A softer finish to this year’s winter crop could mask issues with crown rot across the Australian wheatbelt.
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 equals no inoculum, says Syngenta Seedcare technical specialist Sean Roberts.
“There’s now considerable research and understanding between experts in this field, that inoculum will in fact continue to build up in softer years,” he said.
“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.”
Mr Roberts said 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 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 the 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.”
Syngenta, a global leader in agricultural research and development, has observed the challenge this has presented in Australia. While the expression of this disease is mostly observed during plant maturity, Syngenta turned its attention to the early establishment phase when infection ordinarily happens.
In partnership with industry, Syngenta is supporting the implementation of integrated management strategies for crown rot, including provision of Predicta B soil testing kits.
Through this DNA identification of soil and stubble-borne crown rot, among other diseases, it believes farmers can reduce their risk and unnecessary yield losses.
Syngenta is also working toward the registration of Victrato seed treatment, an Australian-first for crown rot control and management of root lesion nematodes, to complement cultural control measures.
Syngenta is encouraging farmers and advisors to take a soil test for nematodes to guard against the risk to next season’s crops.
*Victrato is not a registered product. A registration application has been submitted to the APVMA.
