wiltingpointin

Wilting point, sometimes described in literature as the wilting point in soil moisture terms, is the moisture threshold at which plants begin to wilt due to water deficit. It is most precisely associated with the soil water potential at which plant cells lose turgor pressure, leading to visible wilting. In strict terms, wilting can be reversible with rehydration, while the permanent wilting point (PWP) is the threshold below which recovery is not possible.

Measurement and variability vary by method and context. The wilting point is often derived from soil moisture characteristic curves or direct measurements of soil water potential using tensiometers, pressure plates, or other instruments. Values differ by plant species and soil texture. For many crops, wilting occurs around roughly -0.8 to -1.5 megapascals (MPa), but the corresponding volumetric water content depends on soil porosity and structure. Fine-textured soils may hold water more tightly, shifting the practical moisture content associated with wilting.

Relation to available water is central to irrigation planning. The available water capacity of a soil is the difference between field capacity and the wilting (or permanent wilting) point. When soil moisture drops toward the wilting point, plants experience stress and reduced growth; at or below the permanent wilting point, most plants cannot recover after rehydration. Understanding the wilting point helps in scheduling irrigation to balance plant needs against water use efficiency and drainage considerations. The concept varies with species and soil characteristics, and is a key component of soil–plant–water relations.