Mycologia, DEUTEROMYCOTINA, HYPHOMYCETALES, MONILIACEAE .
Identification, Description, Biology, Epidemiology, Treatement, Possible misleading, Images
Interveinal chlorosis of the leaves ; leaf tissues turning yellow, then brown (necrosis) ; it is to be noted that the symptoms on leaves are characteristic. On the stem a continuous black stripe appears and extends from the base upwards to a certain height, sometimes to the capitulum, still it never entirely surrounds the stem.
Microsclerotia are present under the epidermis throughout this black stripe. The microsclerotia area does not penetrate the medullar tissues of the stem. On the capitulum the achenes are smaller due to early drying of the plant.
The affected plants can be recognized in the population by their early maturity.
This soilborne fungus is associated with a field ; it rests in the crop debris incorporated to the soil. The mycelium attacks the roots, then the colonization is systemic.
Often, the action of this fungus cannot be distinguished from that of V. dahliae .
They can be differenciated only through isolation.
An average temperature of 21 to 24 °C. favours V. albo-atrum .
Incorporating the plant debris deep down in the soil.
This disease is not particularly important. A treatment is often not justified.
Macrophomina phaseoli but here there is no sclerotium inside the medulla and with V. albo-atrum which is frequently associated with V. dahliae .
HYP3 on line : Species (scientific name), Diseases (common names), Glossary, Crops.