Tobacco yield and quality are affected more by nitrogen than any other element. It has been clearly shown that when the plant absorbs large amounts of the ammonium form of nitrogen, both quality and yield are reduced. 56.4 59.4 Nitrate Nitrogen increases yield, calcium content in the cured leaf and total potassium uptake. The total plant uptake of potassium is the highest of all the mineral elements. To produce the highest quality flue cured leaf the amount of potassium applied should be two to three times what is needed to produce maximum yield.
Potassium improves the quality of the leaf 's physical appearance and burning properties.
Potassium is responsible for the production of thinner, more elastic and pliable leaves with a deeper orange color. Increasing the potassium content in the flue cured leaf results in better burn rate and fire-holding capacity. The results of numerous studies shows that when chloride and sulfate are uptaken by the tobacco plant, quality is reduced to the poorest level. Sulfate actually shortens the duration of burn. The plant's need for potassium exceeds about three times that of nitrogen .