Microclimate and Efficiency Analysis of an Olive Rooting Cuttings Tunnel Greenhouse Type under Mediterranean Wintertime Climatic Conditions

Abstract

Introduction: The rooting of cuttings is a fundamental step in olive tree production. This preliminary step is favoured by specific environmental conditions, which demand strict and permanent control across the production system. Achieving these conditions poses a major challenge for propagators. In this context, the greenhouse production technique is the best response and most productive method used globally, including in the Mediterranean regions. This study aims to characterize the microclimate of a tunnel-type greenhouse according to Mediterranean wintertime climatic conditions in Morocco’s central region and assess its performance in fostering olive cutting growth. Methods: Evaluation of the efficiency of greenhouse microclimate is based on measured climatic parameters inside and outside the studied greenhouse. Also, we used a statistical data processing SPSS software for the identification regression analysis of the factors and key parameters determining the success of rooting of cuttings. Results: The experimentally obtained results clearly show for the first time that solar radiation is a determining factor for the success of rooting. The studied greenhouse type guarantees a homogeneous microclimate inside the greenhouse and allows a reduction of 66% of the external global solar radiation, which decreases transpiration and prevents leaf wilting. The results also show that the studied greenhouse system ensures an internal greenhouse air relative humidity close to saturation value and generally stable throughout the day, with a favourable value for successful rooting. However, the greenhouse air temperature was too high during the daytime and very low during the nighttime, indicating unfavorable rooting conditions. Conclusion: The results of this study can provide guidelines for propagators to improve greenhouse design and climate control to increase the yield and quality of this crop.