Any life left in dry fields?
For those corn and soybean fields that already look pretty well cooked, is there any hope of recovery before you fire up the combine? The eastern Corn Belt has seen rain -- some heavy -- over the last few days, but is it too late?
"If there is no green color left on either corn or soybean at this point, then there is little or no chance to add yield,” says University of Illinois Extension agronomist Emerson Nafziger. “No green leaf area means no more photosynthesis; the ‘factory is closed’ for this crop.”
In university trials, Nafziger says the corn that was planted on the last day of March has matured and is in the lower 20% range for moisture. But, most soybeans are still green or have some green leaves.
“In very dry areas, plants without green leaf area may have died early, without completely filling the seeds,” he says. “In corn, if kernels still have a milkline, with fluid at the base of kernels, they might still be able to receive some sugars from the stalk. But stalks in such fields have probably been depleted of sugars by now, and it’s unlikely that yields will increase further.”
So, the crop's not likely to gain much, yield-wise, between now and harvest time. But, the good news is that with things starting to cool off outside, the damage incurred from continued dry conditions will likely slow up dramatically.
“The return to cool weather likely has helped the crop cope with water shortage by lowering water use rates,” Nafziger says. “But lower water use rates and low temperatures mean lower photosynthetic rates, and so we expect that yield is being added slowly in most soybean fields. This will speed up as it warms up again, but senescence may not be far behind.”