What does the permanent wilting point signify for plants?

The permanent wilting point signifies the critical level of soil moisture at which plants can no longer extract sufficient water to maintain normal physiological functions. At this stage, the soil water is held too tightly by soil particles for plant roots to absorb it, leading to irreversible wilting. When the soil moisture reaches this point, plants experience a severe water deficit, ultimately affecting their health and survival.

Understanding this concept is crucial for greenhouse management, as it informs watering strategies and helps prevent the adverse effects of drought stress on plants. Recognizing the permanent wilting point allows growers to manage irrigation practices effectively, ensuring that plants remain hydrated and healthy throughout their growth periods.