8Khalifa F M. Some factors influencing the development of sunflower(Helianthus annuus L.) under dry - farming systems in Sudan[ J].The Journal of Agricultural Science, 1981,97(l) :45-53.
10Jos6 F C B, Mdrio D C,Gottlieb B. Response of sunflower ( He-lianthus annuus L.) to sowing date and plant density under Mediter-ranean conditions!!J]. European Journal of Agronomy, 2004,21(3):347-356.