VPD Explained
Vapor Pressure Deficit (VPD) is a critical concept in horticulture that refers to the difference between the amount of moisture in the air and the maximum amount the air can hold when saturated. It's a measure of how 'thirsty' the air is for water, which directly affects plant transpiration and growth.VPD is calculated using temperature and relative humidity. Temperature plays a significant role in this process because warm air can hold more moisture than cool air. As the temperature rises, the air's capacity to hold water increases, leading to a higher potential VPD if the relative humidity doesn't also rise. When VPD is low, the air is humid, and plants transpire less. Conversely, high VPD means the air is dry, causing plants to transpire more. Proper VPD management ensures plants maintain optimal water uptake and nutrient transport, crucial for healthy growth.Managing VPD is essential for controlling plant stress and optimizing growth conditions. If VPD is too high, plants can lose water faster than they can absorb it, leading to wilting and reduced growth. Too low VPD can result in inadequate transpiration, causing poor nutrient uptake and increased risk of fungal diseases. By maintaining the ideal VPD, growers can ensure robust growth, fewer diseases, and higher produce quality.VPD Calculator
10°
11°
12°
13°
14°
15°
16°
17°
18°
19°
20°
21°
22°
23°
24°
25°
26°
27°
28°
29°
30°
31°
32°
33°
34°
35°
36°
37°
38°
39°
40°
41°
42°
43°
44°
45°
100%
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
98%
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
96%
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
94%
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
92%
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.2
0.2
0.2
0.2
0.2
90%
0
0
0
0
0
0
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.3
0.3
0.3
0.3
0.3
0.4
0.4
0.4
88%
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.3
0.3
0.3
0.3
0.3
0.3
0.4
0.4
0.4
0.4
0.5
0.5
0.5
0.6
0.6
86%
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.3
0.3
0.3
0.3
0.3
0.4
0.4
0.4
0.4
0.5
0.5
0.5
0.6
0.6
0.6
0.7
0.7
0.7
0.8
84%
0.1
0.1
0.1
0.1
0.1
