A NATIONAL network of trials over five years has resulted in a new online tool which helps growers to measure the potential impact of disease on yield.
The Yield Response Curves project was a national collaboration initiated by the Grains Research and Development Corporation (GRDC) to deliver quantitative information on wheat and barley variety yield response to disease, as mediated by variety resistance.
The five years worth of trials and experiments led to the development of yield response curves that incorporate a number of plant diseases and soil borne pathogens in order to measure their impact on yield in some of the more established cereal varieties.
Speaking on the GRDC Podcast, retired DPIRD principal research officer Robert Loughman said the project arose out of a desire to have a clearer understanding as to how growers use variety resistance information when they're making decisions about their cropping programs.
"There are a number of choices around varieties - yield is very important but some factors around proneness to disease can be critical in certain environments," Dr Loughman said.
"The project was really designed to fill in some knowledge gaps around that and to explore the extent to which varieties could underpin lower risk production in the presence of a range of disease threats that growers face around Australia every year."
Each of the trials over the five years were set up to derive statistically valid yield response curves to ensure the reliability of the information by creating a range of disease burdens in varieties that themselves had a range of resistance and tolerance to the disease.
A yield response curve is a function that describes two variables, yield and increasing pathogen burden.
It reports the relationship between those two variables and shows, for each variety, how much yield is lost as the disease burden increases.
Dr Loughman said growers were very familiar with using yield response curves in a number of areas.
"For example, in crop nutrition they're used to the fact that as you add additional nitrogen or nutrients, then you don't necessarily get the same level of yield addition," he said.
"In a similar way, we can derive quite clear value in terms of understanding some of the relationships between how much of a disease burden is occurring on a crop and their likely performance in onfarm situations."
That understanding was achieved by creating trials and experiments with some contrast and subtleties that probed different environments around Australia, different levels of disease intensity and different diseases.
"We've done that by combining different levels of intensity of those with different varieties having some or no resistance," Dr Loughman said.
"The interaction and expression of those factors is what's given us some really valuable information to understand how different varieties respond to diseases in different situations."
Throughout the five years, researchers focused on a range of foliar diseases, such as yellow spot, but also root disease, such as crown root, as well as root pests, such a root lesion nematode.
Currently the online tool is only available for wheat and a prototype can be accessed by heading to agric.wa.gov.au/grains/prototype- yield-loss-disease-model-online-tool
