Some Florida vegetable growers are getting better yields in winter crops by relying on the sun instead of methyl bromide. This is good news for those seeking alternatives to this fumigant, which is scheduled to be discontinued in 2005.

Subject:   ARE SAFE UNREGISTERED ALTERNATIVES "LEGAL" IN CALIFORNIA?
Date:       Thu, 21 Oct 1999 08:14:37 -0400
From:     Stephen Tvedten <steve@getipm.com>
Organization:     Get Set Inc. (www.getipm.com)
To:     Lyndon Hawkins <hawkins@empm.cdpr.ca.gov>
 

Lyndon, I thought you might like to see another effective, safe alternative to your "registered" poisons - I worked in Ft. Pierce several years ago and detailed this safe control and several others to several growers there then.

Using the Sun as an Alternative to Methyl Bromide- EarthVision Reports -  10/19/99

FORT PIERCE, FL, October 19, 1999 - Some Florida vegetable growers are getting better yields in winter crops by relying on the sun instead of methyl bromide. This is good news for those seeking alternatives to this fumigant, which is scheduled to be discontinued in 2005.

Plant pathologist Daniel O. Chellemi of the USDA's Agricultural Research Service (ARS) has enlisted several growers to test a method called soil solarization. This method entails covering the soil with 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.

According to the ARS, yields from solarized fields last fall ranged from 96 percent to 123 percent of yields when compared to methyl bromide-treated fields on three commercial farms. The pepper field that generated the 123 percent yield had been deep-disked before solarization to break up stubble and bring nematodes to the surface so the heat would destroy them. Another pepper field on the same farm, which had been shallow-disked, yielded 106 percent as much as a comparable field treated with methyl bromide. Where no disking was done before solarization, yields were virtually the same as those achieved with methyl bromide, at 99 percent.

"Although we're not getting the residual benefits from methyl bromide fumigation anymore, yields are actually going up under soil solarization," says Chellemi.

He suspects that the revival of beneficial microorganisms, which gives the soil a better balance, is behind the increased yields.

Although solarization has its drawbacks, when methyl bromide use is no longer permitted, farmers will be forced to look at alternatives. Some of the drawbacks include the method working only for fall planting (about half the crop in the deep South) and the inability to control all pests adequately.  So, in order to use solarization effectively, an integrated pest management (IPM) approach is required. This can include chemicals and changes in farming practices, depending on which weeds, diseases, or insects lie waiting in a given field.

"Growers are reluctant to adopt IPM to control soilborne pests; they haven't needed it for 30 years.IPM is a niche that will be filled by other types of professionals," Chellemi says, noting that California now has groups of pest specialists who know the least toxic controls to use for specific pests.

But for organic grower Kevin O'Dare of Vero Beach, Florida, solarization saved his business. "I can't say enough for it," O'Dare says.

Purple nutsedge, a tough turf weed that is even hard to control on conventional farms with chemicals, was close to taking over the 10 acres of Osceola Organic Farm, he says. Last year, his second year of solarization, "our production was up 30 percent, our labor was down 75 percent, and our profits were up 100 percent," says O'Dare.

Now in his eighth year of testing soil solarization, Chellemi says, "There's no doubt in my mind that it has a place. It's not a universal replacement for methyl bromide, but it is a viable option for farmers who are willing to explore it.

"We want to tell growers that they're not going to have a widespread crop failure if they use soil solarization."

Lyndon, are you going to register the plastic or the sun as a pesticide before you allow this technique to be "legally" used to control pests in California?

Respectfully,  Steve.
 
 

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