~ 586 ~ International Journal of Chemical Studies 2019; 7(6): 586-591 P-ISSN: 2349–8528 E-ISSN: 2321–4902 IJCS 2019; 7(6): 586-591 © 2019 IJCS Received: 04-09-2019 Accepted: 06-10-2019 Nagesha BV Department of Crop Physiology, College of Agriculture, Rajendranagar, PJTSAU, Hyderabad, Telangana, India Ramesh Thatikunta College of Agriculture, Warangal, PJTSAU, Hyderabad, Telangana, India S Narender Reddy Department of Crop Physiology, College of Agriculture, Rajendranagar, PJTSAU, Hyderabad, Telangana, India L Krishna Agricultural Research Institute, Rajendranagar, PJTSAU, Hyderabad, Telangana, India K Supriya Department of Statistics and Mathematics, College of Agriculture, Rajendranagar, PJTSAU, Hyderabad, Telangana, India Corresponding Author: Nagesha BV Department of Crop Physiology, College of Agriculture, Rajendranagar, PJTSAU, Hyderabad, Telangana, India Study on morpho-physiological, yield attributes and quality parameters of rice varieties under different nitrogen levels and zinc application Nagesha BV, Ramesh Thatikunta, S Narender Reddy, L Krishna and K Supriya Abstract A field experiment was conducted during kharif, 2018 at College of Agriculture, Rajendranagar, Hyderabad to study the effect of different nitrogen levels and zinc application on growth and development in paddy. The experiment was laid out in split plot design with three varieties as main plots, six nutrient levels as sub plots and replicated thrice. Among the varieties Tella Hamsa had taken less number of days to panicle initiation (63), flowering (82) and maturity (117), recorded highest sterility % (22.7), minimum LAI (4.19, 4.50 and 2.56 at vegetative, flowering and grain filling stage respectively) and lower photosynthetic rate (17.5, 20.9 and 13 μmol CO2 m -2 s -1 at vegetative, flowering and grain filling stage respectively). Telangana Sona had taken more number of days to panicle initiation (66), flowering (86) and maturity (121), higher filled grain %, maximum LAI, maximum photosynthetic rate, more panicles m -2 , grains panicle -1 , filled grain % and low sterility %, higher grain yield and high harvest index (46). Application of 25 % higher than RDN + 0.5 % ZnSO4 foliar spray resulted in maximum LAI, maximum photosynthetic rate, panicles m -2 , grains panicle -1 , filled grain % Panicle length, grain yield, more test weight and harvest index. Quality parameters were significantly influenced by the different varieties and nitrogen levels. Between varieties, Telangana Sona recorded significantly higher hulling (84.3), milling (73.7) and head rice recovery percentage (65.1). Keywords: Photosynthetic rate, leaf area index, harvest index, test weight Introduction Rice is a staple and an important food crop around the whole world serving the food requirements of more than half of the world population. In India, rice is grown in an area of 44.5 M ha with a production 115.60 Mt and a productivity of 2800 kg ha -1 .Telangana State contributes 2.09 m ha area annually with a production of 6.62 mt, with an average productivity of 3295 kg ha -1 during 2018-2019 (CMIE, 2019) [2] . Nitrogen is one of the most important nutritional elements contributing for higher productivity of cereal crops and a major factor that limits agricultural yields (Balasubramanian et al., 2000) [1] . To obtain a better crop yield, one of the major criteria which need to be taken care of is the plant nutrition. Nitrogen on the basis of its function has been categorized as an essential element, which most recurrently limits the crop yield and growth (Fageria et al., 2005) [3] . Nitrogen is the indispensable nutrient for rice production and its uptake is affected by rice varieties, fertilizer levels, nitrate, ammonium transporters, soil and environmental conditions etc. Nitrogen absorbed by rice during the vegetative growth stages contributes in growth during reproduction and grain filling through translocation. The application of nitrogen fertilizer either in excess or less than optimum rate affects both yield and quality of rice to remarkable extent, hence proper management of crop nutrition is of immense importance (Manzoor et al., 2006) [13] . Managing nitrogen fertilization is a challenging task for farmers in rice fields because of various losses due to de-nitrification, volatilization, leaching in flooded soils resulting in low uptake and nitrogen use efficiency (Peng et al., 2006) [14] . Excess application leads to lodging, pest and disease incidence whereas low application results in low growth and yield production. Fertilizers play an important role in maximizing returns and also reduce environmental loss, thus it is important to develop fertilizer responsive varieties. Excess application of nitrogen results in prolonged vegetative growth period, days to heading, plant height and showed variable trend of increment tillers per plant with the application of higher doses of nitrogen.