Evaluation of the protective and therapeutic properties of DBCP for control of root-knot nematode on tomato.

Twelve soil drenches over a period of 30 days with DBCP concentrations of 40 microg/ml did not completely prevent infection of tomato plants by root-knot nematode juveniles. Repeated DBCP drenches of 40 microg/ml halted gall development during the drenches, but 10 days after drenching was discontinued galls were apparent. DBCP drenches at 200 microg/ml prevented tomato root development, and 40 microg/ml slowed it. Ten microg/ml increased the height of root-knot-infected plants, but not their top weights. Treated plants were lanky. Protective drenches of 2.5 to 40 microg/ml of DBCP decreased nematode populations and increased fruitfulness. DBCP as a therapeutant reduced the incidence of galling on new roots and halted increases in gall size on previously infected roots but did not improve fruitfulness or plant size significantly.