Abstract: Reasonable combination chemical fertilizer with organic fertilizer which is applied traditional can significantly improve tobacco quality. Malic acid, oleic acid, and fulvic acid were used to study the effects of organic acids on quality and yield in tobacco in the trial. The main results showed that three organic acids could obviously increase P, K, total sugar, reducing sugar contents, K/Cl ratio and reducing sugar/nicotine ratio, as well as the contents of furfural, nenzaldehyde, solanone, megastigmatrienone, and neopphytidiene, the main aroma component in tobacco leaves, and these were in favor of high quality of aroma in tobacco leaves. However, the three organic acids could obviously reduce N, Cl, starch, protein and nicotine contents of flue-tobacco leaves. Those were in favor of coordinating and balancing chemical compositions of flue-cured tobacco leaves, improving quality of tobacco leaves. The effect of malic acid was better than that of fulvic acid and oleic acid. In addition, malic acid could obviously improve unit price and the proportion of the superior and secondary classes of flue-cured leaves. Fulvic acid could also improve the proportion of the superior and secondary classes, output value and yield of flue-cured leaves.

Key words: Tobacco (Nicotiana tabacum L.), Organic acid, Quality, Yield