Black polyethylene film mulches affect the activity of some nematicides (1, 2, 3, 5, 6, 7, 8, 9). Other mulches also may influence the results of fumigat ion tests; for example, hay mulches, cause the soil to remain cooler (8). Salt-hay mulches are used by strawberry growers, many of whom fumigate. Mulches of grass clippings, wood chips, or leaf mold are used by homeowners. Clear plastic mulche...