Control of Meloidogyne incognita in tomato by crambe extract using different application forms

ABSTRACT Crambe may be a viable alternative in the control of plant nematodes. The aim of the present study was to evaluate the best method for applying Crambe abyssinica extract to control Meloidogyne incognita. The first experiment was conducted in a (3x4+1) factorial design in a greenhouse, using three modes of extract application (leaf; soil; leaf + soil), in four times of application (before inoculation; during inoculation; after inoculation; and weekly until 45 days after inoculation), with an additional treatment (control). In the second experiment, factorial design was (3x2+1), with three application modes, as mentioned above, and two times of application (after inoculation and weekly). Application on the leaf after inoculation and weekly application on the soil reduced egg mass by 23.50% and 30.77%, respectively, compared to control. The reduction in the number of root-knots with weekly applications both on the soil and on the soil + leaf was 49.27%, compared to control. In the second experiment, less egg mass and total root-knots were verified with weekly applications. Second-stage juveniles (J2) and eggs per gram of root reduced after inoculation via soil + leaf and weekly inoculation via soil and via soil + leaf, showing values 55.24%, 61.57% and 60% lower than those of control, respectively. Crambe extract weekly applied on the soil showed promising for the management of M. incognita in tomato plants.