The biggest drawback to the late planting strategy, Heiniger says, is whether the crop will get some rainfall in the hottest months. If you go totally dry in July, it will set the corn back so much it will be shorter and less productive when the rains do come, he explains.

Even if it’s hot and dry when corn is planted in July, the grower should consider using a starter fertilizer. The crop has to come out of the ground fast and begin to grow-off fast, because there are almost certainly going to be some periods of hot dry weather in the first few weeks after planting, he adds.

“There are clearly some risks to planting corn in July in our part of the world, but the past three years growers who have tried it have done well,” the North Carolina State specialist says.

The theory behind planting late to avoid the heat has some merits.

“When it’s cool at tassling and cool at grain fill, then you get heavier kernel set. There are some real possibilities to planting corn late, but we just haven’t explored these options, because we didn’t have Bt corn and planting late and fighting insects just wasn’t an option,” Heiniger says.

“Bt corn has changed the rules. Plus, growers now have a much wider array of hybrid varieties that can mature anywhere from 90-120 days.

“Growers are not going to break any yield records because the crop is compressed into fewer days, grows faster and gets less light intersects than a conventionally planted crop,” he adds.

“If I was planting corn in late June or July, following wheat, I wouldn’t go with one of the shorter maturing hybrids. I’d probably plant a 105-112 day corn. Growers have more time than they think, and the farmers I know who have planted behind wheat have not had a problem getting corn to mature prior to frost,” Heiniger says.

The corn hybrids with the shorter maturity periods were primarily bred for regions of the country that have a severely depressed growing season. In general, these varieties haven’t performed well in the Southeast, and we have 105-112 day hybrids that are bred for our part of the country and these varieties do have time to mature in the Southeast, he adds

Another option is to plant corn after corn, which has allowed growers to produce three crops in two years.

The can happen when corn is planted in late March, and is followed by a second crop of corn planted in early July, which is followed by wheat planted in November. With irrigation and some timely planting and harvesting, a few growers have done well using this planting system.

Having irrigation is a must for such a planting system, but Heiniger says growing 200 bushels of corn per acre and 100 bushels of wheat seems like a much better option than risking production of either crop by squeezing in a second crop of corn.

However, maximizing use of expensive irrigation equipment is another factor to consider, and in some cases the extra corn crop may produce enough more profit to pay for an irrigation rig.

Year after year corn will respond better to irrigation than any other crop. The new varieties we have are adapted to respond better to a uniform supply of water.

“We used to talk about a 15-20 bushel per acre increase on irrigated versus non-irrigated corn. Now, we talk about 40-50 bushels more, and sometimes a lot more than that,” Heiniger says.

(For those interested in the concept of late-planted corn, a good read can be found at Weather projection: Late-planted corn might be best).

rroberson@farmpress.com