Field experiment was conducted during 2015-16 and 2016-17 at ICAR-Sugarcane Breeding Institute, Coimbatore, India to study the response of six elite sugarcane varieties viz., Co 09004, Co 08009, Co 08016, Co 08020, Co 86032 and CoC 671 to higher nitrogen levels. The experiments were laid out in split plot design with three replications. The soil of the experimental site was clay loam in texture, taxonomically classified as typic haplustalf, low in organic carbon and available N and high in available P and K, neutral in reaction with normal electrical conductivity. The prevailing climatic condition during experimentations represented tropical wet and dry climate, with the wet season lasting from October to December due to the northeast monsoon, wherein mean temperature ranged between 21.6 and 33.10C with a mean relative humidity of 56 to 85 per cent. As against the normal rainfall of 674.2 mm only 678.9 and 386.5 mm of rainfall were received during 2015-16 and 2016-17 crop seasons indicating the erratic behavior of rainfall. The results clearly indicated that mid-late maturing varieties Co 08009 (157.18t/ha) and Co 86032 (152.94 t/ha) equally performed well and significantly out-yielded the other mid-late sugarcane varieties Co 08016 and Co 08020. The early maturing Co 09004 (152.11 t/ha) was superior compared to the check variety check variety CoC 671 (129.12t/ha) and found to be more promising with the cane yield of improvement of 17.80 per cent. A significant progressive increase in cane yield was observed with the increase in the dose of nitrogen from 75 to 150 % RDN. Application of 125 % RDN (281kg N/ha) resulted in significantly high cane yield of 154.55 t/ha but it was at par with 100 and 150 % RDN. The results of the experiment revealed that the effect of application of graded level of nitrogen on mean cane yield was significant wherein application of 100, 125 and 150 % of recommended dose of nitrogen recorded significantly higher cane yield over 75 % RDN. The effect of nitrogen application on juice quality was non-significant. A significant differential genotypic response to nitrogen levels was observed wherein Co 86032 the mid-late check variety exceptionally responded linearly up-to 150 of RDN whereas Co 08009, Co 08020 and Co 08016 gave better response up to 125 % RDN and 100 % RDN, respectively. Both the early maturing sugarcane varieties Co 09004 and CoC 671 responded up to 125 % of applied RDN. Thus the newly released early maturing variety Co 09004 with better juice qualities was found significantly superior in terms of cane height (249.23 cm), NMC/ha (98.94 x 103), cane yield (152.11 t/ha) and CCS yield (21.95 t/ha) over check variety CoC 671. Based on the results of the investigation it is concluded that for realizing maximum cane yield of newly released Co 09004 variety, application of 281 kg of nitrogen (125 % RDN) is recommended under tropical Indian condition in clay loam soil.

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