Septoria glycines Hemmi. - Septoria Brown Spot of Soya.

Taxonomic position.

Class Deuteromycota, order Sphaeropsidales, family Sphaeropsidaceae, genus Septoria. Ascigerous stage Mycosphaerella uspenskajae Mashk. et Tomil.

Biological group.


Morphology and biology.

Sources of the infection are infected seeds and vegetation residues. Rounded surface red-brown spots appear on cotyledons, 6-10 mm in diameter, having numerous pycnidia. True leaves have spots of two types, small (reddish-brown, angular) and large, 1-5 mm in diameter, limited by veins. The tissue surrounding lesions becomes chlorotic. Those leaves fall. The Septoria development begins from the lower leaves. The spots are much smaller on beans, than on leaves. The spots are lengthened, reddish-brown on stems. Pycnidia are sunken, with projecting stoma, rounded, dark-brown, 46.3-111.0 microns in diameter. Conidia are colorless, threadlike, bent, with 1-4 septae, 22.75-55.5 x 1.7-2.5 microns in size. The fungus spreads during the vegetation period by pycnospores, repeatedly infecting leaves of soya. The incubation period lasts 7-10 days. Mycelium and pycnidia over-winter.


The disease occurs in Western Europe, India, Japan, Korea, Brazil, Moldova, Ukraine. In Russia the pathogen occurs in the Far East, the Northern Caucasus, in Central Chernozem zone.


Air temperature 26-28.C and relative humidity 90% and higher are optimum for this species. Frequent rains, plentiful dews, and high temperature in the second half of July and in August promote severe development of the Septoria Brown Spot.

Economic significance.

The pathogen is highly specialized, affecting cultural and wild-growing soya. Septoria Brown Spot harmfulness causes reduction of assimilating activity of plants and total premature abscission of leaves. Green yield of fodder varieties is considerably reduced. Control measures for soya include crop rotation, autumn plowing to a depth of 22 cm along with burying of vegetation residues, careful separation of seeds, timely sowing, seed dressing, fungicide spraying of plants upon first symptoms of the disease, use of resistant cultivars.

Reference citations.

Prostakova Zh.G., Ganya A.I. 1983. Fungal diseases of soybean and their control. Kishinev: Shtiintsa, 35 p. (in Russian).
Zaostrovnykh V.I. 2005. Diseases of soya. Zashchita i karantin rastenii (Moscow) 2: 49-53 (in Russian).
Zaostrovnykh V.I., Dubovitskaya L.K. 2003. Harmful organisms of soya and system of phytosanitary optimization of its crops. Novosibirsk: Kemerovo SKHI, Dal.nevostochnyi GAU, 528 p. (in Russian).

© Kungurtseva O.V.

Photo Kungurtseva O.V.

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