Die invloed van kultivar, stikstofbemesting en tophoogte op die kwaliteit van oonddroogtabak II. Chemiese kwaliteit

The effect of cultivar, nitrogen fertilization and topping height on the quality of flue-cured tobacco. II. Chemical quality. An increasing demand for good quality flue-cured tobacco prompted research to study the effect of some cultural practices on the chemical characteristics of local kultivars. Five flue-cured tobacco kultivars (TL33, A4, OD86, OD224 and OD212) were subjected to three rates of nitrogen fertilization (70, 100 and 130 kg N ha-1) and two topping heights (14 and 18 leaves) in a field trial. An increase in N-fertilization, combined with lower topping, resulted in increased concentrations of N, K, CI and nicotine in the leaf, while sugar content decreased. The K content decreased to the top leaves of the plant, while the concentration of CI and nicotine increased from the bottom. Better quality tobacco was produced where the concentration of nicotine in the leaf was higher with a lower concentration of sugar. A poor relationship between physical and chemical properties was observed.