back to HYPP Pathology
home page

Mycologia, DEUTEROMYCOTINA, MELANCONIALES, MELANCONIACEAE .

Crops attacked: lucerne .

Lucerne anthracnose

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

[R]Description
In the field, the affected area show wilted stems, isolated or in foci.
At the base of the stems in isolated plants, pale brown elongated lesion occur, with dark margins and a greyish center covered by little brown spots.
The lesion can girdle the stem which dries up and crouches at the top.
In summer the whole plant dessicates and wilts.

[R]Biology
The fungus survives as mycelium on plant debris or on the collar of infected lucerne still in the field.
Conidia form at the base of the stem in a gel which covers the mycelial stromas (acervuli).

[R]Epidemiology
The acervuli occur in conditions of high relative humidity at about 20 °C.
Conidia are spread by the rain.
Conidial germination takes 6 to 8 hours when the temperature is about 25 °C.
Cycles of secondary infection may occur if the conditions (temperature and humidity) remain favourable.

[R]Treatement
Early pruning is recommended to reduce the humidity in the crop.
Use resistant cultivars.

[R]Possible misleading
The wilting symptoms can be mistaken with those of Sclerotinia trifoliorum , Verticillium albo-atrum , Fusarium spp. and Rhizoctonia violacea .

[R] Images

1. Colletotrichum trifolii , Lucerne anthracnose (POINSO B., INRA)
   Lucerne anthracnose Colletotrichum trifolii wilt on lucerne isolated plants.
   
2. Colletotrichum trifolii , Lucerne anthracnose (VEGH I., INRA)
   Lucerne anthracnose Elongated spots of Colletotrichum trifolii on lucerne stems.
   

To read this page in French

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

back to HYPP Pathology home page