Evapotranspiration
Evapotranspiration is the combined loss of water through evaporation from surfaces and transpiration from plants. Temperature, sunlight, humidity, wind, and canopy size influence it. For mango irrigation, an estimate can help explain why water demand changes between cool, cloudy periods and hot, windy weather. It is not the same as a fixed watering interval or a direct measurement of one tree's need. Combine weather information with actual root-zone moisture and the tree's developmental stage.