Asian Journal of Plant Sciences1682-39741812-5697Asian Network for Scientific Information10.3923/ajps.2006.543.546Abdol-Amir Rahnema Abdol-Mehdi Bakhshandeh 3200653The Mediterranean environment in Khuzestan province in the south of Iran is characterizing by over 30°C air temperature and heavy rainfall in early spring. Base on canola planting date, late production and ripening stages interference with high temperature, which result in limited seed yield. A experiment was conducted in Safi-Abad Agricultural Research Center for two years (2001-2003) with split - plot method and four replications. Three irrigation levels as spring irrigation cut off (SIC), one and two spring irrigation (OSI, TSI) and four varieties, i.e., Hayola 308 (H308), Hayola 401 (H401), PF7045/91 (PF) and Option 500 (OP), were examined in main and subplots respectively. Planting to flowering initiation period were completed before water stress started. The varieties in SIC, OSI and TSI treatments could tolerate 10.3, 9.8 and 9.8 days drought periods at 14, 20 and 38 seed ripening percent stages. Pods per plant, seed and oil yield decreased as water stress increased, however, water stress did not affect seed number per pod. Pods per plant, thousands seed weight, seed and oil yield in the earliest maturity variety (H308) in SIC were also decreased compared to TSI treatment by 8.0, 6.6, 8.8 and 2.7% . The results for the latest maturiting cultivar (PF) were 26.6, 10.7, 23.2 and 9.5%, respectively. Finally the results showed that earliest maturiting hybrids with drought escape mechanism are more adapted to water stress condition in this environment . Mid maturity Varieties in case of availability of one or two spring irrigation could be recommended, but the late maturity varieties such as PF for this environment are not advised.]]>Angadi, S.V., H.W., Cutforth, B.G. McConkey and Y. Gan,20034313581366Angadi, S.V., H.W. Cutforth, P.R. Miller, B.G. McConkey, M.H. Entz, A. Brandt and K.M. Olkmar,2000Brassica species to high temperature stress during reproductive growth.]]>80693701Degenhardt, D.F. and Z.P. Kondra,1981Brassica napus L.).]]>61175183Loardner, B.R., D.C. Nielsen and C.C. Shock,19925466475Gunasekera, C.P., L.D. Martin, R.J. French, K.H.M. Siddigue and G.H. Walton,2003Brassica Juncea L.) and canola (Brassica napus L.).]]>2003Milford, G.F.I., M.N. Andersen and J.H. Thage,1996Brassica napus L.) affected by soil drying and evaporative demand.]]>4793105Mailer, R.J. and P.S. Cornish,1987Brassica napus L.) and turnip rape (B. rapa L. var. silvestris).]]>27707711Nielsen, D.C.,199710307313Rahnema, A.,20022002Smis, J.R., D.J. Solum, D.M. Wichman, G.D. Kushnk and L.E. Welty et al.,1993101520Walton, G., P. Si and B. Bowden,19971997