How to Calculate Water Loss in Plants

Water loss in plants is a vital factor that determines the plant’s growth and development. Measuring the water loss accurately can help in understanding the plant’s physiology, water-use efficiency, and response to environmental changes. This article will discuss how to calculate water loss in plants accurately.

Methods to Measure Water Loss

There are various methods available to measure water loss in plants. Some common methods include:

Gravimetric method: This method involves weighing a plant before and after the water loss period to determine the amount of water lost.

Pressure bomb method: This method measures the pressure required to force sap from a detached leaf, which is an indirect measure of plant water status.

Infrared gas analyzer method: This method measures the change in water vapor concentration in a closed system while the plant transpires.

Gravimetric Method

The gravimetric method is simple, precise, and widely used for measuring water loss in plants. The following steps are used to calculate water loss using the gravimetric method:

Select a plant sample and remove excess water from the surface using absorbent paper.

Weigh the plant sample and record the weight as W₀.

1.

2.

The water loss or transpiration rate can be calculated using the following formula:

Transpiration rate = (W₁ – W₂)/(W₁ – W₀)

Pressure Bomb Method

The pressure bomb method is another popular method used to measure water loss in plants. The following steps are used to calculate water loss using the pressure bomb method:

Select a plant sample and cut a leaf from the plant.

The water loss or transpiration rate can be calculated using the following formula:

Transpiration rate = collected sap weight/leaf area x pressure

Infrared Gas Analyzer Method

The infrared gas analyzer (IRGA) method is used to measure the water vapor concentration in a closed system. The following steps are used to calculate water loss using the IRGA method:

0) and the volume of the air inside the container (V₀).

1) and the air volume inside the container (V₁).

The water loss or transpiration rate can be calculated using the following formula:

Transpiration rate = (C₀ – C₁) x V₁/V₀

Conclusion

Measuring water loss in plants is essential for understanding the plant’s physiology, water-use efficiency, and response to environmental changes. The gravimetric, pressure bomb, and IRGA methods are commonly used to measure water loss in plants. By using these methods, researchers can accurately calculate the water loss and estimate the plant’s water use and efficiency in different environmental conditions.