PENETRATION OF CROTALARIA-JUNCEA, DOLICHOS-LABLAB, AND SESAMUM-INDICUM ROOTS BY MELOIDOGYNE-JAVANICA

Penetration of Crotalaria juncea (PI 207657 and cv. Tropic Sun) Dolich os lablab cv. High-worth, and Sesamum indicum by juveniles U2) of Melo idogyne javanica was assessed to investigate the mechanism by which th ese plants may reduce nematode numbers in the field. Growth chamber ex periments were conducted at 25 C, with vials containing 90 g sand infe sted with 450 J2; tomato (UC 204 C) was included as a susceptible host . Fifteen days after inoculation, roots were stained and the nematodes within stained roots were counted. Both C. juncea lines were highly r esistant to penetration, as they contained significantly fewer nematod es per cm of root and per root system than the other plants. Although containing more nematodes per cm of root than C. juncea, S. indicum an d D. lablab had significantly fewer nematodes per root system and per cm of root than tomato. Roots were significantly longer in the plants with the lowest nematode penetration. Although C. juncea, D. lablab, a nd S. indicum may have potential utility as cover or rotation crops in soil infested with M. javanica, further quantitative information on t he reproduction of M. javanica and other nematodes in these plants is needed.