USE CASE - TOO LOW VPD (humidity too high) 

  • Plants are unable to evaporate enough  water to enable the transport of minerals (calcium) to growing plant cells, even that the stomata may be fully open. 
  • At extremly low VPD water may condens onto leaves, fruits and other plant parts. This can provide a medium for fungal growth and disease. 
  • At low VPD also gutation can occur (plant exude water from their leaf cells).
  • When plants are unable to evaporate water, excessive turgor pressure within cells can cause splitting and cracking of fruits (for example tomato)
  • In cases where VPD alternates between too high and too low, fruit quality can be adversely affected by shrink cracks in the skin of the fruit, as turgor pressure alternately expands and contracts the water-filled cells in the fruit.

Vpd Ranges Rh, Temp  Vpd Ranges