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One of the rust diseases and the damage is not so large. It produces orange yellow, oval, swelling lesions of about 1mm in length in the leaf, sheath, and culm. The lesions are characteristic to appear in a row along the leaf vein. The epidermis tears when maturing and disperses urediniospores. Ash yellow telia often occur on the leaf back, upheave not so much. The causal organism is considered to be same with that of yellow rust of bluegrass. |
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Fungal disease occurring in Hokkaido, the northern part of Japan. The damage becomes distinct from June to July. The black powdery stripes are formed on the leaf, sheath and culm. The surface of the lesion tears and exposes black powder, the smut spores, and they disperse by wind and rain. The lesion part often splits later. The infected plant often shrinks and can not do heading. |
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An Important fungal disease which occurs all over the country and becomes a cause of summer depression of grassland. Ash green and water-soaked lesions appears at first and the whole infected plant soften like being boiled before long. Then, the infected stalks and leaves fall one upon another and rot when the disease progresses and hyphae like spider' web appear covering all the infected part. Later light brown to brown sclerotia of about 5mm in diameter are produced on the infected part. At this point, the infected grass withers forming patches and the grassland gradually becomes bare land. The causal organism is polyxeny and can infect most grasses and legumes of herbage. AG-1 IB and IA of R.solani cause the disease.
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Important fungal disease which causes plant death and occurs mainly in Hokkaido, the most northern part of Japan. The symptom is similar that of T.ishikariensis, but the sclerotia formed on the surface of withering part is reddish brown and millet grain size. The sclerotia is formed on the stalks, leaves, and roots, etc. of the withering plant. The pathogen is more saprophytic than T.ishikariensis and is considered to invade after invasion of T.ishikariensis and occur mixingly with it. |
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Important fungal disease which causes plant death and occurs mainly in Hokkaido Dist. The symptom appears just after snow-melting. Stems and leaves become water-soaked and softened like boiled. When they are dry, they discolor to ash brown. Dark brown to black, globular to irregular sclerotia of 0.5-1mm in diameter are produced on them. The pathogen is classified to three different biotypes. Biotype A and B distributes in the much and little snowing regions, respectively. Biotype C distributes in both regions. These groups are different not only in their distribution but also their pathogenicity and fertility, etc. |
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Fungal disease that produces large lesions on leaves and occurs mainly in Kanto District. The disease at first produces spindle-shape spots of copper color in the leaf, but the lesion soon becomes a large one with irregular zonation crossing the leaf. The lesions fuses later and this causes leaf blight. Small black grains can be seen sometimes in old lesions. The pathogen is a same species with that of sorghum, etc. But some differentiations of pathogenicity are considered to be occurring. |
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