Pakistan Journal of Biological Sciences1028-88801812-5735Asian Network for Scientific Information10.3923/pjbs.2000.1227.1230JanMohammad Tariq KhanSanaullah 8200038Field experiment was conducted to study the effect of N-type fertilizers on the yielding components of wheat (Triticum aestivm L.), applied at sowing, vegetative and boot stage. Spike population and number of grains per spike had a significant linear increased with increase in fertilizer levels. Grain weight remained unaffected by fertilizer levels. Types of fertilizer (Ammonium sulphate and Ammonium nitrate) had no significant effect on spike population, number of grain and 1000 grain weight. Split dose (50 kg N ha1) of fertilizer application at sowing and vegetative stage (S1 + S2) or at vegetative and boot stage (S2 + S3) significantly increased number of productive tillers per unit area. Generally 50 kg N ha1 applied at boot stage increased grain weight, while number of grains per spike showed no response to split application at any growth stage.]]>Ayoub, M., S. Guertin, S.L. Lussier and D.L. Smith,199434748756Banziger, M., B. Feil and P. Stamp,199434440446Das, D.K., T.V. Rao and D.K. Das,199314421425Geleto, T., D.G. Tanner, T. Mamo, G. Gebeyehu, G. Tilahun, M. Tekalign and G. Gebeyehu,19952617731794Kelley, K.W.,199365357Latiri, S.K., C. Aubry, T. Dore and M. Sebillotte,199223143Lathwal, O.P., S. Tej and T. Singh,199286970Mazurek, J., J. Kus and L. Maj,1992181-1825360Ragheb, H.M., R.A. Dawood and K.A. Kheiralla,19932497117Singh, R.V., V.K. Dubey and M.D. Vyas,1992Triticum aestivum) under late-sown condition.]]>374346Ugalde, E.D., R.S. Balardin, J.R. Magalhaes and E.M. Reis,1993Septoria nodorum.]]>231114Verma, V.K., R.K. Mishra and R.K. Yadav,1993619