White rot alert

White rot alert

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Symptoms of white rot seen on a garlic plant – the disease manifests as a fluffy white growth on the plant roots and root plate, with tiny black growths like poppy seeds.

WA gardeners harvesting vegetables from the onion family (alliums) have been urged to report any signs of white rot to the Department of Agriculture and Food after it was found in a Perth backyard recently.

A Swan Valley gardener found the fungal disease in garlic.

It is the first time white rot has been found in WA to which garlic and onions are particularly susceptible as well as leeks, shallots, chives and ornamental alliums.

Department chief plant biosecurity officer John van Schagen said the cold, damp spring most likely provided suitable conditions for the white rot fungus to develop to a stage where it was visible to the naked eye.

He asked vegetable growers to inspect their plots and report any symptoms to help determine whether or not the disease was widespread.

“Often there are limited above-ground symptoms of white rot disease, such as stunted growth or yellowing and wilted leaves, and the disease is first discovered when harvested,” he said.

“The disease manifests as a fluffy white growth on the plant roots and root plate with tiny black growths like poppy seeds, which are called sclerotia.”

Mr van Schagen encouraged growers to employ good biosecurity measures to prevent the risk of spreading white rot.

“It is important for gardeners to wash any soil from infected parts of the garden off their footwear and tools before moving to other areas of the property,” he said.

“The best way to avoid infection is to purchase plants that are certified as disease free or grow crops from seed.”

While white rot in alliums is new to WA, the disease is widespread in the eastern states and overseas.

There are currently no white rot resistant varieties available however the disease can be managed by good sanitation, rotating plantings and use of registered fungicides.

For more information on control options visit agric.wa.gov.au/whiterot.

Any suspect signs of white rot can be reported to the department’s pest and disease information service on freecall 1800 084 881.

For further information email the department at info@agric.wa.gov.au.