By Emily Unglesbee
DTN Staff Reporter
-- Minimize tillage and wait for dry soils
-- Consider a switch to in-season nitrogen applications and skip other nutrients
-- Don't switch maturity groups yet
-- Stick with planting depths of 1.5 to 2 inches, but consider a lower seeding rate
-- Make sure you have the right Bt traits
ROCKVILLE, Md. (DTN) -- May is nearly upon us, and a lot of corn seed is still in the bag.
According to USDA's Crop Progress reports, the country is already running 10% behind last year's corn planting pace, with much of the Corn Belt expecting more rain this week.
Don't panic, but it may be time to start adjusting your corn-planting practices, Peter Thomison, a corn agronomist with Ohio State University, told DTN.
Here are his five top tips for managing a late-planted corn crop:
1) TILLAGE AND PLANTING
If an extensive tillage program is still standing between you and your corn planter, it might be time to consider skipping or simplifying it, Thomison said.
"We're focused on minimizing soil disturbance right now," he said. "Not only are we worried about soil compaction, but it simply delays planting further, especially if we continue to have sporadic rains in the weeks ahead."
If you must do some tilling, try to limit it to rut repairs, Thomison said. Remember that modern planters have become better at punching through crusted soils for seed placement.
Don't "mud-in" your crop, Thomison added.
"Yield reductions resulting from 'mudding the seed in' are usually much greater than those resulting from a slight planting delay," he explained in an OSU article. The soil compaction that comes along with it can produce sidewall compaction and stunted root systems, which leave plants vulnerable to dry spells, he told DTN.
If you don't have a week to spare between an anhydrous nitrogen application and corn planting, and you have the right equipment, consider switching to starter fertilizer at planting along with a side-dressing pass at V4 to V6, Thomison said.
As for potassium and phosphorus, make sure you really need it before you expend valuable time applying it this spring.
"With these later planting dates, you don't have to worry as much about the roots accessing nutrients because the soil will be warmer and the roots will grow better," Thomison said. "So unless you really have documented major nutrient deficit issues, you can probably avoid adding them because of the calendar date."
Remember that a lot of corn symptoms associated with nutrient deficiencies, such as purpling, are more often the result of poor root systems due to cold, wet conditions, he added.
3) HYBRID MATURITY
It's still too early to worry about switching to an earlier maturing corn hybrid for most Ohio growers, Thomison said. Only if planting gets pushed into late May and early June should growers start to consider switching, he said.
Data from Purdue University in Indiana suggests the same. See some of it here: https://www.agry.purdue.edu/…. For a more northern Midwest perspective, see this article from the University of Wisconsin: http://wisccorn.blogspot.com/…
4) SEEDING DEPTH AND RATE
Stick with the 1.5-to-2-inch planting depth recommendations, regardless of your planting date, Thomison cautioned.
The topmost layer of soil is subject to way too much temperature and moisture fluctuations to be safe for a corn seedlings, he explained. "We get more erratic stands with shallow planting," he said.
Late planting is a good opportunity to save on seed costs by lowering your seeding rate, however.
"Germination rates get higher with warmer conditions, so you have better emergence and the chance for plant mortality is reduced," Thomison explained.
5) INSECTS TO WATCH
Late-planted corn will be younger and more susceptible when certain insects come calling, namely lepidopteran pests such as European corn borer, corn earworm, western bean cutworm and fall armyworm.
Check your corn hybrids to make sure that they have the Bt traits that target these pests, using the Handy Bt Trait Table from Michigan State University. The table can be found at: https://lubbock.tamu.edu/…
Remember that only Syngenta's Vip3a protein is effective against western bean cutworm. Hybrids with the Herculex trait (Cry1F) will no longer protect against this pest. See DTN stories on that resistance issue at: https://www.dtnpf.com/…
See Thomison's article on adjusting corn management for late planting for more details: (https://agcrops.osu.edu/…
Emily Unglesbee can be reached at Emily.firstname.lastname@example.org
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