黄麻の新病害炭疽病

抄録

(1) The present paper deals with the study carried out by the writers on a new fungus which causes an anthracnose disease of jute.
(2) The jute anthracnose affects the stems, leaves and pods of this crop and its presence in Kumamoto and Shizuoka Prefecture was first observed in 1938. In the next year it has been found in Aichi Prefecture.
(3) The causal organism has been isolated and its pathogenicity has been proved by inoculation experiments. The incubation period is about three days.
(4) As the fungus seems to be new to science, the name Colletotrichum Corchorum is proposed and a brief technical description is given, as follows:
Colletotrichum Corchorum IKATA et TANAKA nov. sp.
Lesions on stems, leaves and pods, brown to black, not sunken, definite in outline. Acervuli black, superficial, scattered; stroma patelliform, 100-350μ in diameter by 25-50μ high; setae several to abundant, originating from margin of stroma, yellowish brown to black and becoming lighter toward the apex, 2 to 5 septate, 36-117 μ long by 3.6-5.0 μ wide. Conidiophores simple, hyaline, arising from stroma, 15-35 μ long by 3-4 μ wide; conidia abundant, non-septate, hyaline, curved, bluntly tapered, oblong-fusoid to falcate-fusoid, 12-25×3.6-6.0μ, with 16-22×4μ as the most common size.
HAB: Parasitic on stems, pods and leaves of Corchorus capsularis L.
(5) The optimum temperature for growth of the fungus is 30°C.
(6) The disease is seed-borne, the fungus mycelium exists in the seed and spores are adhering on the external part of seeds.