Articles
Microclimate and cucumber crop transpiration in a greenhouse cooled by pad and fan system
Article number
1271_33
Pages
235 – 240
Language
English
Abstract
The microclimate and cucumber soilless crop response in an evaporatively cooled greenhouse were studied in Cyprus during spring.
Measurements were carried out in two greenhouse compartments: (1) a compartment in which a wet pad and fan system for evaporative cooling of the greenhouse environment was operated, and (2) a compartment in which greenhouse cooling was performed by means of forced ventilation with outside air.
Compared to forced ventilation, evaporative cooling was able to reduce mean air temperature by about 7.5°C and maintained greenhouse air temperature below 28°C, while mean air temperature without cooling reached values higher than 34°C, closed to the external air temperature values.
Furthermore, evaporative cooling reduced air vapor pressure deficit by about 60% and maintained mean greenhouse air vapor pressure deficit below 1.6 kPa.
In addition, evaporative cooling resulted in an about 4°C lower leaf temperature values compared to the case of forced ventilation.
The cucumber crop transpiration rate was about 20% higher in the compartment cooled by forced ventilation than in the one with evaporative cooling.
Finally, it was estimated that the crop stomatal conductance was about 25% higher for the crop cooled by the evaporative cooling system than the crop cooled by forced ventilation.
Measurements were carried out in two greenhouse compartments: (1) a compartment in which a wet pad and fan system for evaporative cooling of the greenhouse environment was operated, and (2) a compartment in which greenhouse cooling was performed by means of forced ventilation with outside air.
Compared to forced ventilation, evaporative cooling was able to reduce mean air temperature by about 7.5°C and maintained greenhouse air temperature below 28°C, while mean air temperature without cooling reached values higher than 34°C, closed to the external air temperature values.
Furthermore, evaporative cooling reduced air vapor pressure deficit by about 60% and maintained mean greenhouse air vapor pressure deficit below 1.6 kPa.
In addition, evaporative cooling resulted in an about 4°C lower leaf temperature values compared to the case of forced ventilation.
The cucumber crop transpiration rate was about 20% higher in the compartment cooled by forced ventilation than in the one with evaporative cooling.
Finally, it was estimated that the crop stomatal conductance was about 25% higher for the crop cooled by the evaporative cooling system than the crop cooled by forced ventilation.
Authors
N. Katsoulas, G. Nikolaou, D. Neocleous, C. Kittas
Keywords
evaporative cooling, transpiration, water use efficiency, stomatal conductance
Groups involved
- Division Greenhouse and Indoor Production Horticulture
- Division Precision Horticulture and Engineering
- Division Plant-Environment Interactions in Field Systems
- Working Group Nettings in Horticulture (subgroup of Protected Cultivation in Mild Winter Climates)
- Working Group Light in Horticulture
- Working Group Organic Greenhouse Horticulture
- Working Group Modelling Plant Growth, Environmental Control, Greenhouse Environment
- Working Group Protected Cultivation, Nettings and Screens for Mild Climates
- Working Group Vegetable Grafting
- Working Group Computational Fluid Dynamics in Agriculture
- Working Group Design and Automation in Integrated Indoor Production Systems
- Working Group Mechanization, Digitization, Sensing and Robotics
- Working Group Greenhouse Environment and Climate Control
- Commission Agroecology and Organic Farming Systems
Online Articles (65)