Late blight has been reported last week from southern Pembina County, which is in the northeast of North Dakota and adjacent to south-eastern Manitoba and north-western Minnesota, Manitoba’s extension plant pathologist Vikram Bisht says in the weekly Potato News issued July 26.
With widespread rain July 23 and thunderstorm expected this week, there will be plenty of moisture in the crop canopy. “It is important to closely monitor for late blight in potential risk areas in fields with wind breaks and rolling topography with many low lying spots,” he said.
All weather stations in the western region of the province are close to or above the DSV threshold for late blight, a few stations in the central and southern potato areas are near or above the threshold.
With late blight reports coming from close-by areas, it is important to keep all crops covered with protectant fungicide, especially the new foliage and also with-in canopy foliage. As yet, no blight has been found in Manitoba.