Fumigant emission reductions with TIF warrant regulatory changes

• Published in: California agriculture (Berkeley, Calif.) Calif.), 2013-07, Vol.67 (3), p.147-152
• Main Authors: Ajwa, Husein, Stanghellini, Michael S, Gao, Suduan, Sullivan, David A, Khan, Afiqur, Ntow, William, Qin, Ruijun
• Format: Article
• Language: English
• Subjects: Control; Fumigants; Pests; Properties
• ISSN: 0008-0845; 2160-8091
• DOI: 10.3733/ca.v067n03p147

With methyl bromide s phase-out, most growers have turned to alternative fumigants, particularly 1,3-dichloropropene (1,3-D) and chloropicrin. These alternatives are tightly regulated because they are classified as toxic air contaminants and volatile organic compounds; the latter combine with other substances to produce ground-level ozone (smog). Two ambient air monitoring studies were conducted to evaluate the potential of totally impermeable film (TIF) to reduce emissions from shank applications of chloropicrin and 1,3-D. In 2009, a study demonstrated that TIF reduced chloropicrin and 1,3-D peak emissions by 45% and 38%, respectively, but TIF did not reduce total emissions when it was cut after 6 days. In 2011, increasing the tarp period from 5 to 10 days decreased chloropicrin and 1,3-D peak emissions by 88% and 78%, and their total emissions by 64% and 43%, respectively. Concurrent dynamic flux chamber results corroborated the ambient air monitoring data. These studies provide regulatory agencies with mitigation measures that should allow continued fumigant use at efficacious application rates.