IMPROVED TECHNOLOGIES TO REDUCE EMISSION OF METHYL-BROMIDE FROM FUMIGATED SOIL

Methyl bromide (MB) is the chemical most widely used for soil fumigati on in intensive agriculture, and for commodity and postharvest quarant ine treatments. MB was listed by the Montreal Protocol in 1992 as a co ntrolled ozone-depleting substance, and a phaseout process has been in itiated. Several technologies to reduce the fumigation dosage and subs equent emission of MB from the fumigated soil were tested and applied in field trials and commercial application. These include dosage reduc tion by using impermeable films, improving uniformity of distribution, and preventing possible escape sources such as the edges of the fumig ated plot. Combining MB with other pesticides, solarization, or biocon trol agents is another approach to reducing MB emission and dosage. Ad apting these technologies may result in a 60-90% reduction of MB emitt ed from fumigated soil.