Mycologia, FUNGI IMPERFECTI, AGONOMYCETALES .
Identification, Description, Biology, Epidemiology, Treatement, Possible misleading, Images
Serious and frequent.
White cotony mycelium at the base of the bulbs and on the roots ; formation of little black spheric sclerotia in large numbers (0.2 - 0.5 mm diameter).
The primary sites of infection are due to mycelial hyphae produced by sclerotia under the action of specific agents generated by the roots of the host plants.
Secondary infection from plant to plant may occur such as the intensive infection in onions.
Yellowing and wilting of the older leaves which fall.
The fungus persists during winter burried in the soil as sclerotia.
Long survival (15 years) of sclerotia in the soil.
Optimum temperature : 10 -20 °C.
The growth of this fungus is restricted by higher temperatures.
Avoid the too frequent return of crops of the Allium family in the rotation.
HYP3 on line : Species (scientific name), Diseases (common names), Glossary, Crops.