1. What is Vapor Pressure Deficit (VPD)?

Vapor Pressure Deficit (VPD) is the difference between the amount of moisture in the air and how much moisture the air can hold when it's saturated. It's a key metric in plant growth environments as it affects transpiration rates.

2. How Does the Aroya VPD Calculator Work?

The calculator uses the Aroya VPD equation:

Where:

• \( SVP \) — Saturation vapor pressure (kPa)
• \( RH \) — Relative humidity (%)

Explanation: The equation calculates the difference between the water vapor pressure at saturation and the actual water vapor pressure in the air.

3. Importance of VPD Calculation

Details: VPD is crucial for optimizing plant growth conditions. It helps maintain the right balance between humidity and temperature to ensure proper transpiration and nutrient uptake.

4. Using the Calculator

Tips: Enter SVP in kPa and RH as a percentage (0-100%). Both values must be valid (SVP > 0, RH between 0-100).

5. Frequently Asked Questions (FAQ)

Q1: What is the ideal VPD range for plants?
A: Optimal VPD ranges vary by plant species and growth stage, but generally 0.8-1.2 kPa is good for vegetative growth and 1.0-1.5 kPa for flowering.

Q2: How does temperature affect VPD?
A: Higher temperatures increase SVP, which can increase VPD if humidity doesn't adjust accordingly.

Q3: Why use Aroya's VPD calculation?
A: Aroya's formula provides a simple yet accurate way to calculate VPD for horticultural applications.

Q4: Can VPD be too high or too low?
A: Yes, both extremes can stress plants - too high causes excessive transpiration, too low can lead to poor nutrient uptake.

Q5: How often should VPD be monitored?
A: In controlled environments, continuous monitoring is ideal as VPD can fluctuate with temperature and humidity changes.