Moisture stress occurs when the water in a plant's cells is reduced to less than normal levels. This can occur because of a lack of water in the plant's root zone, higher rates of transpiration

Transpiration

Transpiration is a process similar to evaporation. It is a part of the water cycle, and it is the loss of water vapor from parts of plants , especially in leaves but also in stems, flowers and roots. Leaf surfaces are dotted with openings which are collectively called stomata, and in most plants...

 than the rate of moisture uptake by the roots, for example, because of an inability to absorb water due to a high salt

Salt

In chemistry, salts are ionic compounds that result from the neutralization reaction of an acid and a base. They are composed of cations and anions so that the product is electrically neutral...

 content in the soil water or loss of roots due to transplantation. Moisture stress is more strongly related to water potential

Water potential

Water potential is the potential energy of water per unit volume relative to pure water in reference conditions. Water potential quantifies the tendency of water to move from one area to another due to osmosis, gravity, mechanical pressure, or matrix effects such as surface tension...

 than it is to water content

Water content

Water content or moisture content is the quantity of water contained in a material, such as soil , rock, ceramics, fruit, or wood. Water content is used in a wide range of scientific and technical areas, and is expressed as a ratio, which can range from 0 to the value of the materials' porosity at...

.

See also

• Nonlimiting water range
  Nonlimiting water range
  The Non-limiting water range represents the range of water content in the soil where limitations to plant growth are minimal...
  
  
• Permanent wilting point
  Permanent wilting point
  Permanent wilting point or wilting point is defined as the minimal point of soil moisture the plant requires not to wilt. If moisture decreases to this or any lower point a plant wilts and can no longer recover its turgidity when placed in a saturated atmosphere for 12 hours...
  
  
• Soil plant atmosphere continuum
  Soil plant atmosphere continuum
  The Soil-Plant-Atmosphere Continuum is the pathway for water moving from soil through plants to the atmosphere.The transport of water along this pathway occurs in components, variously defined among scientific disciplines:...