Int.J.Curr.Microbiol.App.Sci (2018) 7(8): 4118-4124 4118 Original Research Article https://doi.org/10.20546/ijcmas.2018.708.428 Productivity Efficiency and Leaf Reddening in Bt Cotton (Gossypium hirsutum L.) as Influenced by SSNM Based Nutrition for Targeted Yields Vinayak Hosamani 1* , B.M. Chittapur 2 , Mallikarjun 3 , A.S. Halepyati 4 , Satyanarayana Rao 5 , M.B. Patil 6 , N.L. Rajesh 7 and Venkatesh Hosamani 8 1 P2 BSF, Nagenahally, Kunigal, Central Silk Board, Bangalore/ UAS, Raichur, Karnataka, India 2 Directorate of extension, University of Agricultural Sciences, Raichur, Karnataka, India 3 e-SAP, Project, University of Agricultural Sciences, Raichur, Karnataka, India 4 University of Agricultural Sciences, Raichur, Karnataka, India 5 PI & Head, Research Institute on Organic Farming, MARS, UAS, Raichur, Karnataka, India 6 AEEC, Koppal, UAS, Raichur, Karnataka, India 7 (SS&AC), COA, UAS, Raichur, Karnataka, India 8 Entomology, COH, Munirabad-Koppal, Karnataka, India *Corresponding author ABSTRACT Introduction Green Revolution and succeeding many other technology led revolutions in agriculture from later part of 20 th century helped to enhance productivity to cope up with the burgeoning population and industrial demands in the country. However, the repercussions of International Journal of Current Microbiology and Applied Sciences ISSN: 2319-7706 Volume 7 Number 08 (2018) Journal homepage: http://www.ijcmas.com The field experiment on cotton productivity and leaf reddening as influenced by nutrition management for targeted yield was conducted during growing seasons of 2014-15 and 2015-16 at College of Agriculture Farm, Raichur, Karnataka on medium deep black soil under irrigation. Three yield targets (3, 4 and 5 t kapas yield ha -1 ) based site specific nutrient management (SSNM) along with four leaf reddening management (LRM) treatments (S1 - Vermicompost @ 2.5 t ha -1 in seed line, S2 - S1 + MgSO 4 10 kg ha -1 in seed line, S3 - S1 + MgSO 4 25 kg ha -1 in seed line, and S4 - MgSO 4 25 kg ha -1 in seed line + foliar nutrition of 1% MgSO 4 +19:19:19 + 1% KNO 3 trice during flowering, boll development and boll bursting stages) besides recommended control were tested using RCBD. SSNM for 5 t ha -1 yield target and supplementary nutrition of MgSO4 both to soil and to foliage and foliar application of major nutrients (19:19:19 and KNO 3 ) (S4) recorded higher productivity efficiency (0.44 on pooled basis) and lower leaf reddening indices throughout (0.23, 0.37, 0.68 and 1.10 at 90, 105, 120 and 135 DAS, respectively pooled basis), whereas lower productivity efficiency with higher reddening indices were recorded with lowering of nutrition in commensuration with lower yield targets; 3 t ha -1 coupled with vermicompost alone (M 1 S 1 ) had higher indices (0.60, 1.16, 1.53 and 2.02 at 90, 105, 120 and at 135 DAS respectively on pooled basis) throughout among all. Keywords Bt cotton, SSNM and RDF, Cotton, Productivity efficiency Accepted: 22 July 2018 Available Online: 10 August 2018 Article Info