Aug 21, 2012 - Disease Report #23
By Dr. Vikram Bisht, Plant Pathologist, Potato & Horticultural Crops, Manitoba Agriculture, Foods & Rural Initiatives
New infections of late blight are being reported, a few kilometers from the confirmed case that was found last week in the RM of North Cypress. I am following up to confirm this new report.
Parts of fields at greater risk of late blight, including those close to tree lines, valleys, or otherwise wind-protected areas where the foliage tends to remain wet longer after rains, irrigation or overnight dew, should be scouted rigorously. Growers in the region are advised to tighten spray schedules and include translaminar–systemic fungicides along with contact protectant fungicides. In some cases it may be appropriate to apply fungicides by ground rigs in areas close to trees or under power-lines.
The late blight risk model has 7-day DSVs accumulation, which puts the risk at medium in western and central parts of the province. Forecast of warm and dry conditions this week should be helpful.
Being a community disease, it is important to share information on new finds of late blight as soon as possible so that growers in the area can take the necessary precautions to protect their fields.