Prof Chauhan explains the trial on site to growers and agronomists. Photo: QAAFI

NEW SITES for field trials of a University of Queensland strategy to combat Phalaris are needed in southern Queensland and northern New South Wales.

Early trials in wheat and chickpea crops funded by the Grains Research and Development Corporation tested an integrated management system for the problematic winter grass weed, and it had shown promise.

UQ researcher Bhagirath Chauhan from the Queensland Alliance for Agriculture and Food Innovation said Phalaris was becoming more prevalent and its impact was growing.

“Phalaris has evolved resistance to commonly used herbicides in some places, so the aim of our work is to provide growers with some good options to help control it,” Professor Chauhan said.

Prof Chauhan with a phalaris plant setting seed.

Trials in wheat and chickpea were conducted at Gatton and Moonie in Qld, and Gurley for wheat and Garah for chickpea in NSW.

“We had success with a combination of chemical and non-chemical approaches in the trials.

“The results show that crop competition could be a good tool in the toolbox for producers dealing with Phalaris.

“That means increasing the seed rate of the crop; for chickpeas we could increase planting from 30 to 45 seeds per square metre, and in wheat from 100 seeds to 150.

“The aim is to achieve faster canopy closure to discourage the weed without losing crop yield.

“Of course, we still need sustainably used herbicides as well, but this strategy would ensure our existing herbicides remain effective for longer, slowing the weeds’ ability to become resistant.

“Often the idea is to hit a weed hard but if the herbicide doesn’t work, then crop competition can help suppress it by discouraging growth and seed production.”

The trial results were presented to growers and agronomists at the GRDC Grains Research Update in Goondiwindi early this month.

Prof Chauhan said the next step was further trials and to recruit a PhD candidate at UQ to conduct further studies into the biology and management of Phalaris.

“Any growers who have a problem with this weed and who are happy to host trials should get in touch with me.”

“The UQ weeds team will handle the entire trial, including planting, harvesting, spraying and cleaning.”

Prof Chauhan an be emailed at [email protected]

Source: The University of Queensland