Effect of water stress on yield and yield components for some sesame varieties and its relation with wilt disease

field experiments were carried out at Shandaweel Agricultural (South Nile Vally), ARC, Egypt, during 2002 and 2003 seasons effect of water stress [i.e. irrigation after the depletion of 25-30% soil moisture (11), irrigation after the depletion of 45-50% from moisture (12), and irrigation after the depletion of 65-70% from moisture (13)] on four sesame varieties [i.e. Giza, 32 (V,), Toshky,1 1, 3 (V3), and Sohag, 3 (V4)]. The effects of the previously factors on water relations, yield, yield components and crop tolerant were studied. is indicated that average values of water consumptive use to irrigation treatments and varieties together were 2226 and 2112 2002 and 2003 seasons respectively. Results indicated that increasing intervals (irrigation after the depletion of 65-70% from available soil reduced actual evapotranspiration by 36.2% as compared with after the depletion of 25-30%. Highest average WUE values of 0.36 and 0.35 Kg seed/m3 water resulted from 13V2 and I3V3, which can be recommended as the best of sesame for cultivating under similar condition at Shandaweel. V indicated also that the most efficient method for calculating sesame water use in Upper Egypt is Doorenbos- Pruitt formula. Significant interaction effects were found between irrigation treatments sesame varieties for number of capsules/ plant, seed weight/ plant and seed yield/ plant The best interaction effect on all characters was obtained from the t1=tments of 12 and 13 with the variety of V2 and V3. Results indicated also that maximum values of oil yield were obtained from the treatment of 12. The interaction effects were found between irrigation treatments 12 and 13 and sesame varieties V2 and V3, respectively. Wilt diseases percentage increased with increasing soil moisture content. The maximum values were obtained from I, (irrigation after depletion 25-30% from available soil moisture). Results cleared that the variety V4 was the more r tolerant to wilt diseases compared with the other varieties under study.