Nearly 80 percent of Mississippi’s corn crop is safely in storage, and the remaining acres are ready for harvest but stuck in wet fields getting rain-drenched for days.

Erick Larson, grain crops agronomist with the Mississippi State University Extension Service, said the corn harvest is largely complete in the southern part of the state, including the south Delta. However, the corn in the northern areas of the state was planted later and most remains in the fields.

“All the corn is mature,” Larson said. “Corn is naturally protected somewhat from rainfall if the ears tip over after the plants reach physiological maturity. Not all ears do that, and the number of ears tipping over can vary substantially from field to field. If it doesn’t tip over, water can collect and the husk holds it in the ear.”

Kernels that stay wet for too long may sprout, and Larson said he already has heard reports of that happening. A sprouted kernel is considered damaged, reducing the overall quality of the corn.

“The biggest problem we have with sustained rains at this point is grain sprouting and reduced test weights,” Larson said. “The grain begins to deteriorate if it is continually exposed to this wet environment.”

Larson said the entire year has been tough for the corn crop. Soils were too wet to plant during the optimum planting window, then May was an extremely wet month.

“Wet weather during the spring, especially during May, stunted the crop in late vegetative stages and restricted root growth. This substantially reduced yield potential before it faced difficulties later in the summer,” Larson said. “Spring rains also limited both fertilizer and herbicide applications during key times.”

June’s weather turned off extremely hot and dry, and the drastic change of environmental conditions shocked the plants, Larson said.

“When the hot, dry weather came, the corn suffered because it did not have the root system it needed,” Larson said.

Yields have been lower than average on the corn harvested to date, and Larson said yields on dryland and irrigated fields varied from what is typical.

“Irrigation helps minimize drought stress during June, but drought stress was generally not our most limiting factor this year,” Larson said. “The wet May stunted the plants and limited our yield from the outset.”

Early-planted fields and those in southern Mississippi generally suffered more because they matured before the rainfall and cooler conditions of late July and August. Most corn in the northern part of the state was planted later. Larson predicted those fields will yield better than what that region has seen for years if harvest is not hampered substantially by recent, monsoon-like weather.

“Their corn was able to take advantage of some timely rainfall in June and some pretty abundant rainfall and relatively cool temperatures in July and August, which benefited that crop much more substantially than it did the crop in other regions of the state,” Larson said.

The U.S. Department of Agriculture is predicting yields of 137 bushels an acre, but Larson said he expects actual totals to end up lower than that. State corn fields yielded a record 148 bushels an acre in 2007 and dipped to 140 bushels an acre in 2008.

“We hopefully won’t dip below the five-year yield average of 131 bushels an acre, but the profit margin is so slim that we really hate to lose that much potential,” Larson said.

John Michael Riley, Extension agricultural economist, said December corn futures prices are at $3.26 a bushel, which should be about a break-even price for growers. Corn prices have remained fairly steady this year, but they are down drastically from the just under $8 a bushel price corn reached in 2008.

“Not including last year, corn prices had averaged about $2.25 to $2.50 across the nation in previous years,” Riley said. “Although we’re above that average, a lot of people are seeing this $3.26 and saying that it is too low. When the crop was planted, input costs were high — not as high as last year, but still high.”