Optimization of root spraying time for fresh onion cultivation in aeroponics

Green leafy vegetables are successfully grown in the earoponic systems. The faster harvest cycles, predictable results, higher productive yield, better crop color, texture, nutrition and flavor are the advantages of the earoponic growing. We have studied optimization of nutrient spray time on roots of fresh onion. Plants were grown in glasshouse during winter and we have built own aeroponic system. Two consecutive experiments were set up. In both experiments, the spray interval 10 minutes was constant. In the first experiment, spray times of 7,15, 21 seconds were examined and 15 sec was found to be better than the others. In the second experiment, the15 sec was considered and new spray times 10, 18 and 21 seconds were investigated. In both experiments, the plant height, white stem lenght, stem diameter, shoot and root fresh and dry weights, total soluble content, macro and micro elements, phenol and flavonoids, pH and EC and total yield were investigated. As a result, the highest biomass yield including root and the highest edible fresh onion yield were obtained from 18 sec spray time with 10 minute spray internal.