dcsimg

Peronospora destructor

provided by wikipedia EN

Peronospora destructor is a plant pathogen. It causes downy mildew on leaves of cultivated and wild Allium. Allium cepa (onion and shallot) is most often affected, while Allium schoenoprasum (chives) and Allium porrum (leek) are only occasionally affected.

Downy mildew is a major disease of onion.[1] The pathogen persists as mycelium systemically infecting onion bulbs, but is not known to be transmitted in onion seed. The pathogen can persist in the soil for several years as oospores. Systemically infected plants are dwarfed and pale green. Under moist conditions, the pathogen sporulates on the affected tissues and spreads to other plants, on the leaves and stalks of which it forms greyish-violet local lesions. Infected leaves are often entirely killed. Critical periods for infection have been determined.[2] Infected crops yield poorly, and produce distorted bulbs. Control is by crop rotation (at least 3 years between successive onion crops), use of healthy bulbs for planting (heat treatment has been used to eliminate the pathogen from bulbs), fungicide treatment of the bulbs for planting, and fungicide sprays of the foliage if downy mildew infection is nevertheless observed.[3]

References

  1. ^ Smith IM, Dunez J, Lelliott RA, Phillips DH, Archer SA, eds. (1988). European Handbook of Plant Diseases. Blackwell Scientific Publications. ISBN 978-0-632-01222-0.
  2. ^ Virányi F (1981). Downy mildew of onion. In The Downy Mildews (ed. DM Spencer), pp. 461-472. Academic Press.
  3. ^ OEPP/EPPO (2000). Allium crops. EPPO Standards PP2 Good Plant Protection Practice, no. 4. European and Mediterranean Plant Protection Organization.
license
cc-by-sa-3.0
copyright
Wikipedia authors and editors
original
visit source
partner site
wikipedia EN

Peronospora destructor: Brief Summary

provided by wikipedia EN

Peronospora destructor is a plant pathogen. It causes downy mildew on leaves of cultivated and wild Allium. Allium cepa (onion and shallot) is most often affected, while Allium schoenoprasum (chives) and Allium porrum (leek) are only occasionally affected.

Downy mildew is a major disease of onion. The pathogen persists as mycelium systemically infecting onion bulbs, but is not known to be transmitted in onion seed. The pathogen can persist in the soil for several years as oospores. Systemically infected plants are dwarfed and pale green. Under moist conditions, the pathogen sporulates on the affected tissues and spreads to other plants, on the leaves and stalks of which it forms greyish-violet local lesions. Infected leaves are often entirely killed. Critical periods for infection have been determined. Infected crops yield poorly, and produce distorted bulbs. Control is by crop rotation (at least 3 years between successive onion crops), use of healthy bulbs for planting (heat treatment has been used to eliminate the pathogen from bulbs), fungicide treatment of the bulbs for planting, and fungicide sprays of the foliage if downy mildew infection is nevertheless observed.

license
cc-by-sa-3.0
copyright
Wikipedia authors and editors
original
visit source
partner site
wikipedia EN