Water Deficit

Also found in: Dictionary, Thesaurus, Medical, Legal, Financial, Acronyms.

Water Deficit


(biology), the incomplete saturation with water of plant cells, resulting from an intensive water loss by the plant that is not replenished by absorption of water from the soil. A water deficit is usually observed during the hottest hours of the day. The leaves of many plants, such as thorn-apple and pumpkin, lose their turgor at this time and droop. The external appearance of plants with a large amount of mechanical tissue (immortelles) does not change even when they die of water deficit. With the arrival of dry weather one can observe residual water deficit, when the plant cannot make up its lack of water during the night. Water deficit, especially residual water deficit, causes many physiological and biochemical changes in plants. Some plants (certain groups of xerophytes, the so-called euxerophytes) can with-stand a very large water deficit (up to 50-60 percent), while other plants (mesophytes) are harmed by a relatively small water deficit. Since there is no reliable method for determining water deficit, one must sometimes resort to determining the wilting coefficient. For plants that are raised without watering, one determines the amount of water in the soil at the moment when their leaves begin to wilt.


Genkel’, P. A.“Ustoichivost’ rastenii k zasukhe i puti ee povysheniia.” Tr. In-ta fiziologii rastenii im. K. A. Timiriazeva, 1946, vol. 5, part 1.
Litvinov, L. S. O pochvennoi zasukhe i ustoichivosti k nei rastenii. L’vov, 1951.
Zholkevich, V. N. Energetika dykhaniia vysshykh rastenii v usloviiakh vodnogo defitsita. Moscow, 1968.


Mentioned in ?
References in periodicals archive ?
The value of 80% of Cp represented plants kept in pots without water deficit, while value of 20% of Cp represented plants kept in severe water deficit.
Increased content of intracellular proline thus increases the plant's ability to survive under water deficit (Taylor 1996).
Young plants of Brazilian mahogany (Swietenia macrophylla King), cultivated in soil water contents close to the field capacity, also recorded higher values of plant height (116%), leaf area (200%) and stem diameter (50% ) when compared to plants in water deficit (Cordeiro et al.
The increase in root length when plants are subjected to moderate water deficits is due to the need for the root system to be able to absorb water at greater depths (Avila et al.
2008) declared that PGPR elevated proline content of lettuce under water deficit conditions, which was an important indicator for drought stress alleviation.
stated that process of seed formation in maize determines by leaves photosynthesis, amount of sugars, starch, Abscisic acid and cytokinin; hence, water deficit at pollination stage via impact on these phenomena caused to reduction in seed formation at bottom of the ear [35].
According to Blue Gold, Lebanon could reverse the water deficit to a surplus generating more than $600 million in revenues by 2020.
Summary: Water experts in Egypt say there is already water deficit in country due to exploding population.
To combat a yearly water deficit that could reach 400 billion [m.
The two-day seminar aims at highlighting the role and uses of fog water in arid and semi-arid areas, exchange of experiences and ideas in fog collecting field due to the importance of fog water in contributing to reducing the water deficit and enhancing underground water feeding.