Growth performance of ICCRI 06 H cocoa seedling in response to different microclimate and soil moisture conditions

Climate and environmental factors play an important role for cocoa (Theobroma cacao L.) optimal growth and production. This study aims to evaluate growth performance and stomatal characteristics of cocoa seedling in response to microclimate, i.e. temperature, relative humidity, light intensity and soil moisture condition. The cacao variety of ICCRI 06 H was used for greenhouse experiment arranged by a completely randomized design with three replications. The first factor was evapotranspiration (ETa) i.e. ETa-1 100% (control), ETa-2 50% (moderate stress), and ETa-3 25% (severe stress). The second factor was microclimate condition defined by its location in the greenhouse, i.e. inside the glass box (IB) and outside the glass box (OB). IB microclimate conditions were modified through the installation of 50-Watt LED artificial lamps. Our seven weeks observations demonstrated the specific microclimate condition created both in IB and OB. An insignificant effect of different soil moisture level to cocoa seedling growth was evidenced. Conversely, microclimate condition shows a significant effects especially the plant height and stem diameter. The multiple regression analysis suggests the presence of connection between microclimate and crop growth, i.e. plant height, stem diameter, and number of young cocoa leaves in IB. The stomatal characteristics indicate the more stressed condition created outside the box.