Influence of Drip-irrigation Method on Performance and Yields of Cucumber and Tomato

The conservation of water is crucial to sustainable agricultural production in areas of low rainfall or uneven precipitation distribution. Under such circumstances, drip irrigation methods offer a useful option for economic production of vegetable crops. This preliminary study examined the efficacy and performance of two drip irrigation methods on cucumber and tomato crops grown out of season. The initial results of the study indicated surface drip irrigation to give better establishment of the crop and higher yields than sub-surface drip method. Further work is needed, however, to establish the cause-effect relationships and actual viability of sub-surface drip irrigation method. INTRODUCTION An important constraint to agricultural production is the availability of water for crop growth. Water is often a major limiting factor in regions of low rainfall (semi-arid and arid regions) or in agro-climatic zones where rainfall is unevenly distributed throughout the year. Such is the case over much of Nepal, which has a distinct rainy season (monsoon) followed by a prolonged dry season (UNEP 2001). Moreover, the production of out-of-season vegetables like cucumber, tomato, capsicum and cauliflower requires supplemental water. In many parts of the country, an abundant supply of water is not available during the dry period (typically from November to May or June), hence water conservation and minimizing its use for irrigating crops is crucial for sustainable economic production of vegetable and other cashcrops (Randhawa and Abrol 1990). To this effect, drip irrigation offers a feasible option for economic production in areas of low rainfall or periods of water scarcity. Drip irrigation refers to any system of watering cultivated crops in which the water is delivered directly to each individual plant on a gradual and continuous basis (Swhwab et al., 1993). The purpose of this preliminary study was to evaluate the efficacy of two different methods of drip irrigation, namely surface and sub-surface drip, on the performance and yields of cucumber and tomato in the central Nepal mid-hills. MATERIAL AND METHOD In order to test the response of vegetable crops to method of water delivery by drip-irrigation, a field plot experiment using a randomized complete block design was established within the Kathmandu University campus, Dhulikhel, Kavre. The experiment had two crops (cucumber and tomato) in separate blocks, two drip delivery techniques (surface and sub-surface) and four replications of each treatment (see figure 1 for details of plot layout). The main treatment was to test the effect of water delivery technique, i.e., via surface or sub-surface drip, on water use efficiency as reflected by the growth and yield of vegetable crops.