Abstract
Fumigation efficacy depends on the duration that the fumigant stays in the soil, which is influenced by the mulch permeability. Methyl bromide (MBr) retention of high and low density polyethylene mulches, and metallized and virtually impermeable films (VIF) were tested with a rate of 175 lbs MBr/acre and compared with a full-rate control (350 lbs/acre) using low-density polyethylene mulch and a non-fumigated control. Four days after treatment, MBr concentration in the soil was 700 and 600 ppm higher with VIF and metallized mulches, respectively, as compared to low-density polyethylene mulches. Four weeks after MBr application, VIF and metallized films had the lowest nutsedge densities among all treatments. These results showed that reduced MBr rates can be used in combination with VIF and metallized films, without affecting nutsedge control efficacy.
