published in Scientific Reports,” Fate and adaptive plasticity of heterogeneous resistant population of Echinochloa colona in response to glyphosate”, https://www.nature.com/articles/s41598-021-94370-7