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United States Department of Agriculture

Agricultural Research Service

Research Project: Retaining Export and Food Security of U.S. Specialty Crops: Low-Emission Methyl Bromide Fumigations for Quarantine and Pre-Shipment Uses

Location: Commodity Protection and Quality

2013 Annual Report


1a.Objectives (from AD-416):
This proposal addresses concerns of U.S. exporters with respect to European Union (EU) chemical regulation policies, which could disrupt trade of specialty crops, including dried plums.


1b.Approach (from AD-416):
Important features of the proposed research include: the comparative evaluation of contemporary containment and reuse methods with methyl bromide (MB) versus registered alternative fumigants (i.e. phosphine, ozone, sulfuryl fluoride, propylene oxide), the development of novel technologies to reduce and eliminate atmospheric emissions of fumigants, the utilization of an experimental scale-up approach that begins in laboratory chambers and culminates in commercial chambers with commodity-specific industry input, and an economic cost analysis of promising technologies, particularly those applicable to quarantine & pre-shipment postharvest scenarios.


3.Progress Report:

This Trust agreement was established to support Objective 1 of the in-house project and is related to reducing atmospheric emission of methyl bromide from postharvest applications. Methyl bromide (MB) is a highly effective post-harvest fumigant, that has a long history of controlling insects and microorganisms across a wide variety of applications. MB released into the atmosphere is a major source of atmospheric bromine radical, which is a known ozone depletor, and all but the most critical of uses are banned by international agreement under the Montreal Protocol. In the instances that MB use is permitted, it would be beneficial to prevent the release of MB following the fumigation by trapping the effluent onto activated carbon or some other type of adsorbent material. To that end, it is necessary to rapidly screen potential sorbents for their effectiveness in capturing methyl bromide from aeration streams. An experimental apparatus was designed to screen gram-scale quantities of potential sorbents in parallel as a function of commercially-applicable aeration flows, durations, and MB concentrations. Solid phase micro-extraction (SPME) fibers were integrated into the apparatus for sampling MB over a range of concentrations, flows, and sample volumes, in conjunction with gas chromatographic analyses. Research enabled the direct comparison of capture performance, with carbon generated from plum pits sorbing more MB than carbons generated from walnuts, almonds, or peach pits. The goal of this research is to deliver a economically viable technology to the US agriculture so that critical MB uses can continue and regulatory objectives of the Montreal protocol are met.


Last Modified: 9/22/2014
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