Pakistan Journal of Biological Sciences1028-88801812-5735Asian Network for Scientific Information10.3923/pjbs.1999.121.123Lolium perenne L.)]]>AkmalMohammad SchellbergJ. JanssensM. 1199921Grass vegetative growth is highly dependent on water and nitrogen (N) availability. The objective of the experiment was to examine the effect of partial drought under two different N levels on leaf growth and development at various nodal position of the plant. Irrigated versus non irrigated treatment significantly influenced leaf area development of all leaves developed on the different nodal position of ryegrass plant. The same effect of the water treatment was observed on leaf length and width. However, the leaf width was not as much influenced as the leaf length. The change in leaf length was found the major cause in change of leaf area development. The leaf masses are also influenced in a similar way as the leaf width by altering water supply to the crop. High N supply also contributed positively in the development of leaf area. This increase in the leaf area of the different leaves appeared on various nodes of a plant was due to the N effect on individual leaf length rather than leaf width. Leaves on the nodal position 3 were the greatest in size and weight and showed the maximum differences due to different water and N supplies. The mean leaf area, length, width and mass was increased from nod No 1 to 3 and thereafter, decreased. Nevertheless, effect of the treatments supply was almost the same with respect to their sizes.]]>Buxton, D.R.,1996593749Cosgrove, D.,198637377405Feller, U.,19901990pp: 195-222pp: 195-222Gastal, F. and C.J. Nelson,1994105191197Harper, J.E.,19941994pp: 285-302pp: 285-302Hirose, T. and M.J.A. Werger,198772520526Karrou, M. and J.W. Maranville,199417729744Monteith, J.L.,19811981pp: 23-38pp: 23-38Nelson, C.J.,19961996pp: 87-125pp: 87-125Paez, A. and M.E. Gonzalez,199587706711Parry, F.J., B.A. McKenzie and R.J. Lucas,199254135138Passioura, J.B.,19941994pp: 343-359pp: 343-359Riveros, E., V.G. de Cortazar and H. Landi,19941994pp: 205208Volenec, J.J. and C.J. Nelson,198121381385Volenec, J.J. and C.J. Nelson,198323720724