Canola growers are casting more than one mournful look to the field after an unseasonable snow dump and chilly rain stopped harvest in its tracks.
Manitoba’s weather took a turn to the cold and wet in the last weeks of September, with many regions reporting rain, temperatures well below 10 C and, in a stark reminder of fall 2016, which left millions of unharvested acres to overwinter across the Prairies, the first substantial snowfalls of the year.
According to community precipitation monitor CoCoRaHS, Neepawa saw two inches of snow from Sept. 10 to Oct. 1, while Manitoba Hydro was working to restore power to a swath of the province stretching from the Parkland to Steinbach after power lines were weighed down by several inches of snow Sept. 22, according to the company’s Twitter feed.
“I think this has to be one of the coolest Septembers that I’ve ever experienced,” Angela Brackenreed, agronomy specialist with the Canola Council of Canada, said during a late-September Crop Talk webinar.
Manitoba Agriculture estimates about 15 per cent of Manitoba’s canola acres were unharvested as of the last week of September, although Brackenreed expects the hit to be substantially higher in the north. Areas north of Highway 1 and Highway 16 had a “mixed bag” of both swathed and standing canola in the field, she said, and canola harvest in areas like The Pas had just got underway when the cold weather hit.
Brackenreed urged growers to consider maturity when managing the snow-laden crop. An immature crop strategy should mimic management for frost, she said.
Growers will not be able to dodge green seed if crops sat over 20 per cent moisture, or less than 50 to 60 per cent seed colour change.
“I think the big question for these immature standing crops is, should they be swathed?” Brackenreed said. “The question in my mind is, will there be a yield penalty for cutting early in the sort of conditions that we’ve been experiencing?”
She would normally recommend avoiding an early swath, she said. This year, however, cold and damp may actually mean less yield penalty, compared to the more typical 20 C heat and bright sunshine.
“I will say though that the goal of swathing in this situation needs to be to preserve the yield and to bring about maturity quicker,” she said. “We can’t help the green seed issue or, if we can, it’s in a very insignificant way.”
Growers should also brace for higher green seed counts if the immature crop was in the swath when the cold hit, although the swath may have held moisture and limited frost damage.
The effect of mature crops may have been more akin to rain, she said, although many standing canola acres have also lodged under the weight of the snow. Brackenreed cautiously urged farmers to wait for better weather if crop was mature. Wet crops may yet dry, she said, assuming that the forecast takes a turn for the better.
Her caution, however, stems from what is, so far, an unfriendly forecast for drying. Rain and snow still featured in forecasts for much of agro-Manitoba as of Oct. 1, with temperatures not expected to break 15 C.
There is little answer for snow-flattened crops, although Brackenreed urged producers with mature standing crops to avoid swathing.
“Just plan to straight cut it whenever things dry down and it’s really going to be trial and error, trying different angles to see how we can get this crop to feed and potentially adding crop lifters could certainly help,” she said.
Bring on the heat
Farmers relying on natural air-drying will want to take a hard look at supplemental heat this year, Joy Agnew, program manager with the Prairie Agricultural Machinery Institute, said.
“The concept of adding heat to the air, not to the level of a heated air-dryer but just a little heat added to the natural air systems, is very effective if it’s done correctly,” she said, although any producers struggle with matching temperature to airflow.
“Airflow rate, they should be at least somewhat familiar with because you want a certain amount of cfm (cubic feet per minute) even for natural air-drying, but the target amount of airflow for supplemental heat is even more critical,” she said. “You absolutely need at least 0.75 cfm/bushel if you’re adding any heat, otherwise you don’t have enough energy or removal capacity to pull the moisture that is being pulled out of the grain out of the bin.”
Brackenreed has made similar arguments. Air at 18 C will dry grain about five times faster than air at 10 C, she said, while every 10 C change in air temperature will cut the relative humidity in half. In the same breath, the agronomist also urged producers to consider ventilation and airflow, since removed moisture will condense on the ceiling of a poorly ventilated bin and anything less than 0.75 cfm/bushel may risk baking grain closest to the fan.
Underfilling a bin may also help deal with difficult drying conditions, Brackenreed said, along with frequent turning, careful monitoring and constant aeration, if only to cool grain and forestall spoilage.
By the same token, growers may want to avoid blending dry and damp canola.
“The moisture will transfer from your wet canola to your dry canola and now you’re putting everything at risk,” Brackenreed said. “The only reason that I would ever do this is if I was selling it right away.”
Farmers would actually be better to pile damp canola on top of dry grain, if they have nowhere else to store it, she said. Air would then move easily through the dry canola and work on wet grain on top.