Information Possibly Outdated
The information presented on this page was originally released on June 1, 2001. It may not be outdated, but please search our site for more current information. If you plan to quote or reference this information in a publication, please check with the Extension specialist or author before proceeding.
Sporadic rains cause problems for corn
MISSISSIPPI STATE -- Dry conditions in April and May, especially in the Delta, played havoc with Mississippi's corn crop this spring, leaving the root systems confounded about which way to go.
Erick Larson, corn specialist with Mississippi State University's Extension Service, said wet conditions delayed planting some, but most of the crop was in the ground by the end of April.
"Recent rain has relieved dry conditions in north Mississippi, but it is still relatively dry south of Highway 82," Larson said. "Early drought-stress is not that serious in terms of reducing yield potential, but it reduces the moisture reserves in the soil, which corn typically relies on during droughty parts of the summer."
Larson said corn's critical moisture needs begin in early June in the tasseling and pollination stages. Moisture during the four weeks after tasseling is extremely important for high corn yield.
Without sufficient moisture, the crop has been fighting rootless corn syndrome, an abnormal problem caused primarily by shallow planting or planting into too moist soil.
"Shallow planting forces the primary root system above the soil surface, exposing it to several factors that can impede root development," Larson said. "In too wet soil, the planter compacts the sides of the seed furrow it makes when it places seed in the ground. Dry weather causes the seed furrow to open up, which exposes the primary roots. The exposed roots have a hard time penetrating the soil and also can be impeded by insect or herbicide problems."
Both problems can be solved with adequate rainfall or irrigation.
John Coccaro, Sharkey County Extension agent, said plants in that area faced rootless corn syndrome as the weather turned dry when corn was in the three- to five-leaf stage.
"Plants got top heavy and fell over when their primary root systems couldn't get established," Coccaro said. "It appeared in some cases that the stand was being thinned to a critically low level, but I think most recovered with early irrigation or rainfall that came before it was too late."
Farmers need rains to continue as corn in the Sharkey area is at a critical growth stage.
"We're right on the verge of the corn plant shifting gears and finishing the vegetative growth and starting to tassel, pollinate and develop ears," Coccaro said. "It's critical that farmers do a real good job watering where they can irrigate."
"You'd like to have a nice reservoir of moisture that the corn can rely on when it's using a lot of water and is very sensitive to stress, especially for dryland production," Larson said.
Recent rains have helped meet moisture needs, but they must continue because temperatures and evaporation tend to increase along with the plant's water demand.
A few insect problems surfaced, with cutworms early on and some unusual problems with sugar cane beetles. Chinch bugs infestations were spotted by late May in many fields.
"You have to treat for most of those insects at planting time," Larson said. "If farmers put out an insecticide at planting, they were OK, but if they didn't treat, they did have a big problem."
MSU agricultural economists reported the value of last year's corn crop at $73.2 million, a 0.8 percent increase over 1999. Mississippi corn growers are expected to plant 400,000 acres, about 2 percent fewer than last year.