Plants and any from of living organisms cannot live without water, since water is
the most important constituent about 80 to 90% of most plant cell. Role of water in crop and crop production can be grouped as
A) Physiological importance
• The plant system itself contains about 90% of water
• Amount of water varies in different parts of plant as follows
• Apical portion of root and shoot >90%
• Stem, leaves and fruits – 70 – 90%
• Woods – 50 – 60%
• Matured parts – 15 – 20%
• Freshly harvested grains – 15 – 20%
• It acts as base material for all metabolic activities. All metabolic or biochemical
reactions in plant system need water.
• It plays an important role in respiration and transpiration
• It plays an important role in photosynthesis
• It activates germination and plays in important role in plant metabolism for
vegetative and reproductive growth
• It serves as a solvent in soil for plant nutrients
• It also acts as a carrier of plant nutrients from soil to plant system
• It maintains plant temperature through transpiration
• It helps to keep the plant erect by maintaining plant’s turgidity
• It helps to transport metabolites from source to sink
B) Ecological Importance
• It helps to maintain soil temperature
It helps to maintain salt balance
• It reduces salinity and alkalinity
• It influences weed growth
• It influences atmospheric weather
• It helps the beneficial microbes
• It influences the pest and diseases
• It supports human and animal life
• It helps for land preparation like ploughing, puddling, etc.,
• It helps to increase the efficiency of cultural operations like weeding, fertilizer
application etc., by providing optimum condition.
