Physical properties of tobacco stalk fibers along the stem

To use tobacco stalks more economically and to improve their value, variation in fiber size，micro fiber angle （MFA），and the relative degree of crystallinity for fiber cells in tobacco stalk fibers along the height of the stem were studied. These were compared to industrial hemp stalks and castor stalks using an optical microscope and wide-angle X-ray diffraction. Results showed that the tobacco fiber cell had a favorable mid-length and good fiber size （The fiber length is 0.76 mm and the cell wall thickness to lumen diameter is 0.50）. Also，there was a marked difference between the variation in fiber size for the tobacco stalk and the industrial hemp and castor stalks along the height of the stem, for example, the fiber length at bottom part of tobacco is longest wihile the fiber length at midoint of castor stalk and industrial hemp stalk is shortest. MFA of the fiber cell wall at its midpoint was samller compared to the bottom and top parts（P= 0.000 1）， and the relative degree of fiber crystallinity decreased （P= 0.000 1） with the height of the tobacco stalk stem. In addition, compared to industrial hemp stalks，castor stalks，and Pinus kesiya，MFA was greater，the relative degree of crystallinity was also smaller，thus，tobacco fiber qualities were excellent and would be conducive to further study in the future.［Ch，2 tab. 9 ref.］