Abstract: Pot experiments were carried out in Central Henan to investigate the effect of nitrogen applying amount after topping on plasma pigment degradation and contents of neutral aroma components and sensory quality.Five nitrogen applying amounts were used representing different nitrogen deficit levels.The results showed that as the increase of nitrogen deficiency from 0 to 100%,the pigment degradation was hastened with increased degradation magnitude and early ripening,and the plasma pigment residues after flue-curing became reduced.When nitrogen applying amount after topping decreased to the levels of 1/4 to 1/2 of the nitrogen amount before topping,the tobacco matured at the right time with decent yellowing and remained less pigment residues after curing.The contents of neophytadiene,carotenoid catabolites,aromatic amino acid metabolites were also highest.For the treatment with nitrogen totally removed from the solution,the pigments degraded too early expressing signs of early ripening with low contents of aroma constituents in cured leaves.For the treatment with less degree of nitrogen deficiency and the no-nitrogen deficiency control,the pigment degradation were delayed with higher plasma pigment residues after flue-curing,also the contents of neutral aroma components were lower.Therefore,reduction of nitrogen applying amount at maturing stage to 1/4 to 1/2 of the pre-topping level was conducive to the formation of aroma and the increase of tobacco quality.

Key words: Flue-cured tobacco, Maturing stage, Nitrogen deficiency, Plasma pigment, Neutral aroma component

CLC Number: 

• S572