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Ontario Crop Production Update Oct. 11

Sunny, balmy weather this week allowed growers to make lots of progress with the harvest.  Many growers have finished digging. According to Mark VanOostrum, 80 per cent of the chipping crop has been dug.  The size profile is better than expected, and the quality is very good.  Rainfall was below average in June, July and August in the Alliston area, which resulted in poor crops in non-irrigated fields. I visited P &…

Driving Out Blight With Dual Control

Combining methods of disease control rather than relying on a single resistance strategy can extend the durability of crops by many years, confirms computer modelling that draws on classical population genetics theory. The finding comes from assessing the spread and virulence of the pathogen responsible for late blight of potato, Phytophthora infestans. The pathogen, which caused the Great Irish Famine in the mid-nineteenth century and led to the new science of plant…

Better Sooner Than Later

Late blight is a deadly disease that requires integrated management, including foliar fungicides as a key tool. Usually potato growers make repeated preventive applications of broad-spectrum fungicides starting before row closure, and then use late blight-specific fungicides if the disease is found in their fields. Now studies in Ontario and the Maritimes are working on easy-to-use technologies for early detection of late blight that could allow more targeted fungicide strategies. Late blight…

Harvest and Storage of Potato Crops Exposed to High Moisture Levels

Frequent and excessive rain received during the growing season is potentially conducive, especially in low spots and/or in poorly drained areas, to the development of some diseases, such as pink rot and Pythium leak (water rots). Growers with potato crops exposed to high moisture levels should follow the management practices below. Top kill at least two weeks prior to harvest to allow time for infected tubers to rot and to promote tuber…

Ontario Potato Production Update—September 9, 2019

According to Mark Van Oostrum, a few growers will start digging the storage crop this week, but the majority will start next week on September 16.  All the best for the storage crop harvest! Pink eye and road-mapping are both physiological problems that have been detected recently in a few fields. The photo above shows what pink eye looks like on tubers when freshly dug; the lesions will dry up and turn…

End-of-season checklist for managing late blight in Alberta

“Both industry and the public have increased awareness efforts with the intent of returning Alberta to late blight-free status,” explains Robert Spencer, commercial horticulture specialist at the Alberta Ag-Info Centre. “No cases of late blight have been reported as the 2019 growing season wraps up, despite favourable conditions for the disease in some parts of Alberta and some spores caught in monitoring traps.” He recommends that commercial or home garden potato or…

Ontario Potato Production Update: Sept. 3, 2019

Harvesting fresh market and field fry potatoes continued over the long weekend.  Quality of both are very good, but yields are variable depending on the field. The storage crop is being top-killed according to the planting date. The spore traps keep detecting DNA of late blight in Dufferin, Simcoe and Norfolk Counties. This is a very important alert for growers in Dufferin County where there are still fields that will need at…

Late Blight Found in Southwestern Ontario

Over the weekend, a Norfolk County grower found a few Envol plants infected with late blight. The disease is under control; the affected plants were destroyed and the field sprayed with Ridomil plus Bravo. Most of the reports of late blight from the United States have been US 23, the tomato strain.  US 23 is, so far, sensitive to Ridomil. There are still many fields in the province that are green and…

Is the Late Blight Pathogen Adapting to Weather Changes?

The breaking news last week was the detection of late blight on August 19 in six fields located in Minidoka County in Southern Idaho.  The weather there is dry; the average monthly rainfall is 0.7 inches from April to September. Potatoes are grown under irrigation, and after irrigation the canopy does not remain wet for very long.  This sort of weather is not favorable for late blight, so it came as a…

Ontario Crop Production Report: August 20, 2019

Finally, the Alliston, Ont., area that was hit hard by the summer drought received a much-needed rain over the weekend.  Mark VanOostrum had the details: North of Alliston 0.5 inches Alliston to Beeton 0.7 to 1.0 inches Shelburne to Orangeville 0.8 to 1.2 inches South 401 spud lane 2 to 3 inches The rain will take the pressure off irrigation for a few days and should help bulking the chip processing crop….

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