MISSISSIPPI STATE – Heavy rains, limited sunshine and high humidity in mid-September are threatening to damage the state’s major row crops unless dry weather returns soon to allow harvest to finish.

Soybeans are most at risk now because the bulk of the state’s crop was ready or almost ready for harvest when wet weather rolled into the state mid month.

Trey Koger, soybean specialist with the Mississippi State University Extension Service, said the crop is only about 25 percent harvested.

“This rain is not doing any good for about 60 percent of the state’s soybean acreage,” Koger said. “About 20 percent of the crop is benefitting because it was planted late.”

How well the crop waiting for harvest fares depends partly on how diligent producers were during the growing season.

“If they did a good job managing the crop through the season, the negative impacts of this weather will be less,” Koger said. “The cool, wet weather is less harmful to the crop standing in the field than hot, wet weather, which causes more seed rot and allows more mold to form.”

It is difficult to get an accurate estimate, but Koger said the portion of the crop already harvested has taken losses from seed rot-related issues that may exceed half a million dollars.

Nathan Buehring, Extension rice specialist, said rice was about 25 percent harvested when the latest rains began. Rice ready for harvest has a stalk that is not as strong as it is when the plant is greener and growing. Heavy rains can lodge the plant, or knock these stalks to the ground.

“Lodging is the biggest issue we’re going to have with all the rain,” Buehring said. “This increases the cost of harvest and contributes to a slight yield loss.”

Buehring said rice does not usually face the seed rot issues other grain crops face, so soybean harvest will take precedence over rice harvest when the weather clears.

Darrin Dodds, Extension cotton specialist, said rains are beginning to hurt the state’s cotton crop and are preventing some farmers from applying the defoliating chemicals needed 10 days to two weeks before cotton is picked.

“Some folks are prepared to start defoliating, but the rain is holding them up,” Dodds said. “If it keeps raining and stays relatively warm and muggy, we run the risk of seeing more hard lock and boll rot. In addition, recent heavy rainfall in selected areas of the state has led to seeds sprouting in the bolls that were already open or in bolls in the field that had already been defoliated.”

Dodds said cotton harvest will probably be well under way in early to mid-October, which is two to four weeks later than normal.

Erick Larson, Extension corn specialist, said the corn crop was about 75 percent harvested when the recent round of rains began. Corn fields in the south Delta and southern part of the state are mostly harvested while the northeastern part of the state is somewhat behind schedule.

“The corn is mature, but once it reaches maturity, it is at a relatively high moisture content that is not fit for safe storage in grain bins. Farmers let it dry in the fields until it gets to a level that is much more practical for on-farm and commercial storage,” Larson said. “The rainfall we’ve had since the first of August has slowed down that whole process and harvest progress.”

He said corn is a hardy crop and can stand wet weather in the field better than most. The biggest problem with storms when corn is waiting for harvest is the threat of winds that can blow down the stalks.

“Stalks that get blown down make combine harvest very difficult and tedious. Lodging can substantially increase loss of corn ears and reduce grain quality as well,” Larson said.