Fandom

WikiGardener

Downy mildew

712pages on
this wiki
Add New Page
Talk0 Share
Downy mildew
Grape Downy Powdery Mildew
A grape leaf showing downy mildew and powdery mildew
Scientific Classification
Kingdom: Chromalveolata
Phylum: Heterokontophyta
Class: Oomycetes
Order: Peronosporales
Family: Peronosporaceae

Downy mildew refers to any of several types of oomycete microbes of the Peronosporaceae family that are a particular problem for growers of brassicas, grapes and vine-type vegetables.

Cucurbit downy mildew (caused by Pseudoperonospora cubensis) is specific to cucurbits (e.g. pumpkin, squash, courgette). The disease is one of the most important diseases of cucurbits worldwide.

A serious disease in cool, damp seasons.

SymptomsEdit

The initial symptoms of downy mildew appear on leaves as light green to yellow spots, then as it develops it becomes a downy grey mould. Leaves slowly die back and shrivel from the tips.[1] Onion bulbs infected become soft and are not suitable for storage.

TreatmentEdit

None. Should the disease be confirmed on site, immediately dispose of diseased material in sealed bags or bins and arrange for it to be destroyed.[2]

PreventionEdit

Good practice[2]:

  • Try to ensure any starting plant material is disease free.
  • Provide good air circulation and ventilation in glasshouses.
  • Try to avoid long periods of high humidity and leaf wetness.
  • Avoid watering crops late in the day.
  • Apply a routine preventative fungicide programme to minimise disease risk, especially during periods when environmental conditions are favourable for downy mildew infection.
  • Practice good nursery hygiene by cleaning up plant debris between crops and at the end of the season and use appropriate disinfectants.

ExamplesEdit

ReferencesEdit

  1. Hessayon, D.G. (2009). The Vegetable & Herb Expert. Transworld Publishers, London. p. 75. ISBN 9780903505468
  2. a b McPherson, M. and Brough, W. (2009) "Good Horticultural Practice for the Prevention and Control of Impatiens Downy Mildew (Plasmopara obducens)". Agriculture and Horticultural Development Board. Retrieved 2010-07-17.
This page uses Creative Commons Licensed content from Wikipedia (view authors).

Ad blocker interference detected!


Wikia is a free-to-use site that makes money from advertising. We have a modified experience for viewers using ad blockers

Wikia is not accessible if you’ve made further modifications. Remove the custom ad blocker rule(s) and the page will load as expected.