Losses Assessment in some Egyptian Wheat Cultivars caused by Stripe Rust Pathogen (Puccinia striiformis)

Abstract

Seven Egyptian wheat (Triticum aestivum L.) cultivars wereevaluated at Kafr El-Hamam Agricultural Research Station,Sharkyia Governorate, Egypt, to stripe rust disease during2013/2014 and 2014/2015 growing seasons under artificialinoculation. 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 ofdisease increase (r-value) as well as yield components, i.e. estimatedand actual percentage loss of 1000 kernel weight and grainyield/feddan. All tested cultivars Gemmeiza-7, Gemmeiza-9,Gemmeiza-10, Gemmeiza-11, Sids-1, Sids-12 and Sids-13 showedsignificant differences in disease parameters and yield components.Fast disease development was observed with Sids-12, Gemmeiza-11and Gemmeiza-7 cultivars. Furthermore, they gave the highest valuesof estimated and actual percentage loss of 1000 kernel weight andgrain yield/feddan compared to the other tested cultivars. On the otherhand, stripe rust development was slow with Gemmeiza-10 andGemmeiza-9 cultivars. They gave the lowest values of estimated andactual percentage loss of the 1000 kernel weight and the grainyield/feddan. Accordingly, there were strong positive relationsbetween epidemiological parameters and yield components during thetwo seasons. The relation between FRS (%) and estimated loss (%) of1000 kernel weight and grain yield/feddan was more stable thanAUDPC, rAUDPC and r-value. Therefore, it can be concluded that theloss (%) of yield/feddan can be predicted from FRS (%). Moreover,the obtained results gave evidence to the importance of chemicalcontrol application in all cultivars against stripe rust diseaseparticularly with Sids-12, Gemmeiza-11 and Gemmeiza-7. It seemsthat these results are reasonable for the explanation of economicthreshold obtained from fungicide applications against stripe rustdisease in wheat fields in Egypt.