Pakistan Journal of Biological Sciences1028-88801812-5735Asian Network for Scientific Information10.3923/pjbs.2000.1158.1160Ayyaz KhanMuhammad Ullah SadozaiGhazanfar AhmadKhalil 7200037The experiment was conducted to study the effect of sowing rates on the yield components and grain yield of wheat variety Punjab-98 at Agronomic Research Area, Faculty of Agriculture, Gomel University, Dora Ismail Khan during 1998-99. All sowing rates had significant effect on tillers per plot. Sowing rates higher than 100 kg ha1 increased tillers over low seed rate of 50 kg ha1. High sowing rates than 100 kg ha1 did not show any significant effect on spike length over low seed rate (50 kg ha1). Low seed rate produced more number of grains per spike over high seed rates. Sowing rates from 50 kg ha1 to 500 kg ha1 had no significant effect on 1000-grain weight. The highest seed rate did not produce the highest biological yield mainly due to plant competition for nutrients, light and air. The lowest biological yield in case of low seed rate was merely due to low plant population. The grain yield was decreased by using seed rate above 250 kg ha1. The highest grain ratio towards total dry matter production was found in plots sown at low seed rate (50 kg ha1) which can be attributed to more grains per spike. There was positive correlation between yield components and grain yield.]]>Ahmad, G., P. Shah and A. Bad,199511569573Akkaya, A.,199418161168Ayaz, S., P. Shah, H.M. Sharif and I. Ali,199915255262Ballatore, G.P., G.D. Prima and R. Sarno,19853159169Bricker, B.,1991Duncan, D.B.,195511142Khan, A.,19921992Khan, R.A.R.,19971997Khotyleva, L.V., L.I. Kudelko and L.A. Dylenok,19901990Little, M.T. and F.J. Hills,19781978pp: 250-264pp: 250-264Poswal, M.R.,19741974Read, D.W.L. and F.G. Warder,1982743336Singh, H. and R. Singh,198429129130Singh, R.V., V.K. Dubey and M.D. Vyas,1992Triticum aestivum) under late-sown condition.]]>374346Sorour, F.A. and M.A. El-Sharkawy,1976Triticum aestivum L.).]]>52732Steel, R.G.D. and J.H. Torrie,1984Yoon, E.B., Y.H. Yoon, Y.U. Kwon, K.B. Youn and M.G. Shin,1991336571