African marigold (Tagetes erecta) and Crotalaria juncea were used as intercrops to control root knot nematodes on a susceptible tomato cultivar, Ibadan local in a pot experiment at the roof top of Crop Protection and Environmental Biology Dept, University of Ibadan, Ibadan, Oyo State, Nigeria. Four weeks old tomato plants intercropped with African marigold (Tagetes erecta) and Crotalaria juncea were inoculated with 5000eggs of root knot nematodes. Results indicated that absence of marigold or Crotalaria plants in the inoculated treatments led to increase in the number of second stage juvenile of root knot nematodes. The antagonistic plants produced significant reduction (P<0.05) in the root gall indices, reproductive factor and final nematode population in susceptible tomato plants roots. However, no significant differences were observed across the treatments in terms of mean number of leaves and plant heights. The results obtained have important implications for the design of alternative nematode management strategies using antagonistic plants. Keywords: antagonistic plants, root-knot nematodes, Gall index, Reproductive factor
