back to HYPP Pathology
home page

Mycologia, BASIDIOMYCOTINA, UREDINALES, PUCCINIACEAE .

Crops attacked: barley, .

Black rust,

Identification, Description, Biology, Epidemiology, Treatement, Possible misleading, Images

[R]Description
Elongated, linear, brown to black pustules occur on the leaves, stems and sheaths and are surrounded by frayed epidermis. They mainly show on the sheath, in streaks parallel to the rib.
The glumes can also carry pustules.
Late infections (early summer) cause reduced loss.
Shrivelling and drop in the yield.

[R]Biology
The fungus survives on the autumn straw : black longitudinal pustules cause the splitting of the epidermis of stems and release teliospores.
In spring teliospore germination generates the basidiospores.
Basidiospores only germinate on barberry. On the lower surface of the barberry leaves yellow pustules occur : it is the aecia which will release aeciospores.
The aeciospores infect the cereal leaves and cause urediniospore formation.
In favourable conditions many urediniospore generations succeed each other.
It is only before harvest that the teliospores replace the urediniospores.

[R]Epidemiology
The basidiospores, aeciospores and urediniospores are disseminated by the wind.
In the areas with mild winters the aecian host is not neccesary.
The fungus keeps reproducing through the urediniospores.

[R]Treatement
Use resistant cultivars to the particular dangereous strain in each area.

[R]Possible misleading
.

[R] Images

1. Puccinia graminis , Black rust (BASF)
   Cereal black rust Teliospores of black rust on wheat stems and sheaths.
   
2. Puccinia graminis , Black rust (VIDAL L., INRA)
   Cereal black rust Detail of the stage uredospores (lower surface of winter wheat leaf).
   
3. Puccinia graminis , Black rust (BASF)
   Cereal black rust Teliospore stage of brown rust on a wheat stem.
   
4. (RAYNAL G., INRA)
   Barberry: alternate host (aecidial host) for Cereal black rust.
   
5. Puccinia graminis , Black rust (RAYNAL G., INRA)
   Cereal black rust Cut through a wheat leaf showing an aecidium liberating its aeciospores (light microscope).
   
6. Puccinia graminis , Black rust (RAYNAL G., INRA)
   Cereal black rust Aecium on the leaves of barberry (alternate host to wheat in the black rust development cycle).
   
7. Puccinia graminis , Black rust (BONDOUX P., INRA)
   Cereal black rust Uredospores from wheat black rust as seen through the light microscope.
   

To read this page in French

HYP3 on line : Species (scientific name), Diseases (common names), Glossary, Crops.

back to HYPP Pathology home page