INT. J. BIOL. BIOTECH., 12 (3): 485-491, 2015. IMPACT OF SALINITY ON GROWTH, YIELD AND WATER USE EFFICIENCY OF MOMORDICA CHARANTIA L. UNDER RAISEDBED IRRIGATION Ashifa Soomro 1 , Kamran Baksh Soomro 2 , Javed Akhtar 2 , Salahudin Soomro 3 and Ahmed Ali Tagar 4 1 Department of LWM, FAE, SAU, Tandojam, Pakistan 2 CDRI, SARC, PARC, Karachi, Pakistan 3 Department of Land and Water Management, Faculty of Agricultural Engineering, Sindh Agriculture University, Tandojam 4 Department of Farm Power and Machinery, Sindh Agriculture University, Tandojam ABSTRACT The study was conducted at the experimental field of Faculty of Agricultural Engineering, Sindh Agriculture University Tandojam during the year 2013, with the hypothesis that saline water can successfully be used for growing bitter gourd ( Momordica charantia L) in soil and climatic conditions of Sindh. In this study, the saline water was used with raised bed furrow irrigation method and the soil texture was silt loam. The randomized complete block design (RCBD) with four treatments (I1, I2, I3 and I4) and three replications was laid in the study. I1 was fresh water, I2, I3 and I4 water were with ECw 3dS/m, ECw 4dS/m and ECw 5dS/m respectively. The seeds were sown on both sides of ridge at a depth of 2-3 cm. Plant to plant distance of 40-45 cm was maintained. Irrigation media was prepared by mixing NaCl for required ECw in drums then applied to the experimental plots. The interval among each irrigation was kept 7 days. The experiment results revealed that, the average soil ECe increased 0.09, 0.57, 0.96 and 1.47dS/m in I1, I2, I3 and I4 respectively. pH decreased as 0.2 with I1, I2, I3 treatments and 0.3 with I4 treatment. The infiltration rate (cm/h) and porosity (%) were increased, thus the dry density (g/cm 3 ) of soil profile decreased. The average yield of bitter gourd was obtained 11.47, 9.65, 7.92and 6.76 kg with treatments I1, I2, I3 and I4, respectively, thus the yield of crop was decreased as 15.84%, 30.95% and 41.07% with treatments I2, I3 and I4 (saline water) when compared to treatments with freshwater (I1) irrigation. Agronomical data were observed decreasing with the increasing ECw of the irrigation water. The crop water productivity (CWP) for treatments I1, I2, I3 and I4 was found 3.07, 2.58, 2.12 and 1.81 kg/m 3 , crop water productivity decreased with use of saline water. The present study suggests that farmers can use saline water having ECw ≤ 5dS/m for the bitter gourd at reduction of 41% (approximately) of the production. Key-words: Salinity, water efficiency, yield, bitter gourd. INTRODUCTION The scarcity of good quality irrigation water is a serious problem in arid and semi-arid areas of the world which include one third of the earth. Freshwater resources are very scarce, just 3% of the total earth supplies water from which 1% freshwater and 2% ice water reserves for agricultural purpose and left behind 97% water in Sea is extremely saline and not suitable for large amount utilization in agriculture. More than half of the world’s groundwater supply have also turned saline (FAO, 2003). The surface and groundwater quality is deteriorating day by day. The indiscriminate discharge of industrial and domestic waste water into open water bodies and groundwater is the main threat to the Pakistan water reserves (Kahlown and Majeed, 2002). In arid and semi-arid regions, commercial agriculture is mainly dependent on the easily available good quality irrigation water. Fresh surface water supplies in these areas are slowly becoming short to meet the crop water requirement. Soil salinity is one of the large spread environmental stresses that impose serious threat to the germination, plant growth and yield. Crop yields start declining when pH of the soil solution exceeds 8.5 or EC cost goes higher than 4 dS/m. At higher EC values the crop yield are reduced so significantly that crop cultivations is not economical without soil amendments. Addition of salt to water, lower its osmotic potential, resulting in decreased availability of water to root cells (Sairan, 2002). The cultivation of crops with increased salt tolerance and the adoption of new crop and water management strategies enhance and facilitate the use of saline waters for irrigation and crop production, while maintain soil salinity from becoming excessive (Rhoades et al., 1992). There is a critical need to develop methods to use low quality water and degraded land to boost the agricultural productivity (Bilquees and Khan, 2003). Agriculture production with saline irrigation water has been extended significantly in the last decade. It is usually accepted about 10% irrigated area are affected by salinity (Dinar, 2009). Raised bed planting system is used since time immemorial by farmers in various parts of the world (Govaerts et al., 2007). About 90% of irrigated lands around the world are irrigated by furrow irrigation method and furrow irrigation needs less energy (Tiercelin and Vidal, 2006). Furrow irrigation method conserves water, as it applies