Optimizing soil disinfestation procedures for fresh market tomato and pepper production

Combinations of soil fumigation with a mixture of 1,3-dichloropropene (1,3-D) plus chloropicrin (Pic) and soil solarization for 7 days were evaluated under different plastic films and sequences of application for their effects on soilborne pests and marketable yield of fresh market tomato (Lycopersicon esculentum) and pepper (Capsicum annuum). Shank injection of fumigants under a virtually impermeable film (VIF) using a novel application apparatus dramatically improved their retention in the soil. Survival of Fusarium oxysporum f. sp. lycopersici in soil declined significantly when fumigation or solarization was combined with VIF compared with either soil disinfestation treatment applied under low-density polyethylene. When compared with an untreated control, significant reductions in yellow nutsedge (Cyperus esculentus), purple nutsedge (C. rotundus), and root-knot nematodes (Meloidogyne spp.) were achieved with a reduced dosage of fumigant when applications were made 7 days after planting beds were covered with VIF. A 7-day delay in fumigant application in beds covered by low-density polyethylene significantly increased marketable yield of pepper when compared with an untreated control. The results demonstrate that chemical and nonchemical soil disinfestation methods can be combined with novel application technology and procedures to improve their spectrum of pest control and reduce fumigant application rates.