The year 2017 may very well be remembered as the year the rain just didn’t come. Across much of Canada, conditions as we near potato harvest are notably dry and hot. With the exception of cooler, wetter than normal conditions in certain areas of Ontario, much of the country has seen little rain since May and June. Unfortunately, dry conditions limit yield, challenge growers at harvest, and can increase the risk of disease in storage.
Most of our country was consistently warm this summer. Depending on variety and planting timing, the tuber set in certain fields may be impacted by the warm weather. However, moisture availability (or, more correctly, the lack thereof) will prove to be a much bigger factor in ultimate yield. Because potatoes are drought sensitive, many western Canadian and Maritime farmers growing potatoes on non-irrigated fields should expect at least somewhat reduced yield this harvest.
Pulling up dirt clods is virtually unavoidable when harvesting in dry ground. Unfortunately, the dirt clods, combined with lower tuber volume, result in a poor flow of potatoes up the primary digging chain. It is very difficult to mitigate the rolling, jarring and bruising of tubers when digging under less than ideal conditions.
Most bruising is not visible when tubers are in cool storage. Unfortunately, the invisible damage is an ideal harbour for pathogens. As Alberta growers who stored bruised product following the drought of 2002 will remember, those pathogens can result in disease losses come spring.
To reduce the potential for disease issues through the fall and winter, tubers harvested from dry ground should be treated with fungicide as they enter storage to help them heal wounds before secondary infections occur. Following suberization, growers should take samples at least two or three times during the storage period. Letting the tubers warm for several hours can paint a very different picture of your stored product reality.
Next spring, expect a higher grade out and, consequently, less seed available for sale. Open, clear communication between seed grower and buyer will be critical. We always preach that buyers should see seedlots prior to purchase. This year, that task should be mandatory. Be aware that many problems won’t show themselves until at least January, so plan a visit for February or even March to be on the extra-cautious side.
Seed producers will have to manage quality carefully. They should warm tubers prior to grading and shipping, both to accurately assess condition and to reduce further damage. Remember: it’s always better to keep problems at home rather than shipping them out to customers!