Department of Agriculture and Food research officer Ravjit Khangura said sclerotinia cost WA canola growers $59 million in yield losses last year alone, where infection rates averaged 28 per cent of plants among 86 crops surveyed.
She said climate conditions created a ‘perfect storm’ for sclerotinia across the State.
‘Wet and humid conditions allowed a build-up of inoculum, resulting in a spore release at flowering time, which is why the disease was more aggressive than previous years,’ she said.
Dr Khangura said while the dry summer would have no impact on the disease prevalence this season, she urged growers to budget for extra fungicide.
The department is also developing a new forecasting system using epidemiological data collected over the past four years, for predicting the risk of sclerotinia stem rot. This would help growers in decision making on fungicide sprays.