Root-Knot Nematodes Meloidogyne Spp. Root-knot nematodes affect forage legumes by causing premature stand loss and reduced forage yields. Root-knot nematodes attack many legumes grown in Alabama such as alfalfa, lespedezas, vetches, and crimson, white, and arrowleaf clovers. Five species of root-knot nematodes commonly attack forage legumes in Alabama. Plants infected with root-knot nematodes are stunted and stands are reduced.
Plants often wilt, turn yellow, and die.
The main diagnostic symptom is the presence of swellings or galls on the roots. Galls on roots can be round or long and irregular in shape. Disease Cycle . The infective stage of Meloidogyne spp. is the newly hatched larvae. They infect the tender plant tissue near the root tip where their feeding stimulates the formation of a gall or knot around the infection site.