INFLUENCE OF TRANSPLANTING DATE, FERTILIZATION LEVEL AND TOPPING ON NICOTIN CONTENT OF TOBACCO LEAVES.

Abstract

              Main factors that affect the nicotin content of tobacco leaves include fertilization level, transplanting date, topping and suckering… The experiments have shown that the nicotin content of tobacco leaves has significantly increased when applying higher level of fertilization. The tobacco which has been transplanted in early season has the nicotin content as 3.54- 3.81% in comparison with 1.43-2.71% in the main season in the event of the same level of fertilization. The number of havestable leaves after topping has had the adverse correlation with the nicotin content. Tobacco with 24 havestable leaves has the nicotin content of 1.64%, and it increases to 1.75% in tobacco with 20 havestable leaves.

Higher fertilization increases both the nicotin content and the yield, but the percentage of dry leaves at good grades (grade 1 and grade 2) decreases slightly. In early season, with the increase of fertilization level from 50 N to 70 N/ha (N:P:K=1:1,5:2) the highest yield can be gained at the level 70 N. In comparison with the levels 50 N and 60 N, the yield at the level 70 N excceds 11% and 5.3% respectively. In the main season, the highest yield can be gained at the level of 70 N/ha with the excced of 12.0% and 4.0% as compared to the levels 50 N and 60 N.