Septoria Leaf Blotch

Septoria Leaf Blotch

 

any one of a group of plant diseases caused by fungi of the genus Septoria and characterized by the formation, mainly on the leaves, of small, mostly rounded spots, which are dark at the periphery and light, sometimes almost white, in the center. Infected grain crops are distinguished by elongate blotches.

The most common and harmful are Septoria leaf blotch of grain crops (causative agents Septoria graminum, S. nodorum, and other species), tomato (S. lycopersici), and currants and gooseberries (S. ribis). Septoria leaf blotch also attacks millet (S. panici-miliacei), hemp (S. cannabis), soybeans (S. glycines), grapes (S. ampelina), and many other plants. The majority of the causative agents are preserved on plant remains. Distribution of spores and infection of plants occur in damp weather, when the pycnidia swell. With severe infection, the leaves and shoots become dry, and the stems turn brown, wrinkle, and often bend over. Premature leaf fall, necrosis of husks, and underdevelopment of grain (in cereals) are also observed.

Control measures include destroying plant remains, using crop rotation when cultivating annual crops, spraying plants with fungicides, growing resistant or less susceptible varieties, and applying a complete mineral fertilizer.

REFERENCE

Peresypkin, V. F. Sel’skokhoziaistvennaia fitopatologiia. Moscow, 1969.

M. I. DEMENT’EVA

References in periodicals archive ?
Schuh, "Influence of tillage systems on disease intensity and spatial pattern of Septoria leaf blotch," Phytopathology, vol.
Azoxystrobin helps in protecting crops against prevalent fungal diseases including Septoria leaf blotch, rye leafrust (Puccinia triticina), stripe rust, powdery mildew, wheat leaf rust (Puccinia recondita), and downy mildew.
Typical symptoms of septoria leaf blotch appeared as chlorotic spots with the presence of small black dots that are pycnidia.
Mainly the accessions in the germplasm belonging to the groups which were classified as resistant against rusts septoria leaf blotch and hessain fly were showed high degree of resistant against aphids.
Effect of sowing densities on Septoria leaf blotch development and its subsequent effects on yield compoments of wheat.
In addition to resistance to leaf rust, AR93005 is resistant to prevalent local races of stripe rust (caused by Puccinia striiformis Westend.) (0% infection compared to 41% for Coker 9663) and moderately resistant to Wheat soilborne mosaic virus (rating of 1.5 compared to 5.2 for Coker 9663 on a 0-9 scale) and Septoria leaf blotch (caused by Septoria tritici Roberge in Desmaz.).
Infestation with Septoria leaf blotch and glume blotch was less severe on Grant than on Caldwell.
The Effect of Agronomic Practices on the Development of Septoria Leaf Blotch and its Subsequent Affect on the Yield and Yield Components of Wheat: American-Eurasian Journal of Sustainable Agriculture., 3(1): 57-67.
AR 910 is moderately susceptible to Septoria leaf blotch and susceptible to Wheat spindle streak mosaic virus and tan spot [caused by Pyrenophora triticirepentis (Died.) Drechs.].
triticina Eriks.), and reaction to Septoria leaf blotch (caused by Septoria tritici Roberge in Desmaz.).
In field tests (1999-2002), adult plants of Thoroughbred have expressed resistance (0 = resistant to 9 = susceptible) to powdery mildew (1.3) and Septoria leaf blotch (0.2) (caused by Septoria passerinii Sacc.).
On the basis of disease assessment scores reported in the 2001 and 2002 UESRWWN on a scale ranging from 0 to 9 (where 0 = no visible disease symptoms and 9 = severe infection), Truman is moderately resistant (score = 24) to Septoria leaf blotch [caused by the fungus Mycosphaerella graminicola (Fuckel) Schroeter (anamorph: Septoria tritici Roberge in Desmaz)]; however, disease infection may be underestimated because of Truman's later maturity.