The impact of different treatments on population of three nematode species associated with guar (Cyamopsis tetragonoloba) and the yield of guar were investigated. The chemical nematicides and plant extracts significantly reduced the population densities of all three nematodes. Carbofuran was most effective against all the nematodes. Apart from other three treatments, Tridax procumbens emerged as an effective phytonematicide. Helicotylenchus indicus, Rotylenchulus reniformis and Meloidogyne incognita had similar population density levels and were more or less equally suppressed by all the treatments in the order: Carbofuran > Tridax procumbens > Fertinemakil Plus > Withania somnifera. The yield of guar was only slightly increased but not significantly.