EVALUATION OF FLUE-CURED TOBACCO GENOTYPES FOR NITROGEN-USE EFFICIENY

Abstract

Tobacco is very sensitive to nitrogen fertilization and leaf being the economic product, nitrogen plays a key role in realizing optimum yields and quality. The nitrogen use efficiency in Northern Light Soils (NLS) area seldom exceeds 50%, hence, identification of genotypes with higher nitrogenuse-efficiency (NUE) may be a promising strategy to reduce the application of N fertilizer. A field experiment was conducted during 2011-12 crop season at CTRI Research Station, Jeelugumilli to evaluate the flue-cured tobacco genotypes for nitrogen use efficiency. Treatments includes eighteen flue-cured tobacco genotypes (16/103, Mc Nair-12, CM-12, Kanchan, TOBIOS-2, RT-31-1, RT40-1, RT-42-1, RT-46-1, RT-51-2, RT-52-3, RT-571, RT-62-1, RT-102-1, ABL-8-1, ABL-10-1, ABL-491 and NLSH-1) grown with (120 kg N/ha) and without N in three replications. Results revealed that fluecured tobacco genotypes showed differential response to applied nitrogen. The cured leaf yield of genotypes without N application ranged from 744 to 1244 kg/ha with an average of 1006 kg/ha. The yield of 18 genotypes grown with N (120 kg N/ha) varied between 1606 to 2722 kg/ha with an average of 2370 kg/ha. The genotypes which produced higher yields than the average under no nitrogen and 120 kg N/ha were considered as genotypes with higher use efficiency and high yield potential respectively. Based on that criterion, the genotypes 16/103, RT-31-1, RT-52-1, RT-57-1, RT-62-1, ABL8-1, ABL-10-1, ABL-49-1 and NLSH-1 have higher efficiency and the genotypes viz., RT-57-1, RT-512, NLSH-1, ABL-8-1, RT-42-1, ABL-49-1, RT-62-1, RT-102-1 and RT-31-1 have high yield potential. The Agronomic use efficiency (AE) of the genotypes varied between to 5.74 to 15.14 kg/kg with an average of 13.37 kg/kg. The genotypes which showed more than average AE were considered as nitrogen responsive genotypes. The genotypes viz., TOBIOS-2, RT-40-1, RT-42-1, RT-46-1, RT-51-2, RT57-1, RT-62-1, RT-102-1, ABL-8-1, ABL-49-1 and NLSH-1 showed higher responsiveness to nitrogen. The genotypes which recorded higher yield under no nitrogen and 120 kg N/ha and more AE are considered as efficient and responsive genotypes with high yield potential. From this study it can be inferred that among the flue-cured tobacco genotypes evaluated, RT-51-2, RT-57-1, RT-62-1, ABL-8-1, ABL-49-1 and NLSH-1 can be selected as nitrogen use efficient genotypes with high yield potential.