Journal of Soil and Plant Interactions

In this research, the ability of a fuzzy logic control (FLC) system in providing optimal temperature and humidity inside greenhouse and the effect of FLC on the growth parameters of basil plant were aimed. At first, the FLC algorithm was implemented in Fuzzy Tech software. Second, two small, separated and isolated spaces were prepared as model and control greenhouses. Then, the FLC equipment were installed inside model greenhouse, including temperature, humidity and soil moisture sensors along with a fan, a heater, a fogger system and electric valves as actuators. During 40 days experiments, temperature and humidity changes inside and outside of the greenhouse were recorded. Finally, the basil plants were harvested and some growth parameters of the crop were measured. The results showed that the FLC greenhouse was more capable than the control greenhouse in providing the plant's growth conditions. The root mean square errors (RMSE) of temperature were 1.33 and 5.71 ^oC, and of humidity were 2.29 and 19.45% in FLC and control greenhouses, respectively, which indicates better performance of FLC than On/Off control for providing optimum temperature and humidity for plant’s growth. Both greenhouses had the same performance at germination percentage, but the FLC greenhouse had better performance at other growth parameters. The measured values for dry and fresh weights of basil plant in the FLC greenhouse showed 50 and 35% increase in the yield, respectively, compared to the control greenhouse. In general, the results of this study showed that the fuzzy control method is able to optimally control the environmental conditions of greenhouses; so it is recommended for use in new greenhouses.