Barrier Films and Strawberry Production
A gas impermeable film can minimize fumigant emissions, increase fumigant retention over time, and reduce the amount of fumigant needed for effective pest control (Gamliel et al., 1998; Minuto et al., 1999; Wang et al., 1999). Use of virtually impermeable film (VIF) can greatly reduce fumigant emissions and enhance their retention in the upper soil layer relative to conventional polyethylene films or uncovered soil (Nelson et al., 2001; Chellemi and Mirusso, 2002). VIF differs from traditional high density polyethylene tarp because VIF has additional gas impermeable layers (such as nylon or polyaminides) between polyethylene layers (Wang et. al. 1997).
A relatively new barrier film known as “Totally Impermeable Film” or TIF has been shown to retain fumigant better than VIF (Chow 2008). TIF is a five-layer film with two thin ethylene vinyl alcohol layers embedded in three layers of standard polyethylene film (Chow 2008). In Ventura County the Agricultural Commissioner fumigant use regulations allow the application of twice as many pounds of chloropicrin per 48-hour period where TIF is used than under a conventional 1.25 mil film (Ventura County Agricultural Commissioner 2011). In a previous paper published in California Agriculture, Fennimore and Ajwa (2011) found that TIF was effective at trapping fumigants, improving weed control and boosting yields. By trapping the fumigant under TIF, higher fumigant concentrations kill a greater percentage of the weed seed and soil pathogens thus improving soil pest control and yields.
MB Alternatives Fumigant Concentrations
Higher fumigant concentrations of 1, 3-D and Pic were measured under VIF compared with low density polyethylene (LDPE) tarp, 1 to 4 d after drip fumigation (Desaeger and Csinos, 2005). Improved retention of fumigants in soil under VIF also provides more opportunity for soil degradation of fumigants instead of their release into the atmosphere (Wang and Yates, 1998). Many researchers have found that VIF as a tarp can reduce 1, 3-D plus Pic needed for effective soil disinfestations by 50% (De Cal, 2004; Medina et al., 2006; Porter et al., 2006). Santos et al. (2005, 2007) found that reducing MBPic rates by one-half under VIF controlled nutsedge similarly to full-rate MBPic 350 pounds per acre applied under standard (STD) films.
Learn more about Field Evaluation of VIF in California