COLLEGE STATION -- If any Texas corn plants survived the hot, dry growing season to produce kernels, chances are the kernels are loaded with aflatoxin, meaning further losses for farmers who attempt to market their crop.
"Two years ago was the worst season that we had seen for aflatoxin, and we had violation rates above 80 percent statewide," said Todd Jones, Office of the Texas State Chemist mycotoxin lab supervisor. "And at this point this year, we seem to be approaching those levels again for Central and South Texas."
Jones said a "violation" is a sample which contains more than 20 parts per billion, the maximum amount allowed in grain for human consumption in products such as tortilla chips and for dairy cattle.
By comparison, the 1997 Texas corn crop -- when the state was not suffering a widespread drought -- had only 20 percent violations, Jones said.
Jones' lab runs about 1,000 regulatory mycotoxin samples a year on various susceptible crops such as corn, sorghum, cottonseed, peanuts and soybeans. Mycotoxins are toxins produced by fungi.
"I would be surprised if 100 percent of the dryland crop isn't over the 20 ppb level from the Rio Grande Valley to the Red River," said Cloyce Coffman of College Station, Texas Agricultural Extension Service agronomist. "There'll be big time money lost on the corn that is harvested."
Aflatoxins are toxic compounds produced in contaminated grains by the fungi Aspergillus flavus and Aspergillus parasiticus, and usually are more prevalent in years of high temperatures during flowering and grain-fill and during drought. Animals that consume high levels of these toxins may develop various health problems, depending on their susceptibility.
Though the U.S. Food and Drug Administration set 20 ppb as the maximum amount allowed in commodities for general market, 300 ppb is allowed for feedlot cattle, 200 ppb for market hogs and 100 ppb for breeding livestock, mature poultry, deer and other wildlife. Commodities with 1,000 ppb or higher must be destroyed. The law allows ammoniation of the affected corn crop with lower aflatoxin- containing crops. Feeds from aflatoxin-containing corn that has been either ammoniated or blended fall into more strict usages and cost producers more money than the crop may be worth, Coffman noted.
Corn and other crops are checked for the toxic compound several times from field to market -- at the grain elevator, at state labs and at the ports before loading to foreign buyers. Jones said that at his lab, many samples are registering at 100 ppb and 200 ppb, several are over 500 ppb and six have topped 1,000 ppb this year.
"The main thing we want to do is assist the marketing channels in trying to keep the corn in suitable uses based on its level of aflatoxin," Coffman said. "There's a lot of scrutiny going on at elevators to determine what the levels are and then try to find a market for it."
He noted that farmers faced a losing battle with aflatoxin due to weather this year. Three conditions likely to stimulate aflatoxin outbreaks all have been present this year: hot, dry days at the time of the year when young corn plants are flowering, kernels damaged by earworms, ruptured seed coats as the kernels dry down for harvest.
The hot, dry days at flowering were the first sign of risk for aflatoxin occurrence in grain crops this season and farmers have no control or management tricks that can ward off such damaging temperatures.
"Aflatoxin molecules are very heat tolerant and stable," Coffman said. "Once the grain has it, it is not likely to break down."
SOIL TOP