RANGA REDDI, M.SHANTI, K.2018-05-292018-05-291994D4537http://krishikosh.egranth.ac.in/handle/1/5810047996A field experiment with five levels of nitrogen(O, 40, 80, 120 and 160 kg ha ) as main treatments and two varieties viz., DEM—107 and Varun as sub—treatments each replicating four times in a split-plot design was conducted during kharif 1993—94 on sandy loam soils of College farm, College of Agriculture, Rajendranagar, Hyderabad. The objective was to compare the relative performance of hybrid and composite and to find out optimum dose of nitrogen. All the growth parameters, yield attributesexcept number of cobs plant , grain yield, nutrient uptake and protein content in grain increased signifii cantly with each higher level of nitrogen upto 120 kg ha Application of 160 kg N ha_ did not prove to be advantageous over 120 kg N ha . However 5 over yield was increased significantly upto 160 kg N ha_ . Further the results indicated that hybrid DEM—107recorded significantly higher growth parameters (except plant height) yield attributes, grain and stover yields and nutrient uptake over Varun. The interaction between varieties and nitrogenlevels were found to be significant only in case of dry matter accumulation at 60 DAS and in yield attributes viz., number of grains cobl an 100 grain weight° A maximum grain yield of 42.4 3 ha was obtained with the application of 120_lkg N ha . Whereas hybrid DHM-107 recorded 34.52 q ha in comparison_fo composite variety Varun which recorded only 27.78 q ha . The regression of grain yield on nitrogen levels in hybrid DHM—107 and composite Varun indicated that the response was cubic in nature.ennullThesis