Jordanian Farmers Adopt MeBr Alternatives

In the Jordan Valley, a deep rift valley where the Jordan River flows, temperatures can reach 110^oF in the summer months. But Jordanian farmers can use this to their advantage, according to Volkmar Hasse. He is with the Deutsche Gesellschaft fuer Technische Zusammenarbeit, which gives technical help to developing countries on behalf of the German Federal Ministry for Economic Cooperation and Development.

Through a bilateral Jordanian-German technical cooperation project, Hasse and a team of colleagues are introducing integrated pest management (IPM) to Jordanian farmers. He is also working on a project—funded by the German government through the Multilateral Fund—to help these farmers adopt methyl bromide alternatives.

"Our cooperators include pioneer farmers, several government institutions, nongovernment organizations, private companies, and local universities. Since 1995, the IPM project has helped us develop methods to wean Jordanian farmers from misusing pesticides in their fields. We're now trying to use these methods to convince methyl bromide users to convert to cheaper, more environmentally friendly alternatives," Hasse reports.

The Jordan Valley lends itself well to the use of soil solarization to eliminate soilborne pathogens, Hasse contends. Soil solarization is the technology whereby a grower covers the soil with sheets of plastic to trap the sun's heat and warm the moistened soil in order to control soilborne pathogens. Since 1981, Walid Abu Gharbieh and colleagues from the University of Jordan have been researching soil solarization as a preplant treatment to control soilborne pathogens of greenhouse and open field vegetables in the Jordan Valley. "Their efforts didn't stop at academic research," Hasse points out. "Gradually over the years, hundreds of farmers adopted solarization after seeing the successful trials."

Was it a hard task to convince growers to switch from indiscriminate use of pesticides to IPM? "Once farmers adopt a technology that meets their needs economically and effectively, it's hard to get them to change," Hasse answers. "And like other farmers, Jordanian farmers have been relying on chemical pesticides for years. The pesticides are easy to apply, are financially acceptable, and ensure them against crop losses, the growers feel. But, just as the market is driven by price, so are farmers. Farmers are concerned with costs. If a new technology promises to be cheaper and as good as what they're using, farmers are prepared to overcome their fears and try it."

During 1997, he says, the price for methyl bromide almost doubled because of supply shortages when it was time to prepare the land for planting. Many farmers then turned to the cheaper solarization even though they had only heard about the technology and didn't really understand it.

At regular prices, the cost of applying methyl bromide is about $1,180 per acre ($292 per 1,000 m²), while the same area could be treated just as effectively with soil solarization for about $567 per acre ($140 per 1,000 m²).

Also, Hasse continues, research results showed other beneficial effects of soil solarization. "Plants appeared stronger and sometimes gave higher yields in these soils. There were also positive changes in the composition of soil microorganisms, especially at less-than-sterilizing temperatures. For example, beneficial organisms like the fungus Trichoderma, seem to be more heat resistant than pathogenic organisms and survive in solarized soil. But methyl bromide literally wipes out everything."

A group of rural women farmers in the Jordanian Valley has been cooperating with the IPM team. Together, they tried soil solarization in a different way. Instead of covering the soil with large sheets of clear plastic, several weeks before the season they laid down the same strips of black plastic mulch that are used for planting. In addition, they added Trichoderma under the plastic.

According to Hasse, the soil under the black plastic heats up but less than under clear plastic. The raised temperatures increase the growth of Trichoderma, while significantly reducing the growth of pathogenic fungi.

"Based on their positive experience, we did an economic assessment for small farmers. Considering that there was no need for the large sheets of clear plastic and that much less labor was required, the average cost for strip solarization (including the fungus) was reduced to about $162 per acre ($40 per 1,000 m²)," Hasse says.

Soilborne diseases increased only slightly to about 3 percent where the women used solarization in 1997. This, Hasse says, could be attributed to the very short treatment period of only 3 weeks. No soilborne diseases were observed in 1998 when they extended solarization to 5 weeks.

Growers could relate to these facts, unlike when scientists spoke of preserving the ozone layer, saving the earth for future generations, or even protecting human health.

"When introducing IPM, we proposed our technologies to several well-educated ‘pioneer farmers' for trial on small plots on their farms, providing them with technical assistance. This worked quite well because when these farmers later decided to expand the new methods to larger segments of their farms, the technology transfer process was already successfully established," Hasse explains.

But the real challenge, he says, is to bring the adapted technologies to most of the farming population of the country. Hasse and colleagues organized field days to promote contact between the pioneer farmers and the general farming population. This hands-on approach on a working farm helps experienced technical personnel to carefully demonstrate how the new methods work on farmers' own land.

"We use the pioneer farmers as experts to explain the technology to new farmers," Hasse says. "This helps avoid costly mistakes due to a lack of understanding by the new farmers."

Although the media can spread the word about using alternatives to methyl bromide, radio or TV cannot replace the benefits of the personal, hands-on experience, he notes.

Jordanian farmers accepted soil solarization because it was shown to be an economically and ecologically viable technology.

One Jordanian vegetable grower speaks highly of soil solarization. "From my experience, there is no pest in my fields that can't be controlled by solarization. I plant seeds, not seedlings in the solarized soil and get 99-percent emergence without any soilborne disease problems," says Khalil Abu Ghannam. He uses soil solarization to grow tomatoes, cucumbers, strawberries, eggplant, beans, sweet peppers, and onions. Pests and soilborne diseases controlled include Meloidogyne, Fusarium oxysporum, Pythium, Sclerotinia, Verticillium, white grub, weeds, and Orobanche.

Abu Ghannam used the following solarization processes from mid-June to mid-September, the hot off-season in the Jordan Valley:

• Remove the residues from the previous crop.
• Plow deeply.
• Add unfermented manure and rotovate the soil to incorporate the manure.
• Divide the area into plots with low dikes around them.
• Flood the soil with water, 53,500 to 64,000 gal/acre.
• Flood again after 2 weeks, 43,000 to 53,500 gal/acre.
• Plow and rotovate after 10 to 12 days to prepare soil for solarization.
• Place drip irrigation lines.
• Cover soil with clear polyethylene plastic (2-percent UV, 100 mcg) and seal the edges tightly with soil.
• Add water at 6,400 gal/acre.
• Add water every 5 days, for 45 to 50 days at 4,300 gal/acre.

Hasse notes that the water is subsidized by the Jordanian government, so farmers don't bear the full financial responsibility.

At noon on Abu Ghannam's farm, the soil temperatures are very warm: at 2 inches depth, 140°F; 6 inches, 136 to 138°F; and 8 inches, 124 to 126°F.

"My yield using soil solarization was not significantly different from what I got when I used methyl bromide to fumigate the soil," Abu Ghannam reports. "Therefore, my profit from using soil solarization is the difference of input costs."

In the Jordan Valley, solarization is primarily used on tomato, cucumber, pepper, and strawberry crops, Hasse says. "We've seen a voluntary increase in the use of solarization. This indicates that Jordanian farmers are prepared and ready to adopt this new technology. Perhaps this will help Jordan accelerate the phaseout of methyl bromide."

Last Updated: April 9, 1999