Pre-plant soil fumigation with reduced rates under low permeability films for nursery production, orchard and vineyard replanting

Abstract

Pre-plant soil fumigation in California is a common agricultural practice in orchard and vineyard replanting as well as in nursery production of fruit and nut trees. Identification of pest control strategies with low chemical inputs to reduce environmental impact are of interest. Therefore, the objective of this investigation was to evaluate the efficacy of reduced Telone C35 (61% 1,3-dichloropropene and 35% chloropicrin) rates under high density polyethylene (HDPE) or a totally impermeable film (TIF) against plant-parasitic nematodes, soilborne pathogens and weeds. Fumigation at full (605 kg/ha), half, or one quarter of the full rate, was highly effective for controlling plant parasitic nematodes and weeds under both HDPE and TIF. The reduced rates performed well against the soilborne pathogens Pythium ultimum and Verticillium dahliae but did not control Fusarium spp., and Phytophthora cactorum. Soil gas evaluations demonstrated that TIF retained more fumigant in soil compared to HDPE and bare soil when applied at equivalent rates. This investigation demonstrated the potential of reduced rates for the control of a variety of common pests, pathogens and weeds in replanting situations.