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Downy mildew in Ontario onions

NEWS HIGHLIGHT

Downy mildew in Ontario onions

Reports of downy mildew in onions continue to come into Kristy Grigg,
vegetable specialist with the Ontario Ministry of Agriculture, Food and
Rural Affairs.

September 2, 2008, Ridgetown, Ont. – Reports of downy mildew in onions continue to come into Kristy Grigg, vegetable specialist with the Ontario Ministry of Agriculture, Food and Rural Affairs.

Infected fields have been confirmed throughout Southwestern Ontario, ranging from Chatham-Kent and Norfolk County to both the Thedford-Grand Bend and Bradford-Holland Marshes.

Growers are advised to watch for pale, elongated patches with grey/violet fuzzy growth, often affecting the older leaves first. Infected leaves wilt and may collapse. At this time of the year, downy mildew could potentially affect bulb yield and storage capacity.

Growers should be aware of their local DOWNCAST, if there is one available for their region. Otherwise, growers should follow a preventative spray program when frequent cooler, wet temperatures provide favourable conditions for disease development.

Producers should refer to OMAFRA Publication 363 or contact Kristy Grigg (kristy.grigg@ontario.ca) for more information and control options.