Edema
Return to physiological and nutritional disorders
Edema (Oedema) is caused by the uptake of excessive water by the plant which cannot be transpired by the leaves. It will show up as small blister-like areas, which eventually can turn into sunken corky lesions. Edema is characteristic of plants which are overwatered, but also occurs in plants grown under conditions of normal water status but low transpiration (low light, low temperatures). Because many cole crops are planted during periods of cool temperatures they may be subject to edema.
Edema on cabbage leaves
(Photo: Hunt Sanders, University of Georgia, Bugwood.org)
Closeup of edema on cabbage leaves
(Photo: David Langston, University of Georgia, Bugwood.org)
Management:
- Edema can be limited by growing transplants under low humidity and high-light conditions and not watering excessively.
- In the field growers can attempt to reduce excessive irrigations though humidity, temperature, and light levels are impossible to control.
