Energy consumption, light distribution and plant growth in greenhouse partly insulated with non-transparent material

Summary Energy consumption for heating a separate greenhouse insulated with opaque insulating material with high reflection was reduced by 28% compared to an uninsulated single glass greenhouse. To improve light distribution across the insulated greenhouse and to obtain the same light sum in both greenhouses an algorithm for controlling the artificial light was used. The electricity consumption of the artificial light was increased by 38% in the insulated greenhouse leading to an overall reduction by 25% in energy consumption because production time was equal in both greenhouses. Dendranthema grandiflora was grown at two densities of 36 and 45 plants m-2 under short day condition. In the insulated greenhouse the plant growth was influenced by plant density and high density increase the plant height. In the uninsulated greenhouse there was a spatial variation in plant height depending of plant density and position in the greenhouse. The spatial variation in growth of Dendranthema grandiflora was lesser in the insulated greenhouse owing to the equalization of light conditions and higher canopy temperature in the insulated part of the greenhouse.