Development of a High-Yield and Environmentally Friendly Hydroponic System of Cucumber

Recently, hydroponics became popular in some vegetables, such as tomatoes and strawberries, but hydroponics for cucumbers has not been established. This chapter introduced the development of a high-yield and environmentally friendly hydroponic system of cucumber. In the hydroponics of cucumbers, hanging training is the most suitable branching method because of its superior yield and quality. Chip charcoal with a 3–5 mm diameter was the best-supporting medium, and the same chip charcoal could be repeatedly used for over ten successive cultivations. In an open system, concentrations of a nutrient solution indicated by electrical conductivity for cucumber were suitable from 1.5 to 2.0 dS/m. A new circulation hydroponic system has been developed, in which nutrient solution in a storage tank dripped into the culture medium, and the discharged wastewater from the medium was recycled into the storage tank. The nutrient solution did not change throughout the cultivation period, and the total amounts of nutrients in the circulating system were reduced by about 50 to 75% compared to the open system. In cucumber hydroponics, the increase in the K/Ca ratio improves the commercial fruit yield. Hydroponics of cucumbers not only significantly increased yields compared to soil cultivation but also reduced labor time.