CHARACTERISTICS OF ORGANIC GROWING MEDIA FOR HYDROPONIC CULTIVATION PREPARED FROM LEAVES AND STALKS OF EGGPLANT WITH CRUDELY CRUSHED AND SOAKED IN WATER

Preparation of alternative soilless organic media with a simple method was investigated to utilize tons of crop residues in a closed loop in agricultural areas. Leaves and stalks of eggplant were used in this study, and the leaves and stalks crudely crushed up to a maximum of 3 cm were soaked into water to reduce electronic conductivity (EC) in the biomass. Water extracts showed their germination and following growth inhibition in a germination inhibition test using grape tomato seeds. Also, heat treatment (e.g., 70oC in a dry oven) reduced the inhibition effect. Then, prepared growing media of eggplant’s leaves and stalks crudely crushed and soaked into water was applied to cultivate grape tomato (cultivation period 53 days; n = 3). Mineral wool, commonly used growing media, was used as a control. Although the average growth of grape tomato in the prepared organic media was lower than that in the mineral wool, one grape tomato was able to grow as much as that in the control case under controlled circumstances. This might indicate that the prepared growing media have the potential to grow plants. Through investigation of characteristics of the prepared growing media, challenges were set to address its high pH, high EC, and low water-holding capacity.