Atul KumarSingh, Nancy2021-03-132021-03-132021-01https://krishikosh.egranth.ac.in/handle/1/5810162377Rice is the staple food for more than three billion people in the world. With increasing global population, the demand for rice has been steadily increasing. Rice yield has been significantly increased over the recent decades. However, due to various reasons like low profitability of crop production, limited access to new agricultural technologies and climate change, “the objective of increasing rice yield per unit area with less harmful impact to the environment has become a major global concern.” In rice cultivation, fertilizers represent about 19% of production costs; however, proper fertilization management helps increase performance and could reduce production costs and increase crop yields. Silicon is attributed with many beneficial effects for the cultivation of rice, as it increases the tolerance to abiotic and biotic stress. This nutrient reinforces the cell wall and, thereby, increases the biomass and grain production. A field experiment was performed in split-plot design replicated thrice with four treatments viz., T1: Control, T2: Si fertilized T3: Si + water stress and T4: water stress. Stress was imposed by withholding irrigation 12 days prior to flowering and again 10 days after anthesis. The experiment was conducted during the kharif season of 2019 to evaluate the influence of foliar applied Si on biotic and abiotic stress tolerance in different rice genotypes. Various morphological, yield attributes and biochemical parameters in nine genotypes namely IIRRH-122, IIRRH-131, IIRRH-132, HRI-174, KRH-4, JKRH-3333, US-314, 27P63 and Sahabhagidhan were observed. Silicon displayed positive influence on the growth and development and yield under both well watered as well as water-deficit conditions. Growth parameters such as plant height, tiller number, leaf number, LAI and biomass accumulation as well as yield and yield attributes such as panicle number, spikelet number, grain number, test weight and harvest index were found to enhance. The biological yield was recorded to be increased by 16% and grain yield increased by 26% under stress. Chlorophyll by 31%, protein by 17% and carbohydrate content by 49% were enhanced on application of silicon under stress. The insect and pest infestation decreased under silicon application. A decrease of 49% was recorded in stem borer and leaf infestations while blast disease decreased by 33% and blight by 41% under stress. Genotypes IIRRH-132, KRH-4 and US-314 showed great response to silicon fertilization under well-watered as well as water deficit conditions.EnglishThesis