As the supply of methyl bromide shrinks, the price continues to rise.
“Methyl bromide is going to be around for the next three to five years, but it’s going to be around at much reduced levels,” says Mike Aerts, assistant director of the Florida Fruit and Vegetable Association’s environmental and pest management division in Maitland. “Transition will be the word here. Growers need to have strategies in place that they can fall back on if they can’t get
bromide or all of the bromide they need.”
The EPA also recommends growers use an emission-minimization or barrier film, Aerts says.
Putting the newcomer to the test
In field trials conducted at the U.S. Horticultural Research Laboratory in Fort Pierce, Chellemi is comparing Midas applied under metalized or virtually impenetrable films with the industry standard low-density polyethylene mulch.
Plastic mulch permeability to chemical fumigants is characterized by the amount of fumigant that can pass through a section of film over time. It is reported as grams of fumigant per square meter of film per hour.
In laboratory tests involving an initial concentration of 1,000 parts per million methyl bromide under the film, Chellemi says typical permeability measurements range from about 120 grams per square meter per hour for low-density polyethylene to 13 grams for metalized film and 0.2 grams for VIF.
Although he says growers may not need to go to the extreme of using VIF, he says they need to consider improved barriers because of increasing environmental concerns.
Chellemi’s trial also involves three rates of Midas—180 pounds, 150 pounds and 120 pounds per treated acre. Each plot is 75 feet long, and each treatment is replicated four times.
“We want to see how low a rate we can use and still get [pest] control,” he says.
Pacific Ag Research of San Luis Obispo, Calif., used the patented Symmetry machine to apply the fumigant.
Once the beds were fumigated and plastic applied, peppers and tomatoes were planted. Throughout the trial, Chellemi and his technician, Nick Rotindo, will rate weed control in the plots.
“Unfortunately, there was some variability in nutsedge control with the lowest rate under the VIF,” Chellemi says about early weed counts.
They hope to be able to harvest a crop and evaluate fruit yield and quality.
How do alternatives pencil out?
Arysta recommends 150 pounds of product per treated acre when used with metalized film or VIF, Allan says. In fields with 36-inch beds and 6-foot centers, Chellemi says growers actually will apply 75 pounds of Midas per acre because they only treat the beds, not the row middles.