Oedema
Class: Physiological disorders
Common Name
Oedema and edema
Potential Hosts
All plants can be affected by oedema
In short
This disorder occurs mainly during a sudden change of climate when humidity goes up rapidly and temperatures drop quickly. Such a change within a short period of time will result in plants taking up more water than their leaves can transpire. The outcome will be an excess of watery fluid accumulating in the plant tissues.
Symtoms
Formation of numerous small, water-soaked blisters appear mainly along the veins of the undersides of leaves. These blisters will erupt forming brown, corky growths. In time, the leaves may turn yellow and fall off.
In greenhouses, oedema formation can take place within hours.
Control measures
Take actions in order to reduce moisture levels:
*Temporarily lowering the amount of irrigation.
*In closed structures: Improve air circulation, promote drying foliage, and shorten the duration of wetting periods by introducing net curtain vented areas.
Caution and careful notice should be taken when using any plant protection products (insecticides, fungicides, and herbicides). It is the grower’s sole responsibility to keep track of the legal uses and permissions with respect to the laws in their country and destination markets. Always read the instructions written on labels, and in a case of contradiction, work in accordance to the product label. Keep in mind that information written on the label usually applies to local markets. Pest control products intended for organic farming are generally considered to be less effective in comparison to conventional products. When dealing with organic, biologic, and to some extent a small number of conventional chemical products, a complete eradication of a pest or disease will often require several iterations of a specific treatment or combination of treatments.