The yield of the crops may be subject to the distribution of water directly to the plant root zone using drippers or emitters. To date, there has not been adequate work to evaluate irrigation system performance and water productivity (WP) specifically for rock melon inside a netted rain house shelter in tropical area. Amongst the problem of this system is the non-functional irrigation components after been used for specific of time, thus reducing the irrigation efficiencies and distribution uniformity. This study evaluates irrigation performance of drip irrigation system and estimates WP of rock melon cultivation in the netted rain house shelter. The results indicate that the operating pressure of the drip irrigation system tested varied from 0.8 to 3.0 psi with a discharge rate between 0.14 and 0.25 Lmin-1. Water application uniformity between laterals varied from 66.06 to 89.72%. The WP of rock melon was around 7.93 kg/m3, which is considerably high and in similar range as demonstrated in previous literature. The field evaluation also reveals that the manipulation of valve controller at lateral based on a few selected scenarios did not provide a significant difference in pressure and discharge at the head, middle, and tail section of the drip irrigation system. Such findings would be a very useful information for a precision water management particularly for rock melon cultivation grown under rain house shelter system.
