Physiological and biochemical changes in quinoa Chenopodium quinoa Willd under moisture deficit stress and climate resilient approaches for enhancing productivity and quality A Thesis submitted to the Odisha University

Abstract

A field study was conducted at Instructional farm, Odisha University of Agriculture newlineand Technology, Bhubaneswar during Rabi 2021-22 and 2022-23 to quantify the effect of newlinemoisture deficit stress at different critical growth stages of quinoa (Chenopodium quinoa newlineWilld.) and different mitigation approaches were adopted in order to alleviate the effect of newlinemoisture deficit stress. The experiment was designed in split plot design comprising of six newlinemain plots (moisture deficit stress) and four sub plots (stress mitigation approaches). The soil newlineof experimental site was sandy loam, slightly acidic in reaction (pH 5.82), low in organic newlinecarbon (0.49%) and available nitrogen (248.4 kg/ha), medium in available phosphorus newline(41.2 kg/ha) and available potassium (263 kg/ha). The treatments in main plots viz., no newlineirrigation at branching (M1), at panicle formation (M2), flowering (M3), grain filling stage newline(M4), irrigating at all four stages (M5) and irrigating as and when required at IW/CPE 0.8 newline(M6), and sub plot treatments viz., soil test-based fertilizer recommendation (STBFR at newline60:30:30) (S1), STBFR+Salicylic acid spray at 100 ppm (S2), STBFR + rice straw mulching newlineat 5 t/ha (S3) and integrated nutrient management (75% N Inorganic + 25% N FYM) (S4), newlinewere tested. Moisture stress was imposed by withdrawing irrigation at defined stages. The newlinepooled analysis revealed that the least grain yield and harvest index were recorded when newlinemoisture deficit stress was induced at branching stage (592 kg/ha and 0.22, respectively) newlinewhich was followed by no irrigation at panicle formation stage (651 kg/ha, 0.24, respectively) newlineand the highest yield and HI were obtained by irrigating the crop as and when required newline(1989 kg/ha, 0.33, respectively). Moisture deficit stress imposed at different phenophases newlinereduced the different physiological traits viz., relative water content (13.3-29.4%), total newlinechlorophyll content (14.5-27.0%), NVDI (21.6-44.2%), SPAD value (14.0-27.1%), newlinechlorophyll stability index (3.7-19.2%), membrane stability index (14.5-29.4%) with newlinema