REDUCTION IN GRAIN YIELD CAUSED BY LEAF RUST INFECTION IN SEVEN EGYPTIAN WHEAT CULTIVARS

Abstract

Leaf rust caused by Puccinia triticina, is the most a widespread foliar disease of wheat in Egypt and worldwide. Yield losses of seven wheat cultivars as affected by leaf rust infection were estimated under field conditions at El-Nubariya Agricultural Research Station, during 2013/14 and 2014/15 growing seasons. Disease severity (%) was recorded (seven days intervals),and each of final rust severity(%) area under disease progress curve (AUDPC) was calculated for the tested cultivars. Final rust severity (%) ranged from 10 % to 90 % in 2013/14 growing season, while it was ranged from in 20 % to 80 %.2014/15. Also, area under disease progress curve (AUDPC) ranged from 101.50 to 1330.0 in 2013/14 growing season, but it was ranged from 185.50 to 1225 during 2014/15 season. The losses grain yield per plot ranged from 3.89% to 32.9 during 2013/14 growing season 5 % on the check variety Giza 139.Likewise, loss in 1000 kerne weigh ranged from 3.54% to 31.24% in 2013/14 from 4.65% to 28.49% in 2014/15, relevant to the two cvs.,sids-12 and Giza139 (check variety) ,respectively. Moreover, yield losses of the other tested cultivars were in between depends on the percentages of rust severity and AUDPC values for each. While, during 2014/15 yield losses per plot ranged from 4.81 % in the wheat cultivar Sids 12 to 28.21 % in the check variety Giza 139. The amount of losses in 1000 kernel weight and plot weight were positively correlated with area under disease progress curve, which means that high levels of has-genetic resistance are needed to reduce or avoid a significant yield loss.