Seven Egyptian wheat (Triticum aestivum L.) cultivars were
evaluated at Kafr El-Hamam Agricultural Research Station,
Sharkyia Governorate, Egypt, to stripe rust disease during
2013/2014 and 2014/2015 growing seasons under artificial
inoculation. The evaluation included epidemiological parameters, i.e.
final rust severity (%), area under disease progress curve (AUDPC),
relative area under disease progress curve (r-AUDPC) and rate of
disease increase (r-value) as well as yield components, i.e. estimated
and actual percentage loss of 1000 kernel weight and grain
yield/feddan. All tested cultivars Gemmeiza-7, Gemmeiza-9,
Gemmeiza-10, Gemmeiza-11, Sids-1, Sids-12 and Sids-13 showed
significant differences in disease parameters and yield components.
Fast disease development was observed with Sids-12, Gemmeiza-11
and Gemmeiza-7 cultivars. Furthermore, they gave the highest values
of estimated and actual percentage loss of 1000 kernel weight and
grain yield/feddan compared to the other tested cultivars. On the other
hand, stripe rust development was slow with Gemmeiza-10 and
Gemmeiza-9 cultivars. They gave the lowest values of estimated and
actual percentage loss of the 1000 kernel weight and the grain
yield/feddan. Accordingly, there were strong positive relations
between epidemiological parameters and yield components during the
two seasons. The relation between FRS (%) and estimated loss (%) of
1000 kernel weight and grain yield/feddan was more stable than
AUDPC, rAUDPC and r-value. Therefore, it can be concluded that the
loss (%) of yield/feddan can be predicted from FRS (%). Moreover,
the obtained results gave evidence to the importance of chemical
control application in all cultivars against stripe rust disease
particularly with Sids-12, Gemmeiza-11 and Gemmeiza-7. It seems
that these results are reasonable for the explanation of economic
threshold obtained from fungicide applications against stripe rust
disease in wheat fields in Egypt.