Sun May Rise As Methyl Bromide Sets

By Judy McBride
October 14, 1999

Some Florida vegetable growers are getting better yields in winter crops by relying on the sun instead of methyl bromide. Researchers are seeking alternatives to this fumigant, scheduled to be discontinued in 2005.

Agricultural Research Service plant pathologist Daniel O. Chellemi in Fort Pierce, Fla., has enlisted several growers to test soil solarization. This means covering the soil under clear plastic for at least 6 weeks during summer to “cook” weed seeds, diseases and some nematodes. Before the winter crop is planted, the plastic is painted white to cool the soil enough for tender roots.

Last fall, yields from solarized fields ranged from 96 percent to 123 percent of yields from methyl bromide-treated fields on three commercial farms. The pepper field yielding 123 percent had been deep-disked before solarization to break up stubble and bring nematodes to the surface so heat would destroy them.

On another farm, two solarized pepper fields yielded better than methyl bromide--118 and 104 percent. Both had been "beefed up" with a biosolids compost. It was the second year of solarization for the field yielding 104 percent and third year for the field yielding 118 percent. This means solarization may gradually raise yields, according to Chellemi.

For organic grower Kevin O'Dare of Vero Beach, Fla., solarization saved his business. Last year, his second year of solarization, production rose 30 percent, labor dropped 75 percent--and profits jumped 100 percent.

Solarization has drawbacks: It works only for fall planting--half the crop in the deep South. It doesn't adequately control all pests. And growers must start preparing field beds at least 6 weeks before planting--posing logistic problems for large operations. Read more about solarization in the October issue of Agricultural Research magazine, online at:

/is/AR/archive/oct99/sun1099.htm

ARS is the USDA’s chief scientific agency.

Scientific contact: Scientific contact: Daniel O. Chellemi, ARS U.S. Horticultural Research Laboratory, 2199 South Rock Road, Ft. Pierce, FL, 34945, phone (561) 467-3877, fax (561) 460-3652, dano@sunet.net.