Purdue experts offer options for replanting flooded cornfields
Farmers with flooded cornfields have many considerations to make if they want to replant another crop this year, according to Purdue University agricultural experts.
Farmers in Southern Indiana may try to replant corn up until the end of this month, according to Bob Nielsen, Purdue Extension corn specialist. "Most of us believe, however, that corn planted in late June will yield only about 50 percent of that planted during normal periods," he said.
Because of the lateness of the season, farmers may want to switch to soybeans that generally may be planted later than corn. However, a potential problem is that herbicides that were applied to corn may inhibit soybean growth. "The only herbicides labeled for use in corn which would allow replanting soybeans immediately are Prowl and Python," said Bill Johnson, Purdue Extension weed specialist.
All other soil-applied corn herbicides require several months before soybeans can be planted in treated fields. Most of the post-emergence herbicides have shorter rotational intervals, but would still require a couple of weeks before soybean planting, he said.
Farmers looking for another possibility may choose sorghum, said Nielsen. In southern Indiana, sorghum may be planted as late as the end of June or early July. "Grain sorghum is an acceptable crop alternative to corn for hog and cattle producers," Nielsen said. "However, because sorghum is not widely-grown in Indiana, the availability of sorghum seed may be limited."
Nielsen also said farmers who have never grown sorghum before will need to learn the "ins and outs" of this crop. "For example, field dry-down of sorghum can be slow and unpredictable," he said.
Another option may be to plant a summer forage crop such as pearl or German millet, sudangrass, sorghum-sudangrass or perhaps oats later in the summer, said Keith Johnson, Purdue Extension forage specialist. "This might be a consideration for row-crop farmers who also have livestock," he said.
Regardless of the crop selected, insured farmers must check with the crop insurance company to make sure that it will release the flood-damaged area for replanting, said Purdue agricultural economist George Patrick.
"It may be that the company requires the producer to leave some of the original crop in the field to mature, as a way to help determine the exact loss associated with the flood damage," Patrick said.
Growers that are planning on replanting have a number of options to consider.
“The first thing to consider is how to get rid of the existing stand,” Johnson said. “If a grower planted Roundup Ready or Liberty Link corn, their options for removing the existing stand are somewhat limited.
“Options include tillage or the use of the herbicides Select, Gramoxone or Liberty. There are really four options here and tillage is far and away the best option, but due to high fuel costs and the desire to remain in no-till, it’s not for every grower. The use of Gramoxone and Liberty can be somewhat variable; as the crop gets bigger the herbicides ability to control existing corn is more variable. My concern with Select is that it has a rotational interval of six days. ”
Corn that is not Roundup Ready can be controlled by treating it with Roundup Ready, Johnson said.
More information on replanting options is available online at http://www.agry.purdue.edu/ext/corn/news/articles.08/FloodingReplant-0611.html .