Criconemoides ornatus Parasitic on Peanuts

Roots, pods, and pegs of 'Argentine' and 'Starr' peanut cultivars inoculated with Criconemoides ornatus were severely discolored with brown necrotic lesions. Nematodes were attached to roots, pods, and pegs often in large numbers. Small necrotic lesions were often superficial, but necrosis in large lesions usually extended deep into the tissues. Lesions were present on roots of all ages. Many lateral root primordia, and young roots were killed resulting in reduced numbers of laterals. Pod yields from nematode infected plants were reduced about one-half.