The Tasmanian Institute of Agriculture (TIA) is conducting research trials to help onion growers better predict and control white rot disease.
The trials are measuring onion root growth, disease development and environmental conditions, including soil temperature, soil moisture and crop growth.
This information will be used to develop a risk prediction tool that will help growers better control the disease. For example, the information will help onion producers identify when disease is likely to be active in the soil so that fungicides can be applied during periods likely to provide the most effective control.
What is white rot?
Onion white rot is a destructive fungal disease that reduces the yield of commercial onion crops. This soil borne disease is caused by Sclerotium cepivorum and affects Allium species including garlic, leek, chives and spring onion.
The fungus infects plant roots and progresses up the roots to the base of the onion bulb. Infection can spread from the roots of one plant to another, resulting in patches of infected plants.
Early above-ground symptoms are white fluffy mould on the stem plate (the junction between the bulb and the roots) and on the lower part of the bulb near the soil surface.