Post-harvest soil and stubble test key to managing disease risk
With winter grain harvesting completed now’s the perfect time to eliminate any guesswork with paddock plans and determine your crown rot risk ahead of wheat, durum and barley sowing.
While it’s widely understood tight finishes are more conducive to the expression of crown rot, many are still operating under the assumption that no symptoms means no inoculum when the opposite can be true in many paddocks.
“There’s considerable research now, and understanding between experts in this field, that inoculum will in fact continue to build up in softer years,” said Sean Roberts, Syngenta Technical Manager - Seedcare™ (pictured above).
“It’s never been more important to employ all available management methods, from soil and stubble testing, to crop rotation, variety selection and inter-row sowing.”
Stubble is the key to the challenge, with modern farming methods benefiting hugely from several associated benefits including soil water conservation, erosion control and improvements to soil structure.
However, the retention of this stubble has caused inoculum levels to build in many areas, as the disease survives as a cottonwool-like growth inside the stubble, causing subsequent infection of new crops.
Dr Steven Simpfendorfer is a specialist in the field with the NSW Department of Primary Industries.
“Conservation cropping has large system benefits but means that the stubble-borne pathogen, which causes Fusarium crown rot, is going to be in paddocks,” he said.
“What we push hard is not to despair – burning stubble and aggressive management strategies such as cultivation can potentially have worse impacts overall.”
South Australian-based Elders Tech Services Manager Lyndon May said recognising symptoms was important but not the complete picture.
“Yield losses of 20-40 percent in bread wheat due to crown rot are not uncommon, even when we’re not seeing white heads, yield loss is occurring,” he said.
“In our trial work, we’ve seen yield losses of 10-20 percent, where the only crown rot symptom was browning of stem bases.
“That’s a challenge we face with growers - there can be a significant yield penalty, but they may not recognise there’s a problem unless you see the common signs of white heads.”
Syngenta, a global leader in agricultural research and development, has observed the challenge this has presented in Australia.
While the impact of this disease is mostly observed during plant maturity, Syngenta turned its attention to the early establishment phase when infection ordinarily begins.
Mr Roberts has analysed the data from 300-plus crown rot trials across Australia in the process of seeking registration for VICTRATO® seed treatment, offering unparalleled protection from crown rot. These trials produced a significant yield improvement across barley, wheat and durum.
Mr Roberts said VICTRATO® seed treatment should be used as part of a comprehensive disease management strategy built upon testing and understanding of risk.
“PREDICTA* B analysis provides vital information to assess the risk of yield loss when deciding whether VICTRATO® seed treatment is needed,” he said.
To understand your crown rot risk, speak to your local Syngenta representative about a soil test for your paddocks today.
ENDS
About Syngenta Australia
Syngenta is a leading agriculture company helping to improve global food security by enabling millions of farmers to make better use of available resources. Through world class science and innovative crop solutions, our 28,000 people in over 90 countries are working to transform how crops are grown. We are committed to drive positive change in agriculture and embed sustainability across all aspects of our business.