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.3
0.3
0.3
0.3
0.3
0.4
0.4
0.4
0.4
0.5
0.5
0.5
0.6
0.6
0.6
0.7
0.7
0.7
0.8
0.8
0.9
0.9
1
82%
0.1
0.1
0.1
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.3
0.3
0.3
0.3
0.3
0.4
0.4
0.4
0.4
0.5
0.5
0.5
0.6
0.6
0.6
0.7
0.7
0.7
0.8
0.8
0.9
0.9
1
1.1
1.1
1.2
80%
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.3
0.3
0.3
0.3
0.3
0.3
0.4
0.4
0.4
0.5
0.5
0.5
0.5
0.6
0.6
0.7
0.7
0.7
0.8
0.8
0.9
0.9
1
1
1.1
1.2
1.2
1.3
1.4
78%
0.2
0.2
0.2
0.2
0.2
0.3
0.3
0.3
0.3
0.3
0.4
0.4
0.4
0.4
0.5
0.5
0.5
0.6
0.6
0.6
0.7
0.7
0.7
0.8
0.8
0.9
0.9
1
1.1
1.1
1.2
1.3
1.3
1.4
1.5
1.6
76%
0.2
0.2
0.2
0.3
0.3
0.3
0.3
0.3
0.4
0.4
0.4
0.4
0.5
0.5
0.5
0.5
0.6
0.6
0.7
0.7
0.7
0.8
0.8
0.9
0.9
1
1.1
1.1
1.2
1.3
1.3
1.4
1.5
1.6
1.7
1.7
74%
0.2
0.2
0.3
0.3
0.3
0.3
0.3
0.4
0.4
0.4
0.4
0.5
0.5
0.5
0.6
0.6
0.7
0.7
0.7
0.8
0.8
0.9
0.9
1
1.1
1.1
1.2
1.2
1.3
1.4
1.5
1.6
1.6
1.7
1.8
1.9
72%
0.3
0.3
0.3
0.3
0.3
0.4
0.4
0.4
0.4
0.5
0.5
0.5
0.6
0.6
0.6
0.7
0.7
0.8
0.8
0.9
0.9
1
1
1.1
1.2
1.2
1.3
1.4
1.5
1.5
1.6
1.7
1.8
1.9
2
2.1
70%
0.3
0.3
0.3
0.3
0.4
0.4
0.4
0.4
0.5
0.5
0.5
0.6
0.6
0.7
0.7
0.7
0.8
0.8
0.9
0.9
1
1.1
1.1
1.2
1.3
1.3
1.4
1.5
1.6
1.7
1.8
1.9
2
2.1
2.2
2.3
68%
0.3
0.3
0.3
0.4
0.4
0.4
0.5
0.5
0.5
0.6
0.6
0.6
0.7
0.7
0.8
0.8
0.9
0.9
1
1
1.1
1.2
1.2
1.3
1.4
1.5
1.5
1.6
1.7
1.8
1.9
2
2.1
2.3
2.4
2.5
66%
0.3
0.3
0.4
0.4
0.4
0.5
0.5
0.5
0.6
0.6
0.6
0.7
0.7
0.8
0.8
0.9
0.9
1
1
1.1
1.2
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
2
2.1
2.2
2.3
2.4
2.6
2.7
64%
0.4
0.4
0.4
0.4
0.5
0.5
0.5
0.6
0.6
0.6
0.7
0.7
0.8
0.8
0.9
0.9
1
1
1.1
1.2
1.3
1.3
1.4
1.5
1.6
1.7
1.8
1.9
2
2.1
2.2
2.3
2.5
2.6
2.7
2.9
62%
0.4
0.4
0.4
0.5
0.5
0.5
0.6
0.6
0.6
0.7
0.7
0.8
0.8
0.9
0.9
1
1.1
1.1
1.2
1.3
1.3
1.4
1.5
1.6
1.7
1.8
1.9
2
2.1
2.2
2.4
2.5
2.6
2.8
2.9
3.1
60%
0.4
0.4
0.5
0.5
0.5
0.6
0.6
0.6
0.7
0.7
0.8
0.8
0.9
0.9
1
1.1
1.1
1.2
1.3
1.3
1.4
1.5
1.6
1.7
1.8
1.9
2
2.1
2.2
2.4
2.5
2.7
2.8
3
3.1
3.3
58%
0.4
0.5
0.5
0.5
0.6
0.6
0.6
0.7
0.7
0.8
0.8
0.9
0.9
1
1.1
1.1
1.2
1.3
1.3
1.4
1.5
1.6
1.7
1.8
1.9
2
2.1
2.3
2.4
2.5
2.7
2.8
3
3.1
3.3
3.5
56%
0.4
0.5
0.5
0.5
0.6
0.6
0.7
0.7
0.8
0.8
0.9
0.9
1
1
1.1
1.2
1.3
1.3
1.4
