LAUSR

Abstract Chemical controls in hydroponic cultures are common in developing countries. However, safe agricultural production and the reduction of chemical controls play important roles in human health and the environment. As a clean and sustainable source of energy, solar water disinfection can realize this goal in hydroponic cultures especially in hot countries with high solar radiation. Various solar collectors have been developed for removing plant-root pathogens from water, however, the contribution of solar energy in the reduction of chemical controls has remained unknown. This research is thus aimed to investigate the potential of the sun in water disinfection and the theoretical feasibility of chemical control reduction. The typical amount of water needed to be daily disinfected in a hydroponic culture ranges from 400 to 1000 L for a 1000-square meter greenhouse. A flat plate collector (FPC) and an evacuated tube collector (ETC) were employed as conventional solar collectors to convert solar energy to heat. TRNSYS software was used to obtain the useful energy gain of the collectors. The results showed that solar energy could eliminate fungicide consumption at acceptable costs.