October-December, 2013 Performance of Okra under Drip Irrigation with Saline Water 72 Water resources in India at present face many challenges, including increasing demands in many sectors. Such demands may demand a good fraction of fresh water presently being used by the agriculture sector. To compensate this, attention must be paid for the use of poor quality waters in agricultural sector so as to ensure sustainability with increased production that can address food and nutritional security of the nation. India now tops in the world standing with about 1.9 Mha of area covered under micro-irrigation (ICID, 2013). Drip irrigation does not only conserve water, but also improve productivity and quality of the produce even utilizing poor quality waters. Limited numbers of study have been conducted in India to assess and ascertain its utility and suitability under different situations, particularly in saline situations for production and productivity of water, crop and fertilizers (Saxena and Gupta, 2004; Pandey et al., 2010). Therefore, the present study was conducted to study the effect of different salinity levels of irrigation water on the yield and water-use efficiency of okra (Abelmoschus esculentus L. Moench) under drip system. MATERIALS AND METHODS The study was conducted at the research farm of Central Soil Salinity Research Institute, Karnal, Haryana (29 0 9’50” - 29 0 50’ N latitude and 76 0 31’15”-77 0 12’45” E longitudes and at an average altitude of 240 m above MSL). The area receives about 560 mm of annual rainfall. The soils of the experimental area belong to Zarifa Viran series of sub-order Aquic Natrustalf, and are sandy loam to loam in texture at the surface (0-15 cm) and loam to clay loam in lower layers. The average values of soil pH s , electrical conductivity (EC e ) and exchangeable sodium percentage (ESP) of the saturation paste was determined at 8.1, 0.9 dS.m -1 and 5.4, respectively, whereas soil clay was determined at 19.6 per cent. Experiment Design and Field Layout Field experiment was laid in Randomized Block Design (RBD) with 4 treatments of saline irrigation water (EC iw - fresh water (0.2), 2.0, 4.0, 8.0 dS.m -1 ) in 3 replications. Appropriate quantities of salts were mixed per litre of water (ratio of Ca:Mg and Cl:SO 4 kept at 1:1, while sodium absorption ratio, SAR, maintained at 10) to achieve the desired salinity levels of irrigation water for different treatments (Table 1). The experimental layout was prepared as described in Fig. 1. The system had four parallel sub-mains with control valves, each for separate salinity level as described above. Spacing between the laterals was kept at 2 m. One control valve was provided on each lateral. Emitters of 8.0 l.h -1 discharge rating were placed at 0.6 m apart on each lateral (12 mm OD) of 12 m length leaving a distance of about 2.4 m from the sub-main pipe. Okra (Var: Mahyco-10 Hy) Journal of Agricultural Engineering Vol. 50 (4): October-December, 2013 SWE-11/13 Research Note Performance of Okra under Drip Irrigation with Saline Water C.K. Saxena 1 , S.K. Gupta 2 , R.C. Purohit 3 , S.R. Bhaka 3 and B.Upadhyay 4 Manuscript received: July, 2013 Revised manuscript accepted: October, 2013 ABSTRACT A study was conducted at the research farm of Central Soil Salinity Research Institute, Karnal, to evaluate the effect of salinity of irrigation water on the yield of okra (Abelmoschusesculentus L. Moench) under drip irrigation. The experiment was conducted in randomized block design with 4 levels of saline irrigation water (EC iw = 0.2, 2.0, 4.0, 8.0 dS.m -1 ) in three replications. Significant change in the yield of okra (Var: Mahyco-10 Hy) was observed at 1% level of significance. It was found that even at 8 dS.m -1 irrigation water salinity, 77% of okra yield to the check could be obtained. Highest water use efficiency was with available fresh water of 0.2 dS.m -1 at 0.49, and for the treatments of 2.0, 4.0, 8.0 dS.m -1 it was observed at 0.49, 0.46 and 0.38 t.ha -1 .cm -1 , respectively. Key words: Drip irrigation, saline water, fresh water, okra, water use efficiency 1 PhD Scholar, Department of Soil and Water Engineering, College of Technology and Engineering, MPUAT, Udaipur (Raj.) 313 001 (E-mail: cksaxena@gmail.com), 2 Scientist Emeritus, Central Soil Salinity Research Institute, Karnal 132 001; 3 Professor, Department of Soil and Water Engineering, College of Technology and Engineering, MPUAT, Udaipur, 4 Professor, Department of Agricultural Statistics, Rajasthan College of Agriculture, MPUAT, Udaipur 313001.