Pakistan Journal of Biological Sciences1028-88801812-5735Asian Network for Scientific Information10.3923/pjbs.2007.3533.3540SahinAfsin AkdiYilmaz ArslanFahrettin 1220071020In this study we initially have tried to explore the wheat situation in Turkey, which has a small-open economy and in the member countries of European Union (EU). We have observed that increasing the wheat yield is fundamental to obtain comparative advantage among countries by depressing domestic prices. Also the changing structure of supporting schemes in Turkey makes it necessary to increase its wheat yield level. For this purpose, we have used available data to determine the dynamics of wheat yield by Ordinary Least Square Regression methods. In order to find out whether there is a linear relationship among these series we have checked each series whether they are integrated at the same order or not. Consequently, we have pointed out that fertilizer usage and precipitation level are substantial inputs for producing high wheat yield. Furthermore, in respect for our model, fertilizer usage affects wheat yield more than precipitation level.]]>Basso, B. and M. Bertocco L. Sartoriand and E.C. Martinal,2007268291Bera, J.,198755163172Berument, H., N. Coskun and A. Sahin,2007218797Bluemling, B., H. Yang and C. Pahl-Wost,2007911123Vijendra Kumar Boken,20009210471053Brunt, L.,20026263267Calderini, F.D. and G.A. Slafer,199857335347Cassman, K.G., A. Dobermann, D.T. Walters and H. Yang,200328315358Chen, C., B.A. McCarl and D. Schimmelpfenning,200466239261Dewey, D.R. and K.H. Lu,195951515518Dickey, D.A. and W.A. Fuller,197974427431Dyson, T.,19999659295936Engle, R.F. and C.W.J. Granger,198755251276FAO,2003Frisby, E.M.,1951177996Furtan, W., A. Guzel, G. Karagiannis and A. Bayaner,1999pp: 21pp: 21Hardwick, R.C.,197627397398Hobbs, P.R., K.D. Sayre and J.I.O. Monastreio,19981998Houghton, J.T., F.L.G. Meira, B.A. Callander, N. Harris, A. Kattenberg and K. Maskell,19961st Edn.,Pages: 572Pages: 572Hubbard, K. and R.J. Hanks,198322698703IGC,20062006Khan, M.A., I. Hussain and M.S. Baloch,200038286Labus, M.P., G.A. Nielsen and R.L. Lawrence and D.S. Long,20022341694180Mari, J., J. Bort, G. Slafer and J.L. Araus,2007150253257McCalla, A.F.,19941994Mendelsohn, R. and A. Dinar,199914277293Miller, T. and B. Bean,19992112Overton, M.,19961996Parker, F. and L.B. Nelson,196656382388PSD,20062006Sahin, A.,20062006Sahin, A. and Y. Akdi,200721116126Schofield, R.,20072007pp: 13341515SPO,20062006Sun, L., H. Li, M.N. Ward and D. Moncunill,200746226240TCRIFC,20062006TGB.,20052005Thompson, L.,1975188535541Thurling, N.,1974B. campestris and B. napus). II. yield components.]]>25711721Usherwood, N.R.,2000843032Yucel, E. and U. Ciplak,20042004