Rain delays no cause for panic -- yet

“We’re at a dead halt right now, with about 10 percent of the state’s corn crop in the ground. There was a substantial amount of corn planted in the southern Delta the first week of March, but in the two-week period since then the rainfall has prevented any further planting,” says Extension corn specialist Erick Larson at Mississippi State University in Starkville.

When the ground does dry up enough to get a tractor back in the field, Larson says, there will still be ample time to plant the state’s 2002 corn crop. “It’s not going to be too late by any means. The optimum planting dates for the South Delta last until April 10. Mid-Delta growers can safely plant until about April 20, and the optimum planting dates run through April 25 for corn growers in the North Delta, or north of Bolivar County,” he says.

In Mississippi, state corn planting guidelines call for a soil temperature of 55 degrees Fahrenheit at a two-inch depth, or 50 degrees Fahrenheit at a soil depth of six inches. Corn produces its highest yields when planted within four to five weeks after the soil temperature is warm enough for germination, the guidelines state.

“Extraordinarily early planting enhances mid-season maturity very little because corn growth rate is correlated to temperature and heat unit accumulation is historically very low during early March,” says Larson. “Planting before the soil temperature is warm enough for germination greatly increases the potential for stand failure.”

In Louisiana, state guidelines set March 15 through March 25 as the ideal planting time for corn. To improve corn root development, the LSU AgCenter also recommends delaying corn planting until the soil temperature at 7 a.m. is at least 55 degrees Fahrenheit. “Be sure to test the soil temperature in those spots of the field that tend to give you problems. Chances are, those problem areas are going to be the colder areas of the field.

Corn germination so far in 2002 has been extremely slow, according to Larson, due to low soil temperatures. “Soil temperatures remained below our minimum for corn germination through the first week of March,” he says.

Because Mid-South corn growers encounter wet weather around planting time almost every year, most Delta growers incorporate some type of stale seedbed into their production system. “Corn tillage systems in Mississippi, for the most part, include only a bare minimum amount of tillage and little, or no, springtime seedbed preparation,” Larson says. “Wet weather during the spring typically reduces the amount of time available for field work because a timely planting date is very important to the success of your entire corn production system.”

In years like 2002 though, saturated soil conditions can cause potential stand failure problems because of either seed rot, or seedlings simply drowning out because of the lack of aeration in the soil.

The most significant thing a grower can do to prevent some of the problems associated with wet conditions is to plant on raised beds, Larson says. However, he says, “Because that is a fairly intensive tillage practice, and time is limited at this point, it is unlikely producers could prepare raised beds and still plant in a timely manner this spring.”

For those growers planting Bt corn in 2002, Larson reminds them of the refuge requirements which mandate they plant no more than 50 percent of their acreage in Bt hybrids containing YieldGard. In all cotton growing areas, the non-Bt refuge acreage must be planted within one-half mile of the Bt corn.

“Bt corn prevents damage from Southwestern and European corn borers, and we haven’t had a significant problem with those pests since 1998. Because of that, the percentage of acreage planted to Bt hybrids in Mississippi hasn’t changed significantly in the past four years,” he says. “In addition, one of the things limiting Bt use is the expense of the technology. Bt corn adds $8 to $10 per acre to your corn production system expenses, and if the pest isn’t a significant problem you may not recover that input cost.”

Overall, corn acreage in Mississippi is predicted to be up significantly in 2002. Mississippi farmers planted 400,000 acres of corn in 2001, and most estimates are indicating that figure will be somewhere near 600,000 acres this year. That’s a 40 to 50 percent increase in acreage, and it’s primarily coming out of cotton.

In the last 20 years, the average corn yield for the state of Mississippi has gone from 62 bushels per acre to 130 bushels per acre in 2001. “Our corn yield levels are increasing more rapidly than any other crop planted in the state. We have more than doubled our corn yield level in the past 20 years, and we’ve improved our state yield average by more than 11 percent in just the last year,” Larson says.

“Production practices and inputs are changing fairly rapidly because of both new technology like enhanced hybrids and other inputs, but we are also changing some of our management practices like fertility levels and plant populations in order to keep up with this increased yield potential,” he says.

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