Louisiana:

Northeast Louisiana Crops Look Good - If Only it Will Rain

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By Linda Foster Benedict

LSU AgCenter Communications

  ST. JOSEPH, Louisiana (June 24, 2009) – So far, the chief crops in northeast Louisiana – cotton, corn and soybeans – are looking good, according to the LSU AgCenter specialists who spoke at a field day at the Northeast Research Station here, but they need rain.

 “We need rain – especially the corn,” said Don Boquet, an LSU AgCenter cotton specialist at the Northeast Research Station and one of the speakers at the station’s annual field day June 17. “Corn is at the stage where it’s forming ears and tassling.”

 For corn, the hot and dry conditions can lead to problems with aflatoxin, a toxin produced by a fungus called Aspergillus flavus. If the level of this toxin gets too high, it can cause the corn to be rejected for market, resulting in huge losses for farmers.

 Aspergillus flavus is a naturally occurring fungus found in soil across the southeastern United States and normally harmless unless conditions – such as heat and drought – trigger the production of aflatoxin, which is a cancer-causing toxin.

 “We haven’t had a serious statewide outbreak of aflatoxin in corn since 1998,” said John Russin, LSU AgCenter associate vice chancellor for research. “Aflatoxin is a chronic problem – always on the minds of Louisiana corn producers.”

LSU AgCenter researchers are working on ways to minimize aflatoxin production. One way is through biological control using nontoxin-producing strains of the Aspergillus flavus fungus, said Ken Damann, an LSU AgCenter researcher in the Department of Plant Pathology and Crop Physiology.

 “These strains out-compete the toxin-producing strains, leaving the corn safe,” Damann said.

 After nearly five years of research, Damann is down to four nontoxin-producing strains that are aggressive and essentially outcompete the aflatoxin-producing strains. He hopes to have a product developed farmers can use in their fields in the next few years.

 “Our goal is a product that’s convenient and economical for the farmer to apply in the field and prevent aflatoxin production,” he said. “We’re getting closer.”

 LSU AgCenter researchers also are testing drought-resistant corn hybrids of at the Northeast Station to see how resistant they are to aflatoxin production and how well they grow under Louisiana conditions, Damann said.

 To help prevent dry weather from causing crop losses, a growing number of farmers have installed irrigation systems in their fields, said Carol Pinnell-Alison, county agent in Franklin Parish, which is in the center of the northeast quadrant of the state.

 “About 80 percent of the farmers in Franklin Parish irrigate,” she said.

 Most of the newer systems are in-furrow systems, which require land-leveling and the installation of plastic tubes from which the water trickles along the edges of the field. The other type of irrigation involves sprinkler systems, which are on wheels and roll along the field to where they’re needed. They are not as efficient and don’t do as thorough a job of watering – but are less expensive to install because no land-leveling is required.

 The dry conditions work in favor of preventing fungus-induced diseases in soybeans, such as Asian soybean rust, according to Boyd Padgett, LSU AgCenter plant pathologist and another speaker at the field day. Asian soybean rust can potentially destroy soybean fields because it can spread so quickly.

 “We’ve found Asian soybean rust in kudzu and in some soybeans this year,” Padgett said. “But it’s been confined to the coastal parishes. Dry weather helps prevent the spread.”

 In Louisiana, kudzu acts as a year-round host plant for the fungus that causes the disease.

 If the rust disease would start to move north, the LSU AgCenter agents would recommend applying fungicides to soybean fields as a preventative. Fungicides are among the most expensive chemicals to use in a farming operation so farmers like to avoid them, and the LSU AgCenter conducts research on how, when and if to use fungicides.

 “If soybean producers don’t irrigate, there’s no need to spend money on fungicides,” Padgett said. “The conditions right now are just too dry for fungus problems.”

 Farmers in Arkansas, Mississippi and Louisiana can get the latest information about Asian soybean rust by calling a hotline – 866-641-1847.

 “We update this regularly so people can find out how close or far away the rust is from their fields,” Padgett said.

 Another area of concern for farmers, which was addressed at the field day, is herbicide drift. This has become a problem because when farmers spray herbicide-resistant crops, some of the chemical can drift onto crops not herbicide-resistant and cause yield losses.

 “This has become a problem for some rice farmers in the past few years,” said Bill Williams, LSU AgCenter extension weed scientist. “Herbicide drifts from some of the soybean fields and hurts their rice yields.”

 The drift happens because of what’s known as the inversion factor. Even though the farmers spray when there’s no wind, the herbicide can still spread over unwanted areas. If there’s no wind, the warmer air is trapped beneath cooler air, keeping the excess herbicide close to the ground. Then with any air movement, the herbicide can spread over an area two to five miles – even 10 miles – away.

 “It’s better to apply herbicides when there’s a little wind so any excess will rise and evaporate in the atmosphere,” Williams said.

 Another weed problem addressed at the field day involves stray crops showing up in the wrong fields – for example, stray corn plants in a soybean field or soybean plants in a cotton field.

 “These are known as volunteer weeds,” said Donnie Miller, research coordinator at the Northeast Station and a weed scientist. “A weed is a plant out of place so a corn plant becomes a weed if it’s growing in a cotton field.”

 These volunteer weeds compete with the crop for nutrients and water, and they can also interfere with harvest.

Miller conducts research on these volunteer weeds and has developed recommendations to avoid and control this problem.

 Agriculture has a billion-dollar impact in the northeast Louisiana economy, and the LSU AgCenter’s Northeast Research Station was established to serve this area with the latest research, Miller said.

 “We want to help the farmers reduce their input costs and maximize their profits,” Miller said. “We conduct crop production research right here in their backyard, under their conditions. We’re accessible to answer their questions. We have long-term projects, and we have the flexibility to help solve problems as soon as they arise.”