The plant-parasitic nematodes most frequently found associated with cassava, Manihot esculenta Crantz (syn. M. ullissima Pohl.), throughout the world are: Pratylenchus brachyurus (Godfrey) Filipjev & Schuurmans Stekhoven, Rotylenchulus reniformis Linford & Oliveira, Helicotylenchus spp., Scutellonema spp., and Meloidogyne spp. Only P brachyurus and Meloidogyne spp. are considered economically damaging to the crop, with root-knot nematodes the most widespread. Damage from Meloidogyne spp. usually depends on the population level, however the many differences in responses of various cassava cultivars to Meloidogyne species suggest that use of resistant or tolerant cultivars may be the most practical method for managing root-knot nematodes on this crop. Data are presented relating yield of the cassava cultivar 'Senorita' in southern Florida directly to weight of the seed piece and inversely to high populations of Meloidogyne incognita (Kofoid & White) Chitwood. Marketable yield of the cu
