Deadlines, Rotations Loom Over Remaining Acres

“Canola actually holds on to its yield quite a bit better into that first week of June and so does something like sunflowers versus flax.”


Normally farmers seed crops in a certain order, starting with cereals, followed by canola, then corn and then, by mid-to late May, soybeans and edible beans.

But 2009 isn’t normal. It’s late May, so farmers with both wheat and beans still to plant might want to seed their beans first, if the soil is warm enough (12 to 15C), according to Bruce Brolley, Manitoba Agriculture, Food and Rural Initiatives’ (MAFRI) business development specialist for pulses.

“You need to be prepared to plant (beans) as soon as the land is right from a temperature point of view,” he said last week.

“Anytime you can get into the field without making wheel tracks (not ruts) after May 21 is a good time to plant soybeans.”

Usually the earlier a crop is planted after the danger of spring frost has passed, the better the crop’s yield potential. But Manitoba Agricultural Services Corp. (MASC) data show that by late May, sunflowers, canola, soybean and edible beans have greater yield potential and higher economic return than other crops such as cereals or peas.

By the end of May, corn in Area 1 (the warmest area of south-central Manitoba), on average, can still reach 94 per cent of its yield potential, although province-wide it drops to 84 per cent, said Pam de Rocquigny, MAFRI’s business development manager for feed grains.

Deadlines to get full crop insurance coverage are another factor to consider when picking which crops to seed next. The deadline for corn in Area

1 is June 6 and in Areas 2, 3 and 4, May 30. There are extended deadlines for reduced coverage.

Contact your local MASC office or visit deadlines. html for seeding deadline dates.

Corn growers seeding in late May should consider planting an earlier-maturing variety. The same holds for soybeans.


If it gets too late, don’t be afraid to drop soybeans and plant another crop, Brolley said.

“That’s a tough thing to do but sometimes that’s the best thing to do,” he said. “Crop insurance data shows us there is such a thing as being too late. With soybeans every three-day delay in seeding is one day later maturity. Our fall killing frost can be Sept. 18 or so.”

Flax is often a crop farmers turn to when seeding late, but its yield potential drops quickly when the oilseed is seeded in June, said Anastasia Kubinec, MAFRI’s business development specialist for oilseeds.

“Canola actually holds on to its yield quite a bit better into that first week of June and so does something like sunflowers versus flax,” she said. “The good thing about flax, though, is it handles fall frost better than canola. If something has to sit out there, flax seems to do better with the weathering than canola would or even wheat. The grade doesn’t drop as quickly.”

Flax also requires fewer inputs, so it’s less risky to grow. However, pedigreed flax seed is in short supply, Kubinec said.

MAFRI’s Red River GO Centre says farmers faced with late planting need to consider the crop type and variety selection, with a focus on maturity and disease resistance.

Barley doesn’t perform well if seeded after June 1, so the earliest-maturing varieties should be seeded.

Wheat may be seeded later but the chances of fall frost damage increase considerably. MAFRI says to avoid Prairie spring varieties, as seeding delays will result in lower yields.

Check Seed Manitoba 2009, available online at www.seedmb.caor through the Co-operator’s website, for information on crop maturity and disease tolerance.


Farmers reseeding winter wheat fields have some tough decisions to make too. In many cases more nitrogen has been applied than cereal crops can use. Corn is a good alternative, but many farmers will be tempted to plant canola, even if canola had been planted in the same field last year. That greatly increases the risk of a severe sclerotinia infection this year and blackleg in the future, Kubinec said.

“If farmers are going that route, I would say be very cautious and be scouting your field quite a bit in anticipation of a fungicide application for sclerotinia,” she said.

Ideally in Manitoba, where canola is at a high risk for disease, the crop should only be seeded on the same land one out of every four years.

Sunflowers can use the nitrogen in aborted winter wheat fields, but they’re also susceptible to sclerotinia.

Before seeding into a failed winter wheat field, de Rocquigny recommends applying glyphosate. That’s the most effective way to kill surviving winter wheat so it doesn’t compete with the new crop.

It’s even more important if the farmer is seeding spring wheat. Surviving winter wheat can harbour wheat streak mosaic and the wheat curl mite that carries the viral disease, which, via the so-called “green bridge,” can spread to the spring wheat.

Winter wheat volunteers can also produce seed, which in high enough amounts can downgrade spring wheat when delivered to the elevator.

Here are some tips from MAFRI for late seeding:

Up your seeding rate to boost the plant population. A good stand results in more even maturation and competes better against weeds. Increase the seeding rate of flax to 40 pounds an acre, Kubinec advises. Only 50 to 60 per cent of the flax seed planted makes it out of the ground, she said.

Don’t “mud” in the crop. As tempting as it might be, planting when it’s too wet will only make matters worse.

“You only get once chance to seed it properly,” Kubinec said. “So it’s either seed it properly and hope the rest of the summer goes along well and your management is there or mud it in and have a number of issues for the entire summer regardless of what the weather is.”

For example, there’s a 50 per cent risk of killing frost at Dugald by Sept. 18. Delaying seeding from May 25 to May 27 cuts the number of Crop Heat Units by 31 out of 2300 for the growing season.

Slow down. Seeding too quickly results in varying seeding depths, which causes uneven germination and maturation. Even spacing between plants is important for crops such as corn, sunflowers and beans.

Don’t abandon your crop rotation if you don’t have to.

Flooded fields may have lost fall-applied nitrogen, but as crops are seeded later they require less nitrogen because the potential yield is lower. [email protected]

About the author


Allan Dawson

Allan Dawson is a reporter with the Manitoba Co-operator based near Miami, Man. Covering agriculture since 1980, Dawson has spent most of his career with the Co-operator except for several years with Farmers’ Independent Weekly and before that a Morden-Winkler area radio station.



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