Malarvizhi Palaniappa Pillai, Professor, Dept of SS&AC, Tamil Nadu Agricultural Univ, Lawley Road, Coimbatore-641 003, India, Sharmila Banu Santhu Mohamed, Professor, Dept. of SS&AC, Tamil Nadu Agricultural Univ, Lawley Road, Coimbatore-641 003, India, and T. Nagendra Rao, Potash and Phosphate Institute of Canada-India Programme, 33, Ashok Colony, Hyderabad-500 062, India.
On farm trials on cigar tobacco at four locations were conducted in the farmers field at the villages of Kurumanthur, Karatupalayam, Karapadi and Ottar Karatupalayam of Gobichettypalayam , Erode. Dist with a test variety Karuvazhai, KV1. There were 8 treatments non-replicated. Each plot was with the size of 100 m2 (20 m x 5 m). Different sources of fertilizers were applied for the treatments. The full dose of phosphorus was applied as basal at the time of planting. The fertilizers viz., urea, sulphate of potash (SOP), Sul-Po-Mag (SPM), Elemental Sulphur (ES), magnesium sulphate, magnesium chloride, Muriate Of Potash (MOP) and magnesium acetate will be applied as top dressing in two split doses. Half quantity of fertilizers were applied at 45 days after planting. Remaining half quantity of fertilizers were applied at 60 days after planting. Other managements like irrigation, weeding and plant protection were done according to the recommended practice in the crop production manual of Tamil Nadu Agricultural University. After maturity the tobacco crops were harvested at Karattupalayam and Kurumanthur, Alukkuli and at Ottar Karattupalayam during February and March 2003 and subjected for shade curing and the cured whole plant yield were recorded. The cured whole plant yield was higher for the addition of 60:125:250:100:150 kg N, P2O5, K2O, Mg and S ha-1 (Optimum T1) in all the four locations (3855, 4561,4592,5209,4554 kg ha-1 at Karatupalayam, Kurumanthur, Ottar karattupalayam and Karapadi respectively). Omission of either P, K, Mg individually or K+Mg+S reduced the yield of tobacco. The farmer's practice recorded higher tobacco yield than the state recommendation in all the locations except at Ottarkaratupalayam. The cured tobacco whole plant yield recorded at four different locations revealed that reported the existing recommendation of 40 kg N, 100 kg P2O5 and 100 kg K2O ha-1 to cigar tobacco is sub optimal. Hence, there is a need for upward revision of the existing blanket recommendation. The fertilizer schedule recommended for cigar tobacco to ensure maximum yield and higher net income besides improving the quality of cigar tobacco, viz., nicotine, leaf burn was 60 kg N, 125 kg P2O5, 250 kg K2O, 100 kg Mg and 150 kg S ha-1.