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 ?
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.
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.
and reaction to Septoria leaf blotch [caused by the fungus Mycosphaerella graminicola (Fuckel) Schroter (anamorph: Septoria tritici Roberge in Desmaz.
and reaction to Septoria leaf blotch (caused by Septoria tritici Roberge in Desmaz.
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.
Stadnik and Buchenauer (1999a, 1999b) reported success in field experiments with single applications of BTH for controlling powdery mildew of wheat, but had mixed results against Septoria leaf blotch (caused by Septoria tritici Roberge in Desmaz.
Pat is moderately susceptible to Septoria leaf blotch, similar to Coker 9663 on the basis of a natural infection at Stuttgart, AR, in 2001.
Ok101 is moderately susceptible to Wheat streak mosaic virus, Barley yellow dwarf virus, and Septoria leaf blotch (caused by Septoria tritici Roberge in Desmaz).