A new decision support tool has been developed to help growers manage the damaging fungal disease yellow leaf spot.
YellowSpotWM will help growers and advisors make more informed decision in managing the disease, which the Grains Research and Development Corporation rates as the single most economically damaging disease in wheat, causing up to $30 a hectare in lost production and extra costs in bad seasons.
The tool was developed as part of a three-year $3.5 million GRDC and Department of Primary Industries and Regional Development (DPIRD) in Western Australia research co-investment 'Disease epidemiology and management tools for Australian grain growers'.
Yellow leaf spot is caused by the fungus Pyrenophora tritici-repentis, and is a stubble-borne disease can infect all bread wheat, durum and triticale varieties causing yield loss and reduced grain quality.
DPIRD senior research scientist Jean Galloway said the YellowSpotWM tool was designed for use during the growing season and would assist grain growers and agronomists to make more informed decisions about fungicide application to optimise yield and minimise costs in individual paddocks.
"The tool is intuitive and straightforward to use and requires the user to input individual paddock data, as well as expected weather conditions," Ms Galloway said.
"It then uses a forecasting model to generate the predicted return from a fungicide treatment, in dollars per hectare, highlighting the probability of a negative or positive return," she said.
GRDC disease manager Friday Obanor, said the new tool would be an important weapon in the management arsenal for growers and advisers battling of one of the grains industry's most problematic diseases.
"Yellow leaf spot is a very significant disease for wheat growers, particularly in New South Wales, Western Australia and Victoria," Dr Obanor said.
"The disease has been known to cause up to 60 per cent yield losses in susceptible wheat varieties under conditions favourable for fungal development," he said.
"Successful management requires an integrated disease management approach including crop rotation, timely application of fungicides to protect the most important leaves, removal of stubble and selection of resistant wheat varieties."
However, Dr Obanor said research had shown that the timing of fungicide application was particularly crucial in minimising yield loss.
Research had also confirmed that yield and quality losses, as a result of yellow spot infection, were greater in more susceptible varieties than in varieties with some level of resistance to the pathogen.
"Consequently, it is important to consider the economic benefit of applying fungicide to a variety with good levels of resistance, unless disease pressure is very high and the environment is conducive to further disease development - in which case fungicides should definitely be applied," Dr Obanor said.