Late greening crops causing headaches for farmers

The weather turnaround has skewed the internal clocks of some crops

A canola field in Manitoba's Interlake, Sept. 26. New growth blooms despite the late-September calendar.

Producers are ready to get that grain in the bin, just as some crops have decided now’s the perfect time for a vegetative growth spurt.

Late-season growth has frustrated harvest and increased the risk of spoilage in a list of crops ranging from canola and flax to pulses, provincial extension staff say.

Why it matters: Recent rain, after a season of hot and dry, is giving the signal for some crops to start growing again like it’s midsummer

Dane Froese, oilseeds specialist with Manitoba Agriculture and Resource Development, says the issue is widespread in canola. Plants in those fields have responded to August rains (after months of heat and drought stress) by going reproductive, in some cases for the first time.

“It’s mostly plants that were already existing that have shut down from reproductive growth from the top down,” he said. “They may have set pods on their first initial bolt and blooms and are now forming a lateral branch that’s regrowing. In some cases, some plants never went reproductive at all. It was so dry and so hot that they stress aborted any kind of seed production.”

Those plants stayed short and dormant, and are now starting the reproductive cycle with the advent of moisture and cooler temperatures.

Canola greens in mid-September. photo: Dane Froese

The issue is most noticeable in stressed, late and reseeded fields, particularly those on lighter or sandier soil, Froese said.

The issue has been especially obvious in the Interlake, an area that has borne the brunt of many of the province’s drought issues this year.

Some flax fields are showing similar issues.


For fields that have little chance of maturing in time for harvest, it may be time to consider calling up crop insurance about alternate use, Froese said.

In fields where green growth is underlying mature plant tops, however, the producer may find desiccation is the better option.

Vegetative growth at canola bases threatens to frustrate harvest. photo: Dane Froese

Product choice, though, may be a little different this year. In a normal year, experts often warn that using glyphosate will kill the plant, but will not help to mature plants to avoid high green seed counts. This year, however, it may be the green vegetative plant bottom, not immature seed up top, that is the problem.

“It might be advantageous in some cases to use a slower-acting product,” Froese said, noting that such products would provide a “slower, more effective kill down at the base.”

Tough harvest

Increased green material at harvest has also increased the chance of seed loss while combining, something Froese notes is of particular concern this year, with canola prices so high.

“Almost everybody” has experienced higher seed losses this season, Froese said.

“Even with finer-tuned adjustments, just the nature of seed moisture and green material moving through the combine means it’s harder to retain that seed, and then that seed is smaller and lighter to begin with,” he said.

Producers wanting to swath may face yet another challenge.

“Remember that what you’re doing is just cutting off the top of the plant. It’s not killed down to the base and it doesn’t have that strong environmental signal to shut down right now,” Froese said. “So the base of the plant, where it’s throwing lateral branches, could easily green up and start growing again within a week and then you’ve got canola lying in swaths, or green plants lying in swaths, trying to dry down, but it’s still growing green all around it.”

At that point, he noted, combines will have a hard time picking up crop, while green material is getting into the hopper.

Flax flowers and mature pods share a plant in a phenomenon that experts say is rooted in drought and heat, followed by recent rain. photo: Dane Froese

For crop that does make it to the bin, that increased green material brings yet another problem: moisture, and with it, the risk of spoilage.

Oilseed experts have warned producers to be ready to jump on drying and aeration this year in an effort to mitigate those losses.

“The best piece of advice would be to understand the uniformity of your crop,” Froese said. “To scout and know, is it a large portion of your field? Is it a small portion? Is it underlying the entire canopy throughout the entire field? Where are you at and where is your crop at in terms of ripeness?”


Provincial pulse specialist Dennis Lange has likewise noted issues with delayed growth in edible beans, although he says those issues are anecdotal rather than widespread.

In one case, a field of pinto beans on sandy soil, plants appeared much as the producer might expect, assuming it was still late July. There were few pods throughout the field, Lange noted, and only sporadic mature plants.

“What I’m thinking is happening here is, because it was so hot and dry this summer during the flowering period, that those plants just kind of stopped, and then with those late rains, something with the apical dominance, possibly, has changed, so now things are starting to regrow again,” he said. “It’s very unusual to see a whole field like that.”

There is little the producer can do in that instance, he also noted, since there is little chance that anything in that field will mature by season’s end.

Pinto beans photographed in mid-September appear to have a development stage better suited for July. photo: Dennis Lange

Another field of edible beans showed pods changing colour, but plants had suddenly started to regrow.

In the second case, Lange noted, the producer’s greatest friend might be patience. As long as fields can dodge a frost, producers may be able to give those delayed plants enough time to mature or, at the very least, mature to the proper stage for desiccation

Lange is investigating a similar call of delayed growth in soybeans.

About the author


Alexis Stockford

Alexis Stockford is a journalist and photographer with the Manitoba Co-operator. She previously reported with the Morden Times and was news editor of  campus newspaper, The Omega, at Thompson Rivers University in Kamloops, BC. She grew up on a mixed farm near Miami, Man.

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