It’s May 29, and Ontario Ministry of Agriculture soybean specialist Horst Bohner has yet to plant any soybeans.
It’s the latest planting season he’s experienced in 18 years on the job. It’s the same story for growers across the Ontario where soybean planting is estimated at five to 10 per cent complete. As the rain continues to fall and temperatures remain cool, Bohner is telling soybean growers not to panic.
In this episode of RealAgriculture Soybean School, Bohner emphasizes that adapted soybean varieties still have over 90 percent yield potential when planted in early June. That’s why he’s not recommending growers make the switch to earlier varieties just yet. Research showing soybeans produce higher yields with earlier planting has prompted growers to rev up the planter as early as possible, but “even a late May planting is considered normal for soybeans, so no changes are required,” says Bohner. (Story continues after the video.)
If planting is delayed beyond June 1, however, growers need to assess their varieties. If a variety is considered long for a given area, it’s a good strategy to move to an adapted variety. If fields are intended for winter wheat, it’s best to switch to a lower maturity group to ensure a timely harvest. Should planting be delayed past June 15th, Bohner recommends growers exchange the variety for one that is 0.5 to 1.0 maturity less — he breaks down the choice in more detail here.
Bohner also discusses the need to adjust row width and seeding rates as planting pushes into June. “Since later planting will result in plants with fewer pods, the only way to compensate is to increase the number of plants per acre. Since the plants will not grow as tall, more plants can be sustained per acre. If planting is delayed into June, start to increase seeding rates,” he says. “By the 15th of June increase seeding rates by at least 10 percent for a minimum of 200 000 seeds per acre in narrow rows. This will increase the height of the lowest pods as well as the number of pods per acre.”
Bohner notes that planting in wide rows (30 inches) in June will lead to reduced yield potential. “Too much sunlight is wasted on the bare ground because the rows do not close before early pod set. Ideally, 7.5-inch rows should be used when seeding is delayed past the middle of June. A combination of narrow rows and increased seeding rates can make a significant impact on yield.”
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