The host efficiency and sensitivity of three Trifolium repens cultivars (Regal, Louisiana S-1, Osceola) and two germplasms (SC-1, Brown Loam Synthetic No. 6) to eight populations of Meloidogyne incognita representing races 1, 2, 3, and 4 were determined in greenhouse experiments. Roots were stained with Phloxine B and rated for nematode egg masses and galling. The three cultivars and two germplasms were excellent hosts for all eight M. incognita populations. Populations from all four M. incognita host races severely galled the roots of the white clover cultivars and germplasms. A tolerance index was calculated for each white clover-nematode treatment. SC-1, which was released as a root-knot tolerant germplasm, exhibited moderate tolerance to a race 1 and a race 4 population, and Louisiana S-1 was moderately tolerant to a race 2 population.