MOBILE, Ala. (AP) – Auburn University researchers say they’ve developed a substitute pesticide for methyl bromide, a widely used pest, weed and plant disease killer that’s being phased out because it damages the ozone.

For many farm operations, finding a substitute is a matter of economic survival because of their years of dependence on methyl bromide. For the pesticide industry, the right substitute could boost corporate profits as debate swirls over one of the chief environmental issues in global agriculture, according to government officials and researchers.

Despite an outcry from farmers who rely on it, particularly in California and Florida, methyl bromide production is scheduled to be phased out in the United States by Jan. 1, 2005, under the 1987 United Nations Montreal treaty to reduce ozone-depleting substances.

Methyl bromide users argue there’s no substitute as potent as this highly toxic gas that is injected into the ground before planting. It can be fatal to humans in large doses and causes a range of neurological problems at lower concentrations.

Under the treaty, developed nations this year are supposed to reduce their methyl bromide usage by 70 percent below 1991 levels. The phase-out process began with a 25 percent reduction in 1999. U.S. farmers were using an estimated 21,000 tons annually to fumigate soil before planting crops.

While farmers have been preparing for the phase-out for several years, the 2005 deadline increases pressure to find an acceptable alternative product.

Plant pathologist Rodrigo Rodriguez-Kabana, the Auburn University professor who believes he has a developed a breakthrough product – SEP-100, a liquid formula of sodium azide – said it significantly out-performs methyl bromide in controlling weeds, diseases and harmful, root-eating nematodes.

SEP-100 is delivered by drip irrigation under plastic sheeting without spraying or release into the atmosphere, he said in a telephone interview. It’s been field-tested on crops in Auburn and Brewton in south Alabama.

In medicine, sodium azide has been used as a hypotensor to reduce blood pressure in emergency situations, he said. “So, there is quite a lot of medical knowledge available on the compound,” he said.

Much of Rodriguez-Kabana’s current research at the Alabama Agricultural Experiment Station, conducted with colleagues Elizabeth Guertal, Robert H. Walker and David H. Teem, has been funded by the nation’s sole sodium azide manufacturer, American Pacific, or AmPac, which is trying to register SEP-100 with the U.S. Environmental Protection Agency.

Rodriguez-Kabana said the methyl bromide replacement could be on the market as early as the 2004 growing season for a limited number of crops. If the U.S. Patent Office grants a patent on the sodium azide formula, Auburn University would profit from it.

Auburn has applied for two patents on sodium azide: one for the new liquid formulation of the chemical, which previously was marketed only in granular form, and the other for the chemical’s soil-enhancement properties.

“As sodium azide decomposes in the soil, it breaks down into fertilizer and leaves the soil healthier than it was before the sodium azide was applied,” Rodriguez-Kabana said.

Also, he said, while methyl bromide kills all nematodes and insects, both “good” and “bad” in the soil, sodium azide does not harm beneficial nematodes and insects.

About 10-15 different products are being discussed as alternatives for methyl bromide.

“The most successful of them are always mixtures of two or more individual compounds or combination treatments,” the Auburn professor said. “They do not come up to the performance of methyl bromide and certainly not that of azide. Moreover, there are serious problems with some of these mixtures.”

The EPA has published three volumes of case studies which describe potential alternatives to the use of methyl bromide. Each volume contains ten case studies that examine alternatives that manage pests that are currently controlled by methyl bromide.

The EPA also says five alternatives have been registered in the last four years, with additional alternatives in the registration pipeline that may be approved and become commercially available.

That would reduce the critical need for methyl bromide in 2005 and beyond, according to EPA.

Nevertheless, supporters of methyl bromide use, including the American Farm Bureau Federation, haven’t given up on easing the production ban, pressuring Congress and the Bush administration to intervene, with some effect. The United States has made a request to the United Nations for a two-year exemption to the methyl bromide phaseout, beginning in 2005.

The request could be considered in November at a meeting in San Diego on the treaty demands. Rodriguez-Kabana said he plans to discuss his research at that meeting.

Rebeckah Freeman, a Farm Bureau spokesman on the congressional front, said she was unaware of the Auburn product being widely known or discussed.

Other products, she said, have worked for many, but cost too much to use; worked, but no manufacturer could justify the cost of taking it through registration with EPA; or worked for some but were too impractical to use because of additional equipment costs.

Some product worked for several years until a resistance developed, she said, in which case methyl bromide had to be kept in the “cycle of treatment.”

As the debate continues and farmers work on crop budgets for the years ahead, the price of methyl bromide, once below $1 a pound, has reached $2.50 or more a pound because of the phase-out of the product. That’s about $500-$600 an acre at current prices.

Agriculture groups eligible for “critical use” exemptions to the phase-out can apply to EPA for an exemption, giving proof they have no alternative to methyl bromide use.

Top agriculture officials contend the phase-out of methyl bromide will lead to increased imports from China and Third World countries that can continue to use methyl bromide long after the U.S. and other advance nations have halted its use. However, most industrialized nations will prohibit or already do prohibit the importation of food stuffs produced with methyl bromide.

Strawberry and vegetable grower Greg Burris, who farms 100 acres in coastal Baldwin County, Ala., said the impact of the loss of methyl bromide won’t gain the public’s full attention until politicians who like to golf see a difference in their greens. Methyl bromide is also used on golf courses and by sod farms.

“Just go tell the politicians, “Sorry, the golf course isn’t open today.’ Politicians have time to play golf,” said Burris. “It’s not just the poor little old farmer that’s going to be affected.”

On the Net:

www.epa.gov/pesticides

AP-ES-07-20-03 1222EDT