86 1 Principal Scientist (e mail: skluthra@hotmail.com), 2 Principal Scientist (e mail: srawalcpri@gmail.com), 3 Principal Scientist (e mail: vijaigupt@gmail.com), 43 Principal Scientist (e mail: malikkamlesh7@gmail.com) Indian Journal of Agricultural Sciences 88 (7): 1070–6, July 2018/Article https://doi.org/10.56093/ijas.v88i7.81553 Performance of potato (Solanum tuberosum) advanced hybrid MS/6-1947 under high temperature stress and water defcit conditions S K LUTHRA 1 , SANJAY RAWAL 2 , V K GUPTA 3 and KAMLESH MALIK 4 ICAR-Central Potato Research Institute, Regional Station, Modipuram, Meerut, Uttar Pradesh 250 110 Received: 28 June 2017; Accepted: 17 April 2018 ABSTRACT In present investigation, potato (Solanum tuberosum L.) advanced stage hybrid MS/6-1947 was evaluated along with controls under high temperature and water stress regimes for three successive winter crop seasons. Under high temperature at Modipuram, MS/6-1947 (13.3 t/ha) showed yield enhancement of 20, 9 and 11% over the controls Kufri Bahar, Kufri Pukhraj and Kufri Surya. It also exhibited at par tolerance to hopper with Kufri Surya and damages due to mite burn were lower than Kufri Bahar and Kufri Pukhraj. The hybrid possessed 18% tuber dry matter. Results on drought toleranceat Modipuram revealed superior performance of MS/6-1947 under normal irrigation, mild water and severe water stress conditions as compared to best control Kufri Pukhraj as yield reduction was comparatively lower under mild and severe water stress treatments. Drought tolerance index (DTI) values were maximum in MS/6-1947 (1.02 and 0.79) followed by Kufri Pukhraj (0.86 and 0.51) and Kufri Bahar (0.72 and 0.58) under mild and severe water defcit treatments, respectively. Drought tolerance studies at Jodhpur revealed better performance of MS/6-1947 under normal and mild water stress conditions as compared to the controls Kufri Pukhraj and Kufri Surya as yield reduction was comparatively lower under mild water stress conditions. DTI values were maximum in MS/6-1947 (1.08) followed by Kufri Puhkraj (1.01) and Kufri Surya (0.41) under mild water defcit treatment. Tuber dry matter content increased under water stress over normal irrigation at both the locations. MS/6-1947 is suitable for table potatoes. MS/6-1947 may be a better option for integrating in cereal based crop sequences, for exploiting its yield potential in early season and for attaining sustainable productivity in areas where high temperature and lower water availability are constraint for raising the successful potato crop. Key words: Drought tolerance, High temperature stress, Night temperature, Potato, Water stress. Environmental stresses like higher atmospheric temperatures, salinity and drought affect plant growth and productivity in several crop species including potato (Solanum tuberosum L.). Negative impact of abiotic stresses (temperature and water) due to changing climate scenario is expected to increase in coming decades on potato production and its extension in non-traditional areas (Hijmanns 2003). High temperature during active crop growth phase is major limiting factor for potato production in many developing countries (Dodds 1990). Reduction in leaf area, tuber number and tuber weight has been reported as symptoms of elevated temperatures during potato growing season (Menzel 1985). Heat stress creates imbalance in source-sink relation, delay in tuber initiation and bulking and malformation and necrosis of tubers (Levy and Veilleux 2007). Optimum temperature for the growth of crop canopy is about 25°C. Minimum night temperature plays a crucial role in tuberization and largely determines whether plant will tuberize or not. Optimum temperatures for tuber formation are widely in the range of 10-17 0 C (Bodlaender 1963, Moorby and Milthorpe 1975). Normally, tuberization is reduced at higher night temperatures (> 20°C) with complete inhibition of this process above 25°C. A progressive reduction in tuberization is encountered with increasing temperature up to 30°C (Khanna 1966). Exposure of potato plants to heat stress alters the hormonal balance in the plants and results in partitioning of most of assimilated carbon in favour of above ground vegetative parts at the cost of the tubers. In India, high temperature during crop growth and tuberization restricts adoption of potatoes in early planting conditions of north- western plains and peninsular India (Luthra et al. 2006; Luthra et al. 2013). Early planted crop is vulnerable to attack of sucking pests like leafhopper (Amrasca biguttula Ishida) and mite (Polyphagotorsonemus latus Banks) resulting in signifcant yield reduction (Malik and Luthra 2007, Luthra et al. 2013). It is imperative to develop potato clones which could germinate, grow and tuberize well under high night temperatures to mitigate the likely effect of climate change