Meeting the Challenge of Yellow Rust in Cereal Crops - ICARDA

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Yellow rust reaction, disease development and yield losses
in selected spring bread wheat cultivars in West Asia.
O.S. Abdalla, A.A. Yaljarouka and A. Yahyaoui
ICARDA, Aleppo, Syria.
Yellow or stripe rust, caused by Puccinia striiformis West. f.sp. tritici, is the most
important disease limiting wheat production in West Asia. Use of genetic
resistance is recognized as the most economical and environmentally sound
measure to reduce production losses from this disease. This study was
conducted over two years at Aleppo, Syria, to quantify yield losses under high
yellow rust pressure in 12 genotypes varying in their reaction to the disease.
Fungicide-protected and non-protected plots were used in a split-plot
arrangement of a randomized complete block design with three replicates.
Highly significant differences were observed among treatments and
genotypes. Yields of non-protected plots, on average, were 18% lower than
fungicide-