Bull. Spec. CORESTA Congress, Harare 1994, p. 17, A 8

Evaluation of chilean nitrates as top dressers in production of light soil flue-cured tobacco in India

Central Tobacco Research Institute (CTRI), Rajahmundry (A.P.) India
Three chilean nitrate fertilizers i.e. sodium nitrate (16-0-0), sodium potassium nitrate (15-0-14) and potassium nitrate (13-0-45) were evaluated as top dressers for light soil flue-cured tobacco by conducting bulk trials at six locations in Northern Light Soil area with calcium ammonium nitrate as control, and at three locations in Karnataka Light Soil area with ammonium sulphate as control. Observations during crop growth indicated that sodium potassium nitrate top dressed plants showed vigorous early growth compared to other top dressed plants. Application of sodium potassium nitrate as top dresser gave significantly higher cured leaf yield (1789 kg/ha) and grade index (1293 kg/ha) in Northern Light Soil area than calcium ammonium nitrate (1557 & 1069 kg/ha of cured leaf and grade index respectively). All the three chilean nitrates tested were found to be superior to ammonium sulphate with respect to cured leaf yield and grade index in Karnataka Light Soils. Physical and chemical quality parameters of leaf did not differ significantly due to top dressers. Leaf sodium in P and X positions was high in plants top dressed with sodium nitrate and sodium potassium nitrate. Soil analysis before and after crop did not reveal any substantial build up of sodium in soil due to addition of sodium nitrate or sodium potassium nitrate. Thus sodium potassium nitrate proved to be a good top dresser over calcium ammonium nitrate for flue-cured tobacco in light soils of Andhra Pradesh.