1.5
1.6
1.7
1.8
1.9
2
2.1
2.2
2.4
2.5
2.7
2.8
3
3.1
3.3
3.5
3.7
54%
0.5
0.5
0.5
0.6
0.6
0.7
0.7
0.8
0.8
0.9
0.9
1
1
1.1
1.2
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
2
2.1
2.2
2.4
2.5
2.6
2.8
3
3.1
3.3
3.5
3.7
3.9
52%
0.5
0.5
0.6
0.6
0.7
0.7
0.7
0.8
0.8
0.9
1
1
1.1
1.2
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
2
2.1
2.2
2.4
2.5
2.6
2.8
2.9
3.1
3.3
3.5
3.6
3.8
4
50%
0.5
0.6
0.6
0.6
0.7
0.7
0.8
0.8
0.9
0.9
1
1.1
1.1
1.2
1.3
1.4
1.5
1.5
1.6
1.7
1.8
2
2.1
2.2
2.3
2.5
2.6
2.8
2.9
3.1
3.2
3.4
3.6
3.8
4
4.2
48%
0.5
0.6
0.6
0.7
0.7
0.8
0.8
0.9
0.9
1
1.1
1.1
1.2
1.3
1.4
1.4
1.5
1.6
1.7
1.8
1.9
2.1
2.2
2.3
2.4
2.6
2.7
2.9
3
3.2
3.4
3.6
3.8
4
4.2
4.4
46%
0.6
0.6
0.7
0.7
0.7
0.8
0.9
0.9
1
1
1.1
1.2
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
2
2.1
2.3
2.4
2.5
2.7
2.8
3
3.2
3.4
3.5
3.7
3.9
4.2
4.4
4.6
44%
0.6
0.6
0.7
0.7
0.8
0.8
0.9
0.9
1
1.1
1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
2
2.1
2.2
2.4
2.5
2.6
2.8
3
3.1
3.3
3.5
3.7
3.9
4.1
4.3
4.6
4.8
42%
0.6
0.7
0.7
0.8
0.8
0.9
0.9
1
1.1
1.1
1.2
1.3
1.4
1.4
1.5
1.6
1.7
1.8
1.9
2.1
2.2
2.3
2.5
2.6
2.8
2.9
3.1
3.3
3.4
3.6
3.8
4.1
4.3
4.5
4.7
5
40%
0.6
0.7
0.7
0.8
0.8
0.9
1
1
1.1
1.2
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
2
2.1
2.3
2.4
2.6
2.7
2.9
3
3.2
3.4
3.6
3.8
4
4.2
4.4
4.7
4.9
5.2
38%
0.7
0.7
0.8
0.8
0.9
0.9
1
1.1
1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
2
2.1
2.2
2.4
2.5
2.6
2.8
3
3.1
3.3
3.5
3.7
3.9
4.1
4.4
4.6
4.9
5.1
5.4
36%
0.7
0.7
0.8
0.8
0.9
1
1
1.1
1.2
1.3
1.3
1.4
1.5
1.6
1.7
1.8
1.9
2
2.2
2.3
2.4
2.6
2.7
2.9
3.1
3.3
3.4
3.6
3.8
4.1
4.3
4.5
4.8
5
5.3
5.6
34%
0.7
0.8
0.8
0.9
0.9
1
1.1
1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
2
2.1
2.2
2.4
2.5
2.7
2.8
3
3.2
3.4
3.6
3.8
4
4.2
4.4
4.7
4.9
5.2
5.5
5.8
32%
0.7
0.8
0.9
0.9
1
1
1.1
1.2
1.3
1.3
1.4
1.5
1.6
1.7
1.8
1.9
2.1
2.2
2.3
2.5
2.6
2.8
2.9
3.1
3.3
3.5
3.7
3.9
4.1
4.3
4.6
4.8
5.1
5.4
5.7
6
30%
0.8
0.8
0.9
0.9
1
1.1
1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
2
2.1
2.3
2.4
2.5
2.7
2.9
3
3.2
3.4
3.6
3.8
4
4.2
4.5
4.7
5
5.3
5.5
5.8
6.2
28%
0.8
0.8
0.9
1
1
1.1
1.2
1.3
1.3
1.4
1.5
1.6
1.7
1.8
1.9
2.1
2.2
2.3
2.5
2.6
2.8
2.9
3.1
3.3
3.5
3.7
3.9
4.1
4.4
4.6
4.9
5.1
5.4
5.7
6
6.3
26%
0.8
0.9
0.9
1
1.1
1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
2
2.1
2.3
2.4
2.6
2.7
2.9
3
3.2
3.4
3.6
3.8
4
4.3
4.5
4.8
5
5.3
5.6
5.9
6.2
6.5
24%
0.8
0.9
1
1
1.1
1.2
1.3
1.3
1.4
1.5
1.6
1.7
1.8
1.9
2.1
2.2
2.3
2.5
2.6
2.8
3
3.1
3.3
3.5
3.7
3.9
4.2
4.4
4.6
4.9
5.2
5.4
5.7
6.1
6.4
6.7
22%
0.9
0.9
1
1.1
1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
2
2.1
2.3
2.4
2.5
2.7
2.9
3
3.2
3.4
3.6
3.8
4
4.3
4.5
4.8
5
5.3
5.6
5.9
6.2
6.6
6.9
20%
0.9
1
1
1.1
1.2
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
2.1
2.2
2.3
2.5
2.6
2.8
2.9
3.1
3.3
3.5
3.7
3.9
4.2
4.4
4.6
4.9
5.2
5.5
5.8
6.1
6.4
6.8
7.1
18%
0.9
1
1
1.1
1.2
1.3
1.4
1.5
1.5
1.6
1.8
1.9
2
2.1
2.2
2.4
2.5
2.7
2.9
3
3.2
3.4
3.6
3.8
4
4.3
4.5
4.8
5
5.3
5.6
5.9
6.2
6.6
6.9
7.3
16%
0.9
1
1.1
1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
2
2.2
2.3
2.5
2.6
2.8
2.9
3.1
3.3
3.5
3.7
3.9
4.1
4.4
4.6
4.9
5.2
5.5
5.8
6.1
6.4
6.8
7.1
7.5
14%
1
1
1.1
1.2
1.3
1.3
1.4
1.5
1.6
1.7
1.8
2
2.1
2.2
2.4
2.5
2.7
2.8
3
3.2
3.4
3.6
3.8
4
4.2
4.5
4.7
5
5.3
5.6
5.9
6.2
6.6
6.9
7.3
7.7
12%
1
1.1
1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
2
2.1
2.3
2.4
2.6
2.7
2.9
3.1
3.3
3.5
3.7
3.9
4.1
4.3
4.6
4.9
5.1
5.4
5.7
6.1
6.4
6.7
7.1
7.5
7.9
10%
1
1.1
1.2
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
2.1
2.2
2.3
2.5
2.6
2.8
3
3.2
3.3
3.5
3.8
4
4.2
4.5
4.7
5
5.3
5.6
5.9
6.2
6.5
6.9
7.3
7.7
8.1
8%
1
1.1
1.2
1.3
1.4
1.4
1.5
1.6
1.8
1.9
2
2.1
2.3
2.4
2.5
2.7
2.9
3
3.2
3.4
3.6
3.8
4.1
4.3
4.6
4.8
5.1
5.4
5.7
6
6.3
6.7
7.1
7.4
7.8
8.3
6%
1.1
1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
2
2.2
2.3
2.5
2.6
2.8
2.9
3.1
3.3
3.5
3.7
3.9
4.2
4.4
4.7
4.9
5.2
5.5
5.8
6.2
6.5
6.8
7.2
7.6
8
8.5
4%
1.1
1.2
1.2
1.3
1.4
1.5
1.6
1.7
1.8
2
2.1
2.2
2.4
2.5
2.7
2.8
3
3.2
3.4
3.6
3.8
4
4.3
4.5
4.8
5
5.3
5.6
6
6.3
6.6
7
7.4
7.8
8.2
8.6
2%
1.1
1.2
1.3
1.4
1.5
1.5
1.7
1.8
1.9
2
2.1
2.3
2.4
2.6
2.7
2.9
3.1
3.3
3.5
3.7
3.9
4.1
4.4
4.6
4.9
5.2
5.5
5.8
6.1
6.4
6.8
7.2
7.6
8
8.4
8.8
0%
1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
2
2.2
2.3
2.5
2.6
2.8
3
3.1
3.3
3.5
3.7
4
4.2
4.5
4.7
5
5.3
5.6
5.9
6.2
6.6
6.9
7.3
7.7
8.1
8.6
9
