S06 - Session O1 - Evaluation of environmental parameters of a phytotron for Cannabis cultivation.

Authors: Paula Andrea Uribe Benavides *, Juan Manuel Galindo

A plant growth, control or phytotron room is a space in which plant growth material is sought by simulating different environmental conditions, by means of equipment in charge of modifying and controlling different variables such as temperature, relative humidity, luminosity, irrigation, among others. For this work, a 6.5 m 2 closed room was used in the Agricultural Engineering laboratory at the National University of Colombia. A mobile platform with a pulley system was built to adjust the height of the LED lighting, the hydraulic network for irrigation and humidifiers was installed. In addition, an electrical network was installed for all the controlled equipment (heating, LED lights, extraction, and ventilation) by an HMI placed in the entrance door where the variables temperature and relative humidity are monitored and controlled. The equipment was evaluated in day/night cycles with plants and without plants indoors. For the tests there was always continuous air exchange and the heating on during daylight hours and nebulizers off. In the test without plants, a maximum temperature of 35°C was achieved. It is believed that, when the temperature rises above 30°C, the relative humidity drops to percentages below 30%. Regarding the tests carried out with 20 plants in a pre-flowering state indoors, a different hygrothermal behavior was found. A maximum temperature of 30.9 ° C was achieved under day conditions. It is observed that the increase in temperature is linear and the relative humidity increases more rapidly in the beginning and the relative humidity rises to levels almost 60% and falls approximately 10% before reaching the maximum temperature.This demonstrates the important effect of the evapotranspiration of plants in the microclimate and the importance of taking it into account in the design of indoor growing equipment.