CROP MANAGEMENT Set the stage for a successful growing season. PREPPING POTATOES FOR PLANTING he practices used in selecting and preparing seed potatoes for planting play a big role in getting your crop off to a great beginning. “Testing for potato virus Y (PVY) should show the infection level is less than four per cent. Also, if the seed was produced in jurisdictions where Dickeya dianthicola – the new blackleg disease – was a problem the year before, growers should request a test for this emerging, destructive bacterial disease.” As well, Banks advises growers to avoid physiologically old seed. The physiological age of a seed lot depends not only on its chronological age but also on the environmental and management conditions that it has undergone. Physiological age increases with things like growing season stresses, warm storage temperatures, wounding, bruising and cutting. Knowing a seed lot’s physiological age helps in making decisions on how to prepare the seed lot for planting. To check a seed lot’s physiological age, place a few tubers in the dark at about 18 C for a few weeks and watch how the sprouts grow. If there are no sprouts, then the seed is still dormant. If only one or a few big sprouts occur at the apical end, then the seed is young. If sprouts are coming from many eyes, then it is middle-aged. If the sprouts are branched, then the seed is old – too old to produce a vigorous stand. ABOVE: T by Carolyn King Selecting seed When it comes to seed selection, seed health is top priority. “Healthy seed is the foundation of a high-quality crop and high marketable yield. Management practices will not make up for a seed lot with poor vigour,” says Eugenia Banks, a potato consultant for the Ontario Potato Board. “Growers strive to produce a complete stand of uniform plants with the potential for high yield and quality. That requires quality seed.” She identifies key factors to consider when selecting seed: “Choose seed that has been inspected by the Canadian Food Inspection Agency (CFIA) and graded as certified or higher class. The seed should be essentially free from seedborne diseases including Fusarium dry rot, late blight, soft rot, common scab and Rhizoctonia. There should be no stem-end discoloration. “The seed should be firm, not spongy; firmness indicates it was stored properly. The seed should have a uniform size and no tuber defects, and it should be true to type,” Banks says. Healthy seed is the foundation of a high-quality crop. 8 TOP CROP MANAGER/POTATOES IN CANADA | Spring 2018 FILE PHOTO.