One of the keys to a high-yielding corn crop is even, uniform emergence.
Growers can achieve this management goal in early-planted April crops when soil conditions are fit, but what happens when the weather turns bad and soil conditions take a turn for the worst at planting?
On this episode of Corn School, Ken Currah, BASF Canada agronomist and business representative, shares some research from the company that demonstrates both winning and losing planting scenarios from spring 2020 in Ontario. The company planted corn research plots on May 7, 8, 9 and 13 to test the effect of planting date, depth, and cold weather on corn emergence. Corn was planted at depths of 2″ and 3″ in all the trials.
Currah notes that the research provided some excellent insights based on the arrival of freezing temperatures after the May 7 trial was planted and a May 9 snowfall, 72 hours before the final trial was planted.
Overall, the results of flag tests, which marked emergence timings of seed in the trials, highlighted several key takeaways for growers, says Currah. For starters, if the weather forecast is calling for cold weather, it’s important to assess soil conditions and determine whether there is risk of imbibitional chilling. If growers can get the seed in the ground 48 hours before the chill and ensure that the seed’s first drink of water is a warm one, the risk is minimal, says Currah.
When it comes to planting depth, Currah notes that it makes sense to plant deeper than 2.5 inches on lighter soils to protect the emerging coleoptile from a late frost. But beyond that scenario, planting and soil conditions really need to be optimal to push the seed that deep. Otherwise, the 2″ depth is a better option.
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