The Effects Of Two-step-leaf Remaining Technique On Upper Leaf Quality Of Flue-cued Tobbaco

The effects of two-step-leaf remaining techniques on the agronomic characters, upper leaf quality and economic traits were investigated by using K326 as tested variety. The main results were as follows:Under the treatments of remaining 16 and 18 leaves on the main culm and raising 4-8 branch leaves, could increase the leaf length and width on the main culm; the length of branch leaves were 57.40-65.33 cm, and the width were 22.53-24.53 cm. The treatments with raising branch leaves had good effects of decreasing the upper leaf ratio, of which, the treatments of 16 main culm leaves + 6 branch leaves and 18 main culm leaves + 6 branch leaves reduced the upper leaf ratio by 8.28% and 8.19% respectively compared with the CK, reached to the extremely significant differences. There were no significant differences in nicotine content of upper leaves among different treatments and the CK. The appearance quality of the treatments with raising branch leaves is better. Compared with the CK, the yields of treatments with 16 main culm leaves+8 branch leaves and 18 main culm leaves+8 branch leaves were increased 18.78kg/667 m2,6.13kg/667 m2 respectively but the yields of treatments with 16 main culm leaves+4 branch leaves and 18 main culm leaves+4 branch leaves were decreased 10.26kg/667 m2,17.18kg/667 m2 respectively. The output value of the CK was the highest, followed by the treatments of 18 main culm leaves+6 branch leaves and 16 main culm leaves+4 branch leaves. The average price, fine leaf ratio were higher in the CK, among the treatments with branch leaves, the treatments with fewer branch leaves were better. Conclusively, two-step-leaf remaining techniques, ie. 16-18 main culm leaves+4 branch leaves, not only decrease the upper leaf ratio and nicotine content, but also improve the upper leaf quality and increase tobacco leaf yield.