Will time run out on 2013 crops?
There have been a lot of reports of trend or higher corn yield potential around the Corn Belt. It's a far cry from a year ago at this time, when some fields were virtually nonexistent because of the major drought.
Although that yield potential is there now, there's growing concern that that potential won't reach fruition because of its late start.
"Late planting and weather that continues to be cooler than normal into August has many wondering if the corn and soybean crops will reach maturity and harvest moisture within a reasonable time this fall. Crop conditions remain good for both crops, but crop development, including pod formation and filling in soybean and grain fill in corn, remains well behind normal," says University of Illinois agronomist Emerson Nafziger. "Corn is 10 days to two weeks behind normal, and soybeans are two to three weeks behind normal. The number of days behind will stretch as the weather cools, so late crops get even later."
Though an early frost and its potential for ruining an otherwise bumper crop is a major concern, it's conditions between now and fall -- namely the accumulation of growing degree days (GDDs) -- that are more important, Nafziger says. Compiling enough GDDs leading up to fall will determine just how much damage the crops will incur from frost once it hits.
"With a 50% frost date of about October 20 here, we would expect a midseason corn hybrid planted in early June to mature before frost, if frost does not occur before its normal (50%) date," Nafziger says. "But drydown slows quickly as we move into October, and even early-planted corn will dry slowly after maturity unless September is unusually warm. Corn planted in mid-June (some fields in central Illinois are still not pollinated) is unlikely to mature before frost if temperatures are normal and frost comes at its normal time."
A recent crop tour shows the general condition of the corn crop is better than for soybeans. As far behind as both crops are right now, the prospects for successfully weathering a frost while they're still developing are better for soybeans.
"Good soybean yields are still possible if the weather remains good into September, but seed filling rates will remain slow as long as temperatures remain low. We have sometimes seen cool temperatures trigger maturity before seeds are fully filled," Nafziger says. "The best scenario for soybeans would be a return to temperatures – both day and night – to normal or a little above normal, with enough rainfall to enable the crop to photosynthesize fully as seeds fill. Even with that, we’re in for a wait to see how the crop finishes this fall."