Studies on growth and chemical composition of tobacco varieties. IV - comparative effects of various combinations of fertilizers on economic potentialities of tobacco plants

Abstract

In two experiments, tobacco plants were treated with various combinations of ammonium nitrate (23% N) and compound C (3.5% N, 23% P and 16% K). At all levels used in experiment I, stem length and number of leaves were increased above the control values. An increase in the dry weight associated with a decrease in the ash content in leaves were also observed. With higher fertilizer levels used in experiment II, progressively greater reduction in stem length and number of leaves were apparent. Also the dry weight and ash content in leaves were variably reduced in relation to control values. All combinations of both fertilizers used, in general, variably increased the total soluble—N whereas protein—N increased, remained unaltered or decreased. In consequence, the total—N and the nicotine contents were increased in relation to control values. But, with all higher rates of fertilizer, the protein — as well as the total—N were in general variably reduced with a concomitant increase in nicotine and total soluble—N. Marked changes in the total amount and in the relative composition of the carbohydrate pool were apparent. These changes were associated with a general reduction in the chlorine content of all treated plants in the two experiments conducted. These pattern of changes observed in growth and quality components are discussed in relation to crop production and good quality of tobacco.