STUDIES conducted in Victoria's Wimmera region have found the fungal disease septoria tritici blight (STB) will be increasingly problematic in medium rainfall zones in wet years such as last season.
Long regarded as a major problem in high rainfall zone environments, STB has been increasing as a problem into areas traditionally too dry for it to be an economically damaging problem.
This year, with conditions ideal following a wet spring, STB emerged as the second most damaging disease in wheat across the country, trailing only stripe rust, which caused severe yield damage following heavy infestations in the spring.
Hari Dadu, Agriculture Victoria field crop disease research scientist, said at Birchip Cropping Group's trial review day last Friday that STB had caused yield losses of up to 43 per cent in susceptible varieties in MRZs through the Wimmera last season.
However, the trials also found that with fungicide application yield in the susceptible varieties could be increased.
There was better news for low rainfall zone croppers.
Genevieve Clarke, BCG research and extension officer, said while there had been STB observed in LRZ trials it had not been present in yield or economically damaging levels.
Ms Clarke said last season, with its protracted wet spell through spring, where plants did not dry out for weeks on end, had been conducive to the spread of STB, with the disease able to progress to the top of the plants.
While pronounced last year, Dr Dadu warned that it was not the first time STB had been seen at economically damaging levels in the MRZ.
"The losses were not as severe in 2021 but the disease was definitely present."
Ms Clarke said a key defence for growers was choosing resistant varieties.
"The yield losses can be greatly reduced when growers choose resistance varieties," she said.
Dr Dadu said data had showed top end yield losses of 43pc at Longerenong in the Wimmera but this dropped to 21pc or lower in more resistant lines.
Another positive was the impact of fungicides, with all products used in the Longerenong trial reducing STB severity compared to the untreated plots.
Gregor Heard
Gregor Heard is ACM's national grains industry reporter, based in Horsham, Victoria. He has a wealth of knowledge surrounding the cropping sector through his 15 years in the role. Prior to that he was with the Fairfax network as a reporter with Stock & Land. Some of the major issues he has reported on during his time with the company include the deregulation of the export wheat market, the introduction of genetically modified crops and the fight to protect growers better from grain trader insolvencies. Still involved with the family farm he is passionate about rural Australia and its people and hopes to use his role to act as an advocate for those involved in the grain sector.
Gregor Heard is ACM's national grains industry reporter, based in Horsham, Victoria. He has a wealth of knowledge surrounding the cropping sector through his 15 years in the role. Prior to that he was with the Fairfax network as a reporter with Stock & Land. Some of the major issues he has reported on during his time with the company include the deregulation of the export wheat market, the introduction of genetically modified crops and the fight to protect growers better from grain trader insolvencies. Still involved with the family farm he is passionate about rural Australia and its people and hopes to use his role to act as an advocate for those involved in the grain sector.
