Pakistan Journal of Biological Sciences1028-88801812-5735Asian Network for Scientific Information10.3923/pjbs.1999.148.150KarimFazli ShahidMuhammad Gohar KhanKhalid KhanSaleem 1199921Topping stages and levels had a significant effect on the chemical composition of flue-cured virginia. Plants topped at button stage produced desirable chemical characteristics as indicated by their moderately high total nitrogen (2.06%), highest nicotine (2.07%) and potash (2.70%) contents and lowest chloride (2.71%) and reducing sugar (11.72%) contents. Plants topped at 16 leaves level also produced desirable chemical characteristics, having lowest total nitrogen (1.95%), chloride (2.73%) and reducing sugar (11.72%) contents and highest nicotine (1.98%) and potash (2.67%) contents respectively. Topping beyond button stage and above 16 leaves level resulted in undesirable chemical characteristics.]]>Anonymous,19961996Ali, N., T. Hussain, S. Akbar and M. Alam,19771123125Akehurst, B.B.,1968pp: 445-447pp: 445-447AOAC.,197011th Edn.,Pages: 1015Pages: 1015Breland, H.L., W.L. Pritckett and H.W. Lundy,195919235242Chapman, H.O. and P.F. Prett,1961Chen, Y.J. and S.Y. Chen,1985221322Donev, N.,19631549Gomez, E. and L.I. Borov,19825715Hanmer, H.R., O.E. Street and P.J. Anderson,1940433177180Lamarre, M. and V. Kozumplik,1983543138Marshal and S. Heinz,1969181111Shah, A.Q. and Z. Hussain,1991Heliothis armigera) Lepidoptera nocturda.]]>151113Shmuk, A.A.,1953Vol. 3,pp: 59pp: 59