Articles
PLANT RESPONSES AND ADAPTATION TO WATER ISSUES IN THE GREENHOUSE ENVIRONMENT
Article number
458_23
Pages
201 – 206
Language
Abstract
Water quantity and quality influence the yield and quality of greenhouse crops in many different ways.
The water vapour pressure deficit (VPD) of the greenhouse atmosphere has a direct effect upon the rate of evaporation of water from leaves and can affect the incidence of disease.
When grown at high atmospheric humidity for long periods, the leaves of tomato are reduced in size and demonstrate symptoms of calcium deficiency; responses that adversely affect yield and are related to a localised lack of calcium induced by reduced transpiration.
The quantity and quality of water supplied to the root system is of great importance in the greenhouse environment.
Ideally, the uptake of water by the root system should match the requirements of the above-ground parts of the plant at all times, but this ideal is rarely achieved.
When water is withheld from the root environment of tomatoes, overall fruit yields and individual fruit sizes are reduced, while the incidence of blossom-end rot is increased.
The latter disorder is also due to a localised lack of calcium.
In contrast to the deleterious effects of withholding water, the dry matter content, acidity and sugar content of tomato fruits are increased.
Many of these changes will also occur if the electrical conductivity (EC) of the irrigation solution is raised.
Lack of oxygen around the roots and low solution temperatures are two further aspects of water quality that have adverse effects on crop production and yet can be avoided.
The need for greenhouse crops that can tolerate water stress and salinity will intensify as supplies of high quality water become more limited and costly.
The water vapour pressure deficit (VPD) of the greenhouse atmosphere has a direct effect upon the rate of evaporation of water from leaves and can affect the incidence of disease.
When grown at high atmospheric humidity for long periods, the leaves of tomato are reduced in size and demonstrate symptoms of calcium deficiency; responses that adversely affect yield and are related to a localised lack of calcium induced by reduced transpiration.
The quantity and quality of water supplied to the root system is of great importance in the greenhouse environment.
Ideally, the uptake of water by the root system should match the requirements of the above-ground parts of the plant at all times, but this ideal is rarely achieved.
When water is withheld from the root environment of tomatoes, overall fruit yields and individual fruit sizes are reduced, while the incidence of blossom-end rot is increased.
The latter disorder is also due to a localised lack of calcium.
In contrast to the deleterious effects of withholding water, the dry matter content, acidity and sugar content of tomato fruits are increased.
Many of these changes will also occur if the electrical conductivity (EC) of the irrigation solution is raised.
Lack of oxygen around the roots and low solution temperatures are two further aspects of water quality that have adverse effects on crop production and yet can be avoided.
The need for greenhouse crops that can tolerate water stress and salinity will intensify as supplies of high quality water become more limited and costly.
Authors
K.E. Cockshull
Keywords
Online Articles (54)