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Spot-causing fungal disease occurring from the end of summer to autumn in Hokkaido. It produces brown, oval lesions of 2-4 x1 mm in size mainly in the leaf. The lesions become characteristic ones like bird's eyes forming yellow halos in the surroundings. The pathogenicity of the causal organism is different from that of redtop. |
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Fungal disease which inhibits heading and becomes problem in seed production. The white stroma of 1-3 cm in length like a head of bulrush are produced rolling the sheath of flag leaf in late spring. A lot of conidia are formed on the stroma and the heading of the infected plant is inhibited. When the disease advances, the stroma turn to yellow, perithecia are produced inside and ascospores are released. The causal organism is a so-called endphyte which lives symbiotically in the plant body and known to produce anti-insect alkaloids. The infected plants are known to acquire the resistance to purple spot. |
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The ergots (sclerotia) are formed in the head and have toxicity to livestocks. The disease at first produces light-brown honey dew in the head just after flowering, and many spores included in the honey dew disperse and transmit by wind and rain. The black purple, cattle-horn like, ergots covered with white sphacelia of 2-18mm in length and 0.6-2.4mm in width are produced in the infected flowers replacing the seeds. The ergots drop to the ground, germinate in next year, and disperse ascospores as primary inocula. The host range is wide and the pathogen can also infect wheat, rye, orchardgrass and fescue, etc. The alkaloids in the ergot are strongly toxic such as ergovaline and cause abortion and so on of livestocks. |
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Fungal disease which causes leaf blight occurring from early spring. The lesions are drab, rectangular to long oval and about 2-5 x 1-2 mm in size. They are often produced from leaf tip and the surrounding of the lesion often turns to yellow. They fuse mutually when occurring severely and causes leaf blight. The causal organism is one of the Helminthosporium fungi and parasitize only in timothy. |
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Fungal disease which causes leaf rot occurring in cool places in early summer. Infected leaves remain unfold and become white from the leaf tip, rolling and killed. Lesions are ellipsoidal to uncertain shape, grayish white with light brown border, producing grayish black, spherical to sub-shperical and smooth sclerotia of 1-3 mm in diameter. Infected plants increased in number and resulting patch in grasslands. The causal pathogen does not infect reed canarygrass that is known as a host plant in Japan. The same disease occurs also in quackgrass (Agropyron repens) in Hokkaido, the most northern region of Japan. |
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Spot-causing fungal disease occurring all over the country. The disease prohibits the seed production. The lesion of brown to purple brown, short line shaped, 2-3mm in length and 0.5-1 mm in width appears between the leaf veins at first. They gradually expand to 2-3 cm in length and fuse one another. At last, the whole leaf becomes ash white and killed. The spores which look like small black molds are produced on the old lesion, and they disperse and spread. The pathogen can infect orchardgrass, tall oatgrass and etc., but the pathogenicity is considered to be differentiated. |
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Fungal disease which causes leaf blight mainly occurring in Hokkaido. The disease produces at first reddish brown spots in the leaf, then the lesions expand to ash white, long oval lesions with reddish brown border. The size is about 1-3 cm in length and 1-3 mm in width, and the boundary of the lesion is distinct. The lesions fuse mutually and cause leaf blight when occurring severely. |
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The most general spot-causing fungal disease of timothy occurring in the northern regions and cool high land. It occurs from spring to autumn and spreads in summer. The lesions are at first purplish black small spots and then become round and ash white ones of 2-3 mm in diameter with purplish black back border. When occurring severely, it causes leaf blight with rolling from leaf tip. The causal organism parasitize only in timothy. |
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Important fungal disease which causes plant death in Hokkaido and Tohoku Dist. The disease distributes in the region where the frozen period of soil is long. The entire plant becomes water-soaked and discolors to deep green and softened immediately after snow-melting like boiled. It becomes ash brown when drying and black, large sclerotia of 5-10mm in size like the excrement of rat are formed on the surface. Stroma come out from the sclerotia at late autumn and ascospores disperse as inoculum sources. The causal organism is polyxeny and barley, wheat, fescue, ryegrass, timothy, redtop, and etc. are reported to be infected. Orchardgrass and ryegrass are the weakest grasses to the disease. |
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Typical rust disease of timothy. It produces swelling lesions peculiar to the rust disease at the early spring. The lesion are reddish brown to iron rust color, oval to sripe ones of 1-2 mm in length and 0.5-0.6 mm in width. They fuse mutually and become irregular shape. The epidermis tears when maturing and it disperses reddish brown urediniospores from the inside. The lesion becomes blackish brown and forms teleutospores for overwintering in summer to autumn. The alternate host of the pathogen is considered to be kinds of Berberis. The species of the pathogen is same with other stem rust fungi, but the pathogenicity is differentiated. |
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Spot-causing fungal disease occurring in the cool region. The disease occurs in leaves and sheaths. The lesions are rectangular shape, ash white, 1-2 mm long with brown thin border. The lesion is delimited by leaf veins and becomes distinct with a clear boundary. The pycnidiospores in the pycnidia formed on the lesion disperse by wind and rain and the disease spreads. |
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