Septoria nodorum (Berk.) Berk. - Leaf and glume blotch of barley

Systematic position.

Class Deuteromycetes, order Sphaeropsidales (Pycnidiales), family Sphaeropsidaceae, genus Septoria. Teleomorph: Phaeosphaeria nodorum (E. Mull.) Hedjar: class Ascomycetes, subclass Loculoascomycetidae, order Pleosporales, family Pleosporaceae.

Biological group.

Facultative parasite of barley (Hordeum vulgare) and other species of genera Hordeum, Triticum, Secale, Elytrigia, Aegilops, Alopecurus, Bromus, Festuca, Poa, Stipa.

Morphology and biology.

Straw, seed, and winter barley plants are sources of primary inoculum. The first symptoms appear in the spring as brown spots on leaf blades and leaf sheaths or at the junction of blade and sheath. Later oval red brown spots of 1-2 cm in length develop along leaf veins, having chlorotic margins. The dark brown pycnidia are scattered throughout the lesions. Infected stem nodes turn brown, shrivel, and are speckled with dark pycnidia. Pycnidia may develop also on seed surface. They are brown, globose, 66-150mkm in diameter, half-sunken beneath the epidermis of infected host tissue. Conidia are hyaline, 13-38.4 x 2.0-3.0.m, with one to three sepae, and rounded at their ends. In culture, the fungus produces dark violet colonies with pink to white mycelium at the margins. The distinction between wheat and barley biotypes is based on differences in their colony morphology and hosts. Conidia produced during wet periods are disseminated by splashing rain and initiate infection throughout the growing season. Pycnidia in lesions are followed by pseudothecia in late summer. Pseudothecia are immersed by host tissue; they are dark brown to black, globose (160-300 mkm in diameter), and having a short papillate ostiole. Asci are club-shaped and bitunicate, bearing eight ascospores. Ascospores are prevalent during late summer, being predominantly windborne. Germ tubes of both types of spores penetrate barley directly and through stomata. Isolates of barley biotype of S. nodorum are pathogenic only for barley.


Disease is widely distributed throughout the world. In the former USSR it occurs everywhere in areas of barley cultivation.


Infection requires 6 hr of wetness. Spore germination and infection are optimal at temperatures between 15 and 25.C, but they can occur between 5 and 35.C. Incubation period depends on weather conditions, lasting 10 to 20 days. Wet and windy weather favor epidemics.

Economic significance.

S. nodorum is most important in the Volga Basin, Northern Caucasus, Central Chernozem Regions, north-western and central parts of the Non-Chernozem Region, in the Ural and Siberia. The data on epiphytoty frequency and yield losses are absent.

Related References.

Borzionova T.I., Basetskaya M.N., Sudnikova B.P., Alipbekova C.A. 1991. Species composition of causal agents of Septoria leaf blotch on the territory of Kazakhstan, Western Siberia, South Ural, and Kyrgyzstan// Sibirskii Vestnik Selskokhozyaistvennoi Nauki. N3. P. 106-108 (in Russian).
Goncharenko M.P. 1998. Cereal diseases. For what the agriculturist need to prepare// Zashchita Rastenii. N2. P. 2-3 (in Russian).
Gorobei I.M., Ashmarina L.F. 1996. Species composition and dynamics of barley diseases in forest-steppe of Western Siberia// Sibirskii Vestnik Selskokhozyaistvennoi Nauki. N 3-4. P. 61-64 (in Russian).
Ishkova T.I., Berestetskaya L.I., Gasich E.L., Levitin M.M., Vlasov D.U. 2000. Diagnostics of the main diseases of cereals. Saint Petersburg. 76 P. (in Russian).
Kovalenko S.N. 1986. Study of Septoria leaf blotch on barley in Ukraine // Zashchita selskokhozyaistvennykh kul.tur ot vreditelei I boleznei. P. 25-29 (in Russian).
Mathre D.E. (Edit.). 1997. Compendium of barley diseases. APS PRESS. 90 p.
Nguen Van Than. 1976. The review of species Septoria Sacc. on cereals in Leningrad Region// Vestnik Leningradskogo Gosudarstvennogo Universiteta . N 21 (in Russian).
Novozhilov K.V., Zakharenko V.A. (Eds.). 2000. Levels and tendencies of variability of species composition and intrapopulation structure, areas of complexes of harmful and useful organisms and forecast of dangerous phytosanitary situations in zones of the country. St.-Petersburg. 100 P. (in Russian).
Peresypkin V.F. 1969. Agricultural Phytopathology. Moscow: Kolos, 479 P. (in Russian).
Polozova N.L.1971. Septoria leaf blotch on cereal crops in Leningrad Region// Zapiski Leningradskogo sel.skokhozyaistvennogo instituta Institute. V. 156. P. 91-94. (in Russian).
Sanin S. S. 1995. Phytosanitary monitoring: modern state and ways of improvement. In book: Problems of Optimization of Phytosanitary State in Plant Industry. Sbornik trudov Vserossiiskogo s.ezda po zashchite rastenii. St.- Petersburg. P. 166-175. (in Russian).

© Afanasenko O.S.


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