The aim of this study is to determine the percentage of loss in yield of some durum wheat varieties against wheat leaf rust, and to identify whether the slow rusting has a positive effect in limiting yield loss. The study was carried out in the field
s of experiments at Faculty of Agriculture, Aleppo University, Aleppo, Syria, 2015, included six durum wheat varieties (Cham1, Cham5, Douma1, Cham9, Beltagy and Massine).
