May 9, 2008

Give canola a fighting chance by seeding smart this spring. Careless or rushed seeding can produce uneven crop stands, and that can cost big time, says Doug Moisey, Canola Council agronomy specialist. 

Recent research has shown that uneven stands averaging 4 plants/ft² could cost as much as 21 percent in yield when compared to an even plant stand of 8 plants/ft² under normal conditions. In uniform stands of 4 and 8 plants/ft², there was no significant difference in yield, emphasizing the benefit of an even stand, Moisey points out. 

Based on a 30 bu/ac average yield, a 20 percent loss is 6 bu/ac. At $12/bu, the cost of an uneven plant stand can be more than $72/ac. Multiplied by 640 acres, that’s a potential loss of over $46,000. 

Do it right the first time

“We know seeding early is good, but going into cold soils can put stress on germinating seedlings,” says Moisey. “Ideal soil temperature is above 10 ºC at seeding depth, but you can reasonably start seeding canola at 4-5 ºC.”

When seeding canola into cool soil, keep these tips in mind:

• Seed shallow (½ to ¾”).
• Maintain a reasonable seeding rate as emergence may be variable in the field. Germination values don’t equate to emergence values in the field.
• Place some phosphate fertilizer with the seed.
• Seed slowly to ensure uniform seed distribution, depth, and proper fertilizer/seed separation in single-pass seeding systems. Check seeding depth periodically.  

“Achieving good, uniform plants stands is critical for canola,” says Moisey. “It will make the crop more competitive, and uniform crop development simplifies pest and harvest management later in the season.”

Ideal plant population is 7-14 plants/ft². He recommends targeting 10 plants/ft², remembering that emergence is typically 50 percent in western Canada (Hybrids can be 10 percent higher). Use 50-60 percent emergence when calculating seeding rates unless your own evidence has established a different baseline level.