For decades, Georgia vegetable farmers relied on the soil fumigant methyl bromide to control weeds, insects and nematodes, but recent changes in environmental regulations have led them to find replacements.

Stanley Culpepper, a weed scientist with the College of Agricultural of Environmental Sciences, has been working to find alternatives to the potentially ozone-damaging pesticide. The challenge has been finding something that is as easy to use and as effective as farmers’ old standby, methyl bromide.

Up until four or five years ago, methyl bromide was also extremely economical and used by nearly every tomato, pepper and eggplant producer in the state.

That changed when the Environmental Protection Agency classified it as harmful to the ozone and began phasing the pesticide out.

UGA and the Georgia Fruit and Vegetable Growers Association were able to secure methyl bromide for Georgia growers through a Critical Use Exemption (CUE) in 2006; but the cost of the fumigant rose dramatically.

“Since 2007, growers have displaced methyl bromide rapidly because effective alternatives have been developed that are far more economical,” Culpepper said.

In fact, vegetable growers have advised Culpepper not to seek a request for methyl bromide use in 2014, due to its high cost and the availability of alternatives.

Finding the right alternatives to methyl bromide has been a challenge for Culpepper, who’s devoted almost 10 years to the research project.

“All of the fumigant systems are very expensive. In general, before we ever plant a crop, we’ve got at least $1,000 an acre invested in the fumigant, the mulch and the drip tape. So No. 1, as a scientist, if you’re going to make a recommendation, it better work,” Culpepper said. “You’ve got to know what you’re doing. You’ve got to have good research and a good team behind you.”

Culpepper and his team are researching four systems to replace methyl bromide on farms that use plasticulture — a planting technique used in commercial vegetable production where black plastic is stretched over planting rows to reduce water loss and block weeds.