Bugs and weeds are a menace to Texas corn growers. But possibly the biggest battle many Texas farmers face is the aggravation of aflatoxin — the feared contaminant that can destroy the value of a bin-busting crop.
It is the major focus of much research being funded by the Texas Corn Producers Board through the statewide corn checkoff program. Aflatoxin is caused by the fungus Aspergillus flavus. It is spawned by drought and high humidity.
Corn with aflatoxin content above 300 parts per billion cannot be fed to finishing beef cattle. Corn with 20 ppb or more aflatoxin cannot be used for human consumption, immature animals or in a dairy ration. Some foreign grain buyers also turn away corn with minute amounts of aflatoxin.
It causes tens of millions of dollars in losses for Texas growers every year. Dozens of Texas counties had elevated levels of aflatoxin in 2008. In 1998, a drought year in the Midwest, Corn Belt growers suffered more than $280 million in losses from aflatoxin, says Scott Averhoff, a Waxahachie, Texas, grower and TCPB chairman.
TCPB has been a leader in supporting aflatoxin research for years. Specific aflatoxin projects include one which looks at using a biocontrol fungus — that is already EPA-approved for use on cotton — to manage aflatoxin in corn. The study is headed by Peter Cotty, a USDA Agricultural Research Service plant pathologist in Arizona who also works with Texas A&M and other universities.
“The program is intended to allow collection of information from commercial corn fields where atoxigenic strain AF36 is experimentally used in several central and south Texas counties,” says Averhoff. This continuation study is examining findings from 2008 research, which shows beneficial effects of using the AF36 strain. The goal is to obtain a full EPA label for use in corn.
Another aflatoxin-related research study through TCPB is evaluating a clay substance that can absorb and bind aflatoxin in animal feed. Headed by Joe Dixon, professor emeritus in the Texas A&M Department of Soil and Crop Sciences, the project is designed to help assure that a supply of aflatoxin absorbents is sufficient for the job and available to growers.
The absorbents are mined from two bentonite mines in Texas. They have been tested in poultry operations. The absorbents could eventually be used in helping growers and others market infected grain and improve animal performance.
TCPB is also working with Don White, University of Illinois corn breeder, in the development of high yielding commercial hybrids with some form of aflatoxin resistance. White says he hopes to create several commercially usable female corn inbred lines the next several years that could lead to aflatoxin resistance hybrids.
Further research involving breeding corn germplasm to reduce aflatoxin contamination is also receiving TCPB funding. Both yellow and white corn inbreds, developed by using subtropical and tropical germplasm, are being evaluated for aflatoxin resistance as well as agronomic performance. This research is being performed by Texas AgriLife scientists Seth Murray, Wenwi Xu and Kerry Mayfield.
Averhoff says TCPB is part of a new “Center of Excellence” Southern states initiative aimed at aflatoxin control. The initiative includes TCPB, other state corn groups, Texas A&M University, University of Georgia, Auburn University, North Carolina State University and Mississippi State University.
“The program involves biological control and ecology, breeding and genetics for aflatoxin resistance, best management practices and remediation of contaminated grain,” says Averhoff.
“Aflatoxin has just been one of those difficult problems to solve. We have such a regulatory oversight. We want to be in the lead in trying to do something about resolving the issue.”
In other TCPB research programs, the board is also allocating funds for research into several other disease and insect control projects. One involves the search for better management options and economic thresholds for grey leaf spot control.
Grey leaf spot is a new disease seen in the Texas Panhandle. Research is looking at how fungicides can help prevent massive yield loss in infected fields.
The western bean cutworm is another menace that has emerged as a problem for Panhandle growers. The effects of Bt corn lines on the insect are being studied. Flight patterns of the cutworm and southwestern corn borer are also being tested.
Spider mites have been a continual problem for many Texas growers for decades. Research this year will look further at the impact of a new miticide, Acramite, as well as proven miticides, Comite, Onager and Oberon. Mite resistance in corn silage is also being funded by TCPB, along with improved mite sampling and scouting.
TCPB’s involvement with biofuels includes studies in the feed value of distillers grain at regional feedyards. With more ethanol plants in the works for the region, use of wet distillers grain by feedyards is increasing. A TCPB funded study is looking at which levels of WDGs are the most efficient in a feedyard ration.
“TCPB is also part of an education program — Texaspricecheck.com — in conjunction with the Texas Wheat Producers Board and Texas Peanut Producers Board,” says Averhoff. “This Web site is for the media and consumers to help them find the facts about what’s driving the price of food. It is to help dispel the myths about ethanol causing food prices to go up.”
For more information on TCPB research, promotion and market development programs, go to http://www.texascorn.org/.
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