Vapor Pressure Deficit Effects on Plant Growth and Physiology

Vapour pressure deficit (VPD) describes the difference between the moisture present in the air and the maximum moisture the air can hold at a given temperature. It represents the primary driving force for water movement from soil, through plants, and into the atmosphere. As VPD rises, the evaporative demand increases, influencing stomatal aperture, transpiration rate and water transport within the xylem. These processes in turn regulate photosynthetic carbon assimilation, leaf cooling and nutrient uptake. Persistent high VPD can induce water stress, leading to reduced leaf expansion, altered leaf anatomy and diminished growth. Conversely, excessively low VPD may limit transpiration and nutrient flow, affecting gas exchange and humidity control. Understanding the balance of VPD is therefore crucial for optimising plant water use efficiency, enhancing productivity in both field crops and controlled-environment agriculture, and mitigating the impacts of climate change on global food security.

Research from Nature Portfolio

Recent studies have explored manipulation of VPD in controlled environments. One investigation examined tomato plants under contrasting VPD gradients, demonstrating that reduced VPD lowers the driving force for water transport, curbs transpiration and leaf desiccation and sustains stomatal opening and photosynthesis. This led to significant gains in biomass, fruit yield and irrigation water use efficiency, indicating that precise VPD control can bolster greenhouse productivity. Another study assessed the interaction between VPD and atmospheric CO₂ enrichment in greenhouse-grown tomato. Lowering VPD alleviated water stress and expanded leaf gas exchange area, while elevated CO₂ further enhanced photosynthetic rate and water use efficiency under reduced VPD conditions. These findings highlight the synergistic potential of concurrently optimising VPD and CO₂ to improve plant performance under semi-arid conditions.

Vapor Pressure Deficit Effects on Plant Growth and Physiology publication trend

The graph below shows the total number of articles in vapor pressure deficit effects on plant growth and physiology across all publications each year (not limited to Nature Index journals).

Technical terms

Vapour Pressure Deficit (VPD): The difference between the saturation vapour pressure and the actual vapour pressure at a given temperature, driving transpiration.

Stomatal Conductance: The rate of gas exchange through leaf stomata, determining CO₂ entry for photosynthesis and water vapour loss.

Hydraulic Conductance: A measure of the efficiency with which water moves through plant tissues from roots to leaves.

Transpiration: The process by which water evaporates from plant surfaces, primarily through stomata, contributing to nutrient transport and cooling.

Water Use Efficiency (WUE): The ratio of biomass produced or carbon assimilated to the volume of water transpired by the plant.

References

1. Vapour pressure deficit control in relation to water transport and water productivity in greenhouse tomato production during summer. Scientific Reports (2017).
2. Coordination between vapor pressure deficit and CO2 on the regulation of photosynthesis and productivity in greenhouse tomato production. Scientific Reports (2019).
3. Minimizing VPD Fluctuations Maintains Higher Stomatal Conductance and Photosynthesis, Resulting in Improvement of Plant Growth in Lettuce. Frontiers in Plant Science (2021).
4. Integration of high-throughput phenotyping with anatomical traits of leaves to help understanding lettuce acclimation to a changing environment. Planta (2022).
5. Regulating Vapor Pressure Deficit and Soil Moisture Improves Tomato and Cucumber Plant Growth and Water Productivity in the Greenhouse. Horticulturae (2022).