Management of root-knot nematodes in carrots using Neem (Azadiractha Indica) leaf extract

Abstract

The study was conducted to assess the effect the neem tree leaves (Azadirachta indica) extract on the management of root-knot nematodes in carrots. The study specifically determined the effect of A. indica leaf extract concentration in management of root-knot nematodes in carrots; and determined the effect of A. indica leaf extract concentration that suppresses galling and forking incidence on carrot tubers. The experiments were conducted at the Kyambogo University farm in two rainfall seasons of 2019B and 2020A. Treatments composed of three levels of concentration of A. indica leaf extract (i.e 15, 25 and 35g) plus a positive control (distilled water) and a negative control (no inoculum). Data was collected included number of standing leaves on the plant, height of the shoot, fresh and dry weight of leaves, fresh weight of carrot tubers and gall incidence. Results showed that there was no significant difference between the negative control (no inoculum applied), distilled water (inoculum applied) and highest concentration level of neem leaf extract (35g) on the number of standing leaves in carrots. Neem leaf extract was found to have significant effect on galling and forking incidence of carrot tubers (P<0.001) The study provides evidence of the effectiveness of neem tree leaves extracts in the management of root- knot nematodes in carrots.