The Environmental Protection Agency has approved commercial use of a unique biopesticides that reduces aflatoxin in cottonseed and could mean millions of dollars in added income for cotton producers in Arizona and South Texas for their cottonseed.
EPA's approval of the commercial use of Aspergillus flavus or AF36 also could represent a major breakthrough in reducing aflatoxin in corn, walnuts, almonds and peanuts using the same technology developed in a partnership between the Arizona Cotton Research and Protection Council (ACRPC) and a USDA-ARS plant pathologist, Peter Cotty of the Southern Regional Research Center in New Orleans.
Seed with more than 20 parts per billion aflatoxin cannot be fed to dairy animals and cotton producers in Arizona and South Texas are discounted for up to $25 to $30 per ton below market on their whole cottonseed sales.
More than 100,000 acres of Arizona cotton is affected by aflatoxin each year ad as much as 500,000 acres of South Texas cotton suffers from the same malady.
“Aflatoxin costs our producers $1 million a year,” said Hollis Sullivan, president of Valley Co-op Oil Mill (CALCO) in Harlingen, Texas. Although Cotty is in the research phase of using AF36 on cotton in South Texas, Sullivan said “in time I think this is going to be of great assistance to us. There is a lot of enthusiasm that this is going to work.”
Jeff Nunley, executive director of the South Texas Cotton and Grain Association in Corpus Christi, said successful use of AF36 would represent a major economic breakthrough for not only cotton, but corn production in his area as well.
“The problem with aflatoxin in cotton really hit home in 1999 when Hurricane Brett hit the Texas Gulf Coast. A lot of the cotton was in modules, but we still ended up with high levels of aflatoxin and cottonseed sold only $15 per ton,” said Nunley. “That was devastating.
“That really brought the problem to the forefront. We are excited about working with Dr. Cotty to see if AF36 will work here under our dryland conditions as opposed to irrigated cotton in Arizona,” said Nunley.
Nunley said if aflatoxin can be reduced in cotton, it could have carryover benefits in producing corn, which also can be plagued by aflatoxin. “We had a disastrous corn situation three years ago because of aflatoxin,” said Nunley. Aflatoxin is a highly potent natural carcinogen and feeding animals grain with even minimal levels of it is forbidden by law.
Cotty is testing AF36 on 2,000 acres of South Texas cotton this year. “We are optimistic because it reduced aflatoxin in small cotton plots. Now we have to see if it works in commercial plots this year.”
In Arizona, AF36 has proven to work on up to 20,000 annually over the past several years that the Arizona Cotton Research and Protection Council has been funding Cotty's research.
“It has been a long time coming,” said Pinal County, Ariz., cotton producer Paul “Paco” Ollerton, who is chairman of the Arizona Cotton Research and Protection Council. The council is the registrant for the product and will produce it non-profit at its plant near Phoenix and sell to producers for only $5 per acre.
“From a grower standpoint, the registration is pretty exciting news,” said Ollerton.
The impact of aflatoxin is undeniable. However, it does not occur every year in all fields. “You do not know from one year to the next whether you'll have it, but at $5 per acre for material and $5 to $7 per acre to apply it, it is really a no brainer when you consider the difference between clean and dirty cotton seed can be $25 to $30 per ton.”
There has been no effective conventional fungicides that control Aspergillus flavus or aflatoxin. AF36 is a naturally occurring, non-aflatoxin producing strain of Aspergillus flavus that does not produce aflatoxin. It is applied in sterile wheat seed generally by air at layby. It is applied in a 10-pound per acre product that contains less than .01 pounds per acre active ingredient.
It competitively excludes aflatoxin producers during colonization of the cotton crop. AF36 has also shown to have a carryover effect from one season to another in reducing aflatoxin in specific fields.
ACPRC is gearing up to produce enough AF 36 to treat about 100,000 acres next season.
The development of AF36 has been a collaboration USDA/ARS, ACRPRC, the National Cotton Council, Cotton Incorporated and IR-4. IR-4's mission is work on crop management protection for minor crops and also help minor uses for major crops.