The Effects of Tagetes Spp. On Meloidogyne Javanica in Southern Rhodesia 1)

Abstract

Tagetes erecta, T. patula and T. minuta, when grown in M. javanica infested soil for 42 to 70 days in pots, reduce the nematode populations to low levels. T. minuta, a weed which grows vigorously in Rhodesia, has high levels of a-terthienyl in its roots but this compound, at dosages as high as 200 parts per million, when mixed in infested soil does not control M. javanica. Root-knot larvae fail to penetrate the roots of marigolds in any appreciable numbers and those that enter do not develop beyond the infective second stage larval form.