Things to remember in the spring for potato production

The potato is one of the more complex crops to grow, and potatoes require intensive management to ensure success. Mother Nature plays the biggest role in determining what pests appear; in wet years, diseases like late blight, white mold, Botrytis grey mold and pink rot are major problems. By contrast, insect populations develop faster in dry years. Readiness is everything, and readiness is helped by implementing management practices that reduce the incidence of pests. What follows is a list for growers of the 20 things they should not forget in the Spring

Field selection

1. Practice crop rotation. This is one of the best management practices to reduce several important diseases and insects.
2. Drainage, soil texture, soil compaction and soil organic matter all have a significant impact on pest development. Varieties very susceptible to late blight should be planted in the lightest-textured field because sandy soils do not remain saturated for long periods after heavy rainfall. Soil compaction reduces soil drainage and favors nematode infestation. Identify compacted soil areas by checking root growth and soil texture in a 3-foot deep trench. Look for excessive clod formation, slow water infiltration, distorted root and tuber growth and premature crop death. These are all signs of shallow rooting.
3. If soil organic-matter is low, incorporate cover crops and/or manure. Cattle manure from large operations is usually free of scab because the cows are not fed cull potatoes. In Ontario, soils high in organic matter rarely have problems with common scab.
4. Check for nematodes, wireworms and white grubs before planting. These pests can cause serious economic losses. Take soil samples for nematode counts, and use baits to trap wireworms. White grubs are usually easy to see when plowing the soil in the spring.
5. Take soil samples to be analyzed for Verticillium before planting. If Verticillium levels in a field are medium to high, do not plant early or susceptible varieties like Superior, Pike or GoldRush.
6. If the field is infested with common scab, grow only resistant varieties.
7. If you are renting land, be aware of previous crops and problem weeds. Some herbicides persist in the soil for several years and damage potatoes.
8. Conduct complete soil tests. Nutrient deficiencies can encourage diseases and limit yield. Soil tests will also allow you save money by applying the right rate of the fertilizers needed.

Field preparation

9. Aim for soil of good tilth without drying out the soil or producing soil clods. Tillage should produce enough loose soil to allow the planter shoe to penetrate to the desired depth and to provide the hiller discs with enough loose soil to construct a proper hill over the seed. Tillage that dries out the soil surface reduces plant vigor. Also, sufficient tillage is required to properly incorporate pre-emergence herbicides

Seed quality and handling

10. Plant healthy seed. Always check seed upon arrival. You have only 48 hrs to contact the Canadian Food Inspection Agency (CFIA) if you detect seed problems.
11. Calibrate the seed cutter. Sharpen knives and sanitize cutting equipment at least once a day and/or when changing seed lots to avoid spreading diseases like dry rot, blackleg and soft rot.
12. Warm seed tubers to 50-550F before cutting. This reduces bruising when handling, promotes rapid healing of cut surfaces and initiates sprouts before planting.
13. Set aside samples of suspicious tubers. Contact your potato specialist or crop consultant if you are uncertain of the cause.
14. Apply the fungicide/insecticide seed treatment you know will be cost effective.
15. If possible, use B-size seed for early planting. Whole seed tolerates cool, wet conditions better than cut seed and is more resistant to soft rot.
16. Destroy slivers and any tuber waste left after cutting.

Planting

17. Make sure the planter is in good condition.
18. Try to schedule planting to coincide with favorable soil and weather conditions. Ideally seed and soil should be the same temperature at planting. Do not plant cold seed in warm soil. The seed will sweat, and this creates favorable conditions for soft rot.
19. Apply seed treatments and in-furrow pesticides depending on anticipated problems.
20. Check the depth and spacing of seed pieces at the beginning of planting and throughout planting. Skips and clumped seed pieces reduce yields. Doubles reduce average tuber size. Plants adjacent to skips don't fully compensate for their missing neighbor.

Image

Fig 1: Healthy seed is the foundation of a high quality crop.