MISSISSIPPI STATE -- Saturated soils in some parts of the state are complicating management decisions for corn farmers and increasing the likelihood of reduced yields.

Erick Larson, grain crops specialist with Mississippi State University's Extension Service, said small corn plants are susceptible to damage from extended periods of saturation.

"The weather has caused major challenges for growers trying to apply herbicides and nitrogen in all crops," Larson said. "Applying a herbicide at the wrong time can cause damage and applying too much or too little nitrogen can waste money or reduce yield potential."

Some parts of the state exceeded 13 inches during a four-week period from the end of April to the first part of May. The majority of the rain has fallen in the east-central and northern portions of the state.

"Corn yield potential in these fields most likely will be reduced because of saturated or flooding conditions that have inhibited root growth, stunted vegetative development and promoted crown rot and other diseases that may appear later," Larson said.

The corn specialist said growers will have to watch for signs of crazy top, which generally occurs in fields that were flooded when the corn was less than 6 to 8 inches tall. These plants continue to grow when unaffected plants tassel and begin normal reproductive development.

"Wet conditions also likely caused substantial nitrogen fertilizer loss or delayed timely fertilizer applications," Larson said. "Since successful corn production requires considerable supplemental nitrogen fertilizer, this has caused uncertainty about additional fertilizer and management inputs."

Larson said growers who have not applied their intended nitrogen allotment may be forced to apply it by air if the corn is too tall to permit ground equipment, which would certainly drive up the production costs for this year's crop.

"Base decisions on additional nitrogen applications on the yield potential of the field," he said.

Charlie Stokes, Extension area agronomy agent in Aberdeen, described much of northeast Mississippi's corn as "sad." He said some fields received more than 15 inches of rain the first part of May.

"The majority of the corn is stunted and yellow from the water-logged soils combined with the lack of nitrogen uptake," Stokes said. "At least half the corn acreage has not been side-dressed with nitrogen. Much of the nitrogen in the other fields has been lost due to all the rain. Many fields will be plowed up and replanted in either soybeans, cotton or milo."

Bill Burdine, the area agronomy agent in Houston, said while much of the corn in his area is stunted and yellow, very little will be destroyed and planted to another crop. Most of the damage has not been serious enough for replanting, but yield losses are a certainty.

Across the state in the south Delta, corn growers are looking at significantly different conditions.

"Rainfall in the south Delta was mostly adequate and near-normal for most of May. The corn has not experienced much stress, and in the few areas were it did get too much rain, the fields have recovered pretty well," said John Coccaro, area agronomy agent in Rolling Fork.