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Speeding up crop maturity

Consider these nine factors to make sure you have time to get your crop in the bin in 2020

The 2019 harvest on the Prairies left little to be desired, with crops still left in fields for a good number of farmers.

Last season, 2019, was a bad crop-growing season on the Canadian Prairies. There are various estimates of 10 to 25 per cent of all crops left unharvested in swaths or even still standing on cropland. Well, in that case, 75 to 90 per cent of the crop is in the bin, despite the weather. Lots of grain drying took place but even so, most producers had successful harvests. Now these snow-covered unharvested swaths and even standing crops will sit out in the fields over winter. Most of these crops will be harvested in the spring of 2020 but quality will generally be poor.

What did the successful producers do to get their crops in the bin?

1. Seeding date

It started out as an unusually cold spring with growers holding back and hoping for warmer weather. How warm should it be for planting cereals, peas, canola and other cold-tolerant crops? Well, 3 C to 5 C at the one- to two-inch level should be fine. Do not guess on soil temperature; get a soil thermometer. Plant by the soil temperature, not by old folk tales. Or by the calendar.

A few years back it was 28 C in late March, perfect for seeding. The successful farmers were seeding in early April. By the traditional seeding time in late April and early May, Prairie soils in many areas got bone dry. Plant-by-calendar farmers seeded into very dry soil. These crops did not germinate until mid-June when the rains came and didn’t get in the bin until mid to late October. They were lucky there was no snowfall or rain that year.

2. Field condition

Unless you are farming sandy, sandy loam or silty soils, clay or clay loam soils can be too wet for early planting, despite favourable soil temperatures.

To improve drainage on clay or clay loam soils avoid fall cultivation. When you cultivate crop stubble in the fall you mess up the natural soil drainage. The crop stubble stems and roots conduct water downwards into the soil profile in early spring and allow you to seed days or even weeks earlier. Fall cultivation also destroys earthworm and insect tunnels that move downward into the soil that again facilitate soil drainage. Resist the urge to cultivate unless you intend to grow late-May seeded crops like corn, soybeans, beans or potatoes. Even for these crops, why fall cultivation?

3. Seed germination

Any seed that you intend to use, particularly saved seed like cereals or peas must be checked for percentage viability. Do not take a chance with old seed or seed from a poor harvest year. Send your seed sample off to a seed diagnostic laboratory in the new year when the seed will have lost its natural dormancy. You can even do a rough count yourself for peas, flax, lentils or cereals. Get a nine-inch plate. Place a double- or triple-folder wet paper towel on the plate. Count out 50 or so random seeds from your wheat bin and plate them separately in rows on the wet/damp paper towel. Plant 25 or 100 if you so wish — get the children to do it! Place the plate and seeded towel into a large, sealed transparent plastic bag. Keep at room temperature (top of the fridge) and check after five to seven days. After 10 days you will get a good idea of your seed viability. If you used glyphosate to speed up your grain harvest and you intend to use this seed, have the seed professionally checked. Seed crops treated with glyphosate may have carry-over chemical which can impact seed vigour and viability.

Seed germination is especially important for crop maturity for cereals, if you use optimum planting rates of 2.5 to three bushels an acre. Some growers even advocate 3.5 to four bushels. Poor or weak germination of less than 60 per cent will cause secondary tillering and delayed maturity. Excellent germination of 90 to 95 per cent at the optimum seeding rate will speed up maturity by giving rise primarily to main tillers, speeding up maturity by seven to 15 days. Low cereal seeding rates will delay crop maturity for weeks. You may save on seed but lose on harvest. Seeding depth even plays a part in earlier emergence. With wheat at just under an inch deep you get earlier emergence.

Seed canola at recommended rates. If you seed canola at four to six pounds per acre the crops should mature by the expected date. Light seeding of less than four pounds can progressively delay maturity in the canola crop, even if it counters lodging to some degree by branching out more.

4. Low phosphate levels

Peas and canola and many other crops are good scavengers of soil phosphate reserves, but this is not so for cereals in low- or phosphate-deficient soils. Low or deficient soil phosphate levels can delay cereal crop maturity by seven to 15 days, but not necessarily affect yield. Skimping on recommended phosphate fertilizer could result in crop swaths overwintering on the fields rather than grain in the bin.

5. Low copper levels

Sandy or high organic soils that makeup about 20 to 25 per cent of Prairie cropland are prone to copper deficiency, especially in wet summers. My former colleagues and I have shown that low or deficient soil copper levels will delay maturity by 10 to 15 days. This does not include the lodging and ergot infection that goes with the maturity delay.

Ignore the naysayers and follow soil-testing recommendations if your soils are found to be low or deficient in copper. Certain cereal herbicides, such as Group 1 herbicides, can induce additional copper deficiency in low-copper soils.

6. Molybdenum deficiency

If molybdenum is unavailable in acidic soils (below pH 5), absent in some soils or leached out in irrigated high pH soils you can get delayed crop maturity. Molybdenum controls nitrogen and sulphur metabolism in the plant as well as some phosphate functions. Drilled-in crushed limestone in the seed row will raise the pH in acidic soils and release soil molybdenum. In naturally molybdenum-deficient soils or on long-term irrigated soils a few ounces of molybdenum per acre will work like magic.

7. Crop variety selection

Do not go for the highest-yielding crop if it takes days longer to mature, especially if you are in a shorter-season growing area. Select shorter-season varieties best-suited for your growing area. Do not gamble on a long growing season. Quality shorter-season varieties are worth more than low quality, higher-yielding long-season types. Ask your neighbours with quality grain in the bin how they accomplished it. It’s much better than trying to guess the best agronomic way.

8. Heat units

Heat units above 2,000 units are most suitable for corn and soybeans. Below 2,000 units small grain cereals, canola, silage corn and peas are the more suitable crops. Heat units across the Prairies from southern Manitoba can be as high as 2,500 units to as low as 1,600 or 1,700 units for the grain varieties that they grow successfully in the Alberta and B.C. Peace Region. Stick to crop varieties that perform well in your area. Check with your farming neighbours this winter.

9. Balanced fertility

With nitrogen as your lead nutrient, all other nutrients from sulphur, potash and phosphate as well as micronutrients should be in adequate supply based on regular soil testing for every field or quarter. Miracles do not happen often, but common sense must prevail which sees you and your neighbours enjoy a fall coffee chat knowing that everything is in the bin for the year.

About the author


Dr. Ieuan Evans is a forensic plant pathologist based in Edmonton, Alta. He can be reached at [email protected]

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