Wet weather preceding warm temperatures and dry days creates the perfect environment for farmers hoping to capitalize on an early corn crop. In southeast Kansas, soil conditions are on the verge of excellence and many fields have already played host to planters.
“It’s not uncommon for us to plant corn this early in the southeastern part of the state,” said James Coover, Wildcat Extension District agronomy specialist. “Corn requires 50 degree soil temperatures at the bare minimum and really it’s best to to plant in at least 55 degree soil.”
Early April isn’t an unheard of time to plant corn, especially in the far southern corner of the state, but with soil temperatures teetering around optimal levels, early planters face a few inherent risks, all of which can be tied to slow emergence.
Planting Early: Risk One
Uneven stands or uneven germination are the most relevant risks to planting early for the 2021 corn crop based on current soil conditions, Coover said.
“An uneven stand or uneven germination gives you issues with population control,” Coover said. “If you’re not getting that precise placement for growth, you’ll end up with uneven corn like we saw last year.”
Planting in wet soil too early could also cause planters to smear the sidewalls of the row, keeping the seed from gaining good soil contact and stopping the roots from being able to fully extend later on in the growing season.
Planting corn in cold soils increases the risk of herbicide damage to the seed from pre-plant herbicides, which are designed for plants that progress through germination rapidly.
“The reason corn and wheat and soybeans all work well with pre-plant herbicides is because they shoot up through the soil quickly,” Coover said. “If they don’t move quickly, there’s a higher risk of the herbicide actually damaging the seed.”
Sluggish growth in cool soils will be a concern of the past for most producers as temperatures warm, but for the earliest planters, herbicide damage is a factor to keep in mind as corn matures, especially if it shows some signs of injury.
“It’s not a huge risk and it would take a long time to sustain damage because corn is already fairly resistant to anything we put in the soil,” Coover said. “But it is a possibility and I’ve seen cases where there was no other logical explanation for the condition of the corn other than damage by pre-plant herbicide.”
“The risk I would be least concerned about is imbibing damage,” Coover said.
As soil temperatures warm, imbibing damage becomes less and less of a risk.
“Corn takes in 50 to 75% of it’s water in the first 24 hours after planting,” Coover said. “If the water is below 55 degrees there is potential damage to the corn.”
Imbibing damage causes pigtail-type corn that twists in the corners, Coover said. The risk for imbibing damage is heightened if a cold rain also comes shortly after planting.
Currently conditions don’t seem to be favorable for this type of damage specifically because soil temperatures are warming and there is little rain in the forecast.
For producers planting corn slightly ahead of schedule, or in borderline soil temperatures, Coover said coated seed can help early corn get the best possible start.
“If you’re going to plant corn early, it is always a very good suggestion to use coated seed,” Coover said. “Insecticide becomes much more important when you’re planting in cold soil to help the seed resist the onslaught just a little bit longer.”
Early-planted corn also has a greater need for starter fertilizer because of soil temperature.
“Corn has a harder time pulling in phosphorus in cold soils,” Coover said. “Even in fields that test at a normal level for phosphorus can gain a small advantage from starter fertilizer.”
Watchful Over Wheat
Wheat is progressing quickly, close to jointing or newly jointed in most areas. All wheat is well past first hollow stem stage in southeastern Kansas and shows little to no signs of damage from the last hard freeze.
“Now is the time when maximum nitrogen uptake begins,” Coover said. “It’s almost an exponential curve at this point.”
At jointing, wheat becomes difficult to topdress without causing damage, although in some situations an application may be worthwhile if the wheat hasn’t had extra nitrogen or begins to show serious sign of a deficiency.
The time to scout for diseases and deficiencies is approaching faster than expected, with early reports of rust as far north as Stillwater and a wide variety of other complications to monitor, including Barely Yellow Dwarf, which can masquerade as a simpler nutrient deficiency.
“We don’t have a lot of issues with mosaic –type viruses in wheat around here, those are mostly in Western Kansas,” Coover said. “We do have significant issues with Barley Yellow Dwarf.”
Barley Yellow Dwarf is carried by an aphid in the fall and progresses no real treatment options. The affected wheat will look yellow like a deficiency driving down the road but up close the coloring is subtly different with a spotty, purple-red tint to the leaf tips.
Overall, Coover said wheat acres have risen slightly compared to previous years, with the added implication of more double-crop soybeans farmed as well.
“I do anticipate there being slightly less corn acres planted this year, simply because wheat was an easy thing to plant last fall,” Coover said. “The corn market is good, but the soybean market is awesome, so I can see more double-crop and full season beans over corn.”