Research promising

Aflatoxin remedy may be biological Most peanut producers recognize the importance of reducing or eliminating aflatoxin in their crops. Less clear is how they should go about accomplishing this.

"We need to eliminate aflatoxin," says Joe Dorner, microbiologist with the National Peanut Research Laboratory in Dawson, Ga. "But in the near-term, the best we probably can do is to reduce aflatoxin. This might be possible with the application of biological control technology that we've been working on for the past 13 to 14 years."

This biological control is achieved, he explains, by replacing the strains of aflatoxin found in the soil that make aflatoxin with strains that do not make aflatoxin.

"It's very simple. It's just a matter of taking the A. flavus in the field that makes aflatoxin and replacing it with A. flavus that doesn't make aflatoxin. This strain that doesn't make aflatoxin then dominates the soil environment.

"Whenever you have late-season drought conditions that predispose peanuts to aflatoxin contamination, your peanuts still will be infected by the fungus. However, it'll be a fungus that doesn't make aflatoxin, and the end result will be less aflatoxin in peanuts," says Dorner.

A typical peanut field in the Southeast will be dominated by the toxigenic strain of A. flavus, by about a 20 to one margin over the non-toxigenic strains of aflatoxin, he says.

"Our goal is to try and displace a lot of these toxigenic strains by a preponderance of the non-toxigenic strain. We actually deliver these fungi on grain, such as barley. We make up this formulation in the laboratory, so we can treat several acres of peanuts or other crops.

"We associate the fungus that we want added to the field with the grain. Then, when we apply it to the field, it takes up moisture. The fungus grows and produces spores over the surface of the grain, and those spores are disseminated into the soil. This serves as the inoculum to get the fungus into the field."

Putting this relatively small amount of fungus out on the grain results in a large increase in the amount of fungus, notes Dorner. This allows the competition and displacement to occur, he adds.

"We can deliver this with typical granular application equipment," he says. "We inoculate the soil right around where these peanuts are pegging in the soil.

"Based on the formulation alone, it would cost about $5.80 to put out 20 pounds per acre. Earlier studies have shown that the more material we apply, the better control we'll get. We're in the early stages of talking about commercializing this method.

"The peanut industry has told us we need to do this for about $20 per acre or less. Even at 50 pounds per acre, we still can keep that cost under $20 per acre. Realistically, this is the range we're looking at for having an effective formulation at an affordable price."

Field tests utilizing the 20-pounds-per-acre formulation have resulted in a 92 percent reduction in the amount of aflatoxin in a one and a half acre peanut field, according to Dorner. This was a worst-case field scenario with late-season drought, he says.

Drastic reductions in the amount of toxigenic A. flavus contamination also were seen in storage studies, where peanuts in storage were subjected to high humidity and temperatures to encourage contamination. The treated peanuts showed significantly less contamination than the untreated peanuts, reports Dorner.

"These tests demonstrated the carry-over effect that treating these peanuts out in the field can have in a storage situation where poor conditions exist."

If this technology is to be commercialized, the first step would be an experimental use permit (EUP) issued by the Environmental Protection Agency, says Dorner.

"The EPA might ask questions such as, 'What about the amount of A. flavus in the crop?' Data indicates that we do not increase the overall amount of A. flavus in peanuts with the use of this technology. We're simply replacing the toxigenic strain of aflatoxin."

The EPA also might question the amount of aflatoxin in the environment, he adds. The agency will focus, he says, on whether or not there's a greater exposure to A. flavus as a result of using this biological control method.

"Finally, pathogenicity tests may or may not be required to prove that the strains of A. flavus being used are not more pathogenic to insects or birds than the normal strains of aflatoxin."

The second big step in commercializing this method will be increasing the production of the formulation, says Dorner. "If we are successful in obtaining an EUP, we'll need to produce an amount of the formulation necessary to cover the acreage allowed under the experimental use permit."

Safety should be of major concern when working cattle. Each year many beef producers are injured while working cattle.

There's always an element of danger when you are working with animals that are bigger and stronger than you are. And animals, when placed in unfamiliar surroundings and restrained, become fearful and instinctively try to get away.

Animals become more unsettled as they feel pain, such as that from a vaccination. This causes the animal to become even more unpredictable and dangerous.

To reduce the risks of injury, be sure that the cattle-handling facility is in good working condition; Broken boards and improperly working mechanical parts cause situations to develop that can injure either the producer or animal.

Be sure that all people helping work the animals know how to handle cattle and how the equipment works. You have to act smarter than the animals you are treating and be able to anticipate problems before they occur.

When several people are working cattle, each should take a position at the chute and perform the same practices on each animal. Doing this reduces the possibility of failing to perform a practice and the risk of workers bumping into each other. Be sure that each person is aware of the location of all the other workers and that they stay clear of all moving parts and objects.

Cull animals that are high spirited and excitable. These animals are dangerous to handle and increase the risk of injury to you.

Years of experience don't insure that you won't receive an injury. Always be aware that something unexpected could occur. Working cattle is a dangerous job. However, you can reduce the risks by practicing safety all the time.

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