Source: Saskatchewan Agriculture and Food
It’s a gamble every year, timing out when the canola crop has turned to maximize your yield.
The task might be more difficult than usual this year, but a little patience can pay off with more canola in the bin.
Saskatchewan agronomy specialist David Vanthuyne from the Canola Council of Canada says this growing season will present even more of a challenge than usual. Vanthuyne says growing conditions will see many canola fields mature at different stages, and advises growers to stay off the swather until sufficient seed colour change has occurred in the crop.
The challenge is that crops don’t come with a best before date, or a “time to harvest” indicator, he noted. As a result, averaging out seed colour change on a number of plants in several locations within a given field will be the most profitable approach this year.
“We’ve extended the swathing recommendation window to up to 60 per cent seed colour change from our old recommendation of 30 to 40 per cent,” Vanthuyne said. “Unfortunately, variations in maturity in many areas this year will make determining when to swath more difficult.”
As a result, he adds that proper staging of the crop will be critical.
“Some plants may be at 60 to 70 per cent seed colour change, while others may only be at 20 to 30 per cent seed colour change,” Vanthuyne said. “The trick is to capture as much yield as possible by delaying swathing long enough, avoiding shattering losses, but allowing as much seed colour change as possible on less mature plants.”
When seeds in the bottom half of the plant have changed colour, seeds in the top, or last-formed pods, will be firm and roll between the fingertips. At this stage of maturity, Vanthuyne says the risk of locking in green seed can be minimized.
To be considered sufficiently “colour changed,” green seeds must have at least small patches of colour or spotting. Seeds slowly turn from green to light yellow or reddish-brown to black, depending on the weather and variety. Seed colour change within pods on the main stem will advance about 10 per cent every two to three days under normal environmental conditions.
Under normal growing conditions, sampling the field every two to three days and averaging the percentage of seed colour change will give growers an accurate assessment of the overall maturity of the crop. Plant densities, soil type, topography, variety choice, and weather will affect the rate of seed maturation.
Vanthuyne says it’s a good idea to walk out and sample at least five plants in different areas of the field. Some varieties will show pod colour change long before the seeds do, while the opposite can also hold true. That’s why it is important for producers to check for seed colour change, not pod colour change.
To catch most of the crop at or near the optimum stage, Vanthuyne notes that growers with large acreages may need to start swathing their earliest maturing fields prior to 40 per cent in order to maintain an average seed colour change of 40 to 60 per cent for the bulk of the crop.
Hot, dry and windy weather can also cause rapid seed moisture loss and seed colour change. “We’ve seen seeds on the main stem change from 10 per cent to 50 per cent in just a few days under these conditions,” Vanthuyne cautioned.
“Patience and averaging seed colour change will be the key this year.”
For more information, contact:
David Vanthuyne, Eastern Saskatchewan Agronomy Specialist
Canola Council of Canada
Phone: (306) 946-3588
It’s a gamble every year, timing out when the canola crop has turned to maximize your yield.
The task might be more difficult than usual this year, but a little patience can pay off with more canola in the bin.
Saskatchewan agronomy specialist David Vanthuyne from the Canola Council of Canada says this growing season will present even more of a challenge than usual. Vanthuyne says growing conditions will see many canola fields mature at different stages, and advises growers to stay off the swather until sufficient seed colour change has occurred in the crop.
The challenge is that crops don’t come with a best before date, or a “time to harvest” indicator, he noted. As a result, averaging out seed colour change on a number of plants in several locations within a given field will be the most profitable approach this year.
“We’ve extended the swathing recommendation window to up to 60 per cent seed colour change from our old recommendation of 30 to 40 per cent,” Vanthuyne said. “Unfortunately, variations in maturity in many areas this year will make determining when to swath more difficult.”
As a result, he adds that proper staging of the crop will be critical.
“Some plants may be at 60 to 70 per cent seed colour change, while others may only be at 20 to 30 per cent seed colour change,” Vanthuyne said. “The trick is to capture as much yield as possible by delaying swathing long enough, avoiding shattering losses, but allowing as much seed colour change as possible on less mature plants.”
When seeds in the bottom half of the plant have changed colour, seeds in the top, or last-formed pods, will be firm and roll between the fingertips. At this stage of maturity, Vanthuyne says the risk of locking in green seed can be minimized.
To be considered sufficiently “colour changed,” green seeds must have at least small patches of colour or spotting. Seeds slowly turn from green to light yellow or reddish-brown to black, depending on the weather and variety. Seed colour change within pods on the main stem will advance about 10 per cent every two to three days under normal environmental conditions.
Under normal growing conditions, sampling the field every two to three days and averaging the percentage of seed colour change will give growers an accurate assessment of the overall maturity of the crop. Plant densities, soil type, topography, variety choice, and weather will affect the rate of seed maturation.
Vanthuyne says it’s a good idea to walk out and sample at least five plants in different areas of the field. Some varieties will show pod colour change long before the seeds do, while the opposite can also hold true. That’s why it is important for producers to check for seed colour change, not pod colour change.
To catch most of the crop at or near the optimum stage, Vanthuyne notes that growers with large acreages may need to start swathing their earliest maturing fields prior to 40 per cent in order to maintain an average seed colour change of 40 to 60 per cent for the bulk of the crop.
Hot, dry and windy weather can also cause rapid seed moisture loss and seed colour change. “We’ve seen seeds on the main stem change from 10 per cent to 50 per cent in just a few days under these conditions,” Vanthuyne cautioned.
“Patience and averaging seed colour change will be the key this year.”
For more information, contact:
David Vanthuyne, Eastern Saskatchewan Agronomy Specialist
Canola Council of Canada
Phone: (306) 946-3588
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