Low Permeability Tarp to Reduce Emission, Improve Efficacy and Reduce Fumigant Rates (2009-2011)
Among the emission reduction methods (field tests from 2005 to 2009), low permeability tarp VIF showed the best results in emission reduction and pest control; but field use of VIF raised concerns over potential damage in field installation from stretching because of high variability in emissions when large fields were monitored. Subsequently, a new low permeability film, TIF (totally impermeable film) became available in 2008 and this film, which has 5 or more layers, has the advantage of easier installation and is less prone to damage in the field than most VIFs. We began to focus on testing VIF for emission reduction and pest control. Two large field trials and three small plot trials were conducted from 2009 – 2011. Results from both the small and large field trials conclude that the TIF is the most effective by far to reduce emissions because it can effectively retain fumigants under the tarp. Our data leads to the conclusion that the TIF not only increased fumigant concentration under the tarp and in surface soil but also improved the distribution uniformity in soils that leads to improved efficacy. As such, reducing fumigant rates with TIF can still provide satisfactory pest control. Our research has also been focusing on effectiveness of reduced rates on pest control. Due to higher cost of TIF as compared to standard tarp, reducing fumigant rates with TIF may or may not reduce total fumigation costs, but will reduce chemical input, provide more environmental benefits, and potentially improve buffer zones or more importantly maintain fumigant availability for agricultural uses particularly for situations when no other treatments can meet the needs for the control of pests.