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The study details the water management of hydroponically grown honeydew melon in tropical greenhouse using automatic controller. Nutrient solution was applied at two flow rates and three levels of application intervals to melon grown in three locally-available media to assess the growth and yield response. Water productivity and economic feasibility of the system were also evaluated. Results revealed that rice hull and pumice comparably produced larger, heavier and sweeter fruits than fresh coco peat. The flow rates of 1 L/hr and 3 L/hr showed comparable performances. However, nutrient solution when applied 24 times for 15 minutes performed relatively well and significantly affected the growth and yield of the melon than when applied 6 times for 30 minutes and 3 times for 30 minutes. Water productivity was higher in melons planted in rice hull with flow rate of 1 L/hr and application interval of 3 times for 30 minutes. Break-even point was equal to 1,014.43 kg/yr or only about 24 percent of the potential yearly harvest. It was concluded that in hydroponic melon production, automatic controller can simplified water management while supplying uniform and regular nutrient solution.

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Associate professor, Institute for Climate Change and Environmental Management, Central Luzon State University, Philippines; BS (1982), MS (1996) and PhD (2008) in Agricultural Engineering; postdoctoral fellow, the University of Arizona, USA (2012) under Fulbright scholarship with research aquaponic tilapia-prawn-vegetables polyculture

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