Excerpt from the report: The weight of growing crops is composed mostly of water. Flow of water into the roots and out through the leaves is normal for most crops in carrying on growth processes. If water in the plant becomes deficient, either by excessive evaporation or by limited availability in the soil, the rate at which the plant can grow is decreased. Many factors control growth, such as nutritional elements in the soil and physical conditions in the whole plant environment, but water status within the plant is always a major factor and is often limiting. Soil salinity directly affects the availability of water to plants.