Pathogenicity of Trichodorus porosus to Chinese Yam

Abstract

A kind of disease of unknown etiology, which belongs to “black scurf-like” syndrome, has long been recognized in a Chinese yam-producing area at Matsushiro, Nagano. In order to clarify the cause of the disease, the potted young seedlings grown from the bulbils were inoculated with each of three nematode species having been recovered from the diseased yam fields. Of these three nematodes, the characteristic symptoms of the tubers identical with those naturally occurring were reproduced only by the inoculation of Trichodorus porosus Allen in the duplicated experiments conducted under different temperature and soil conditions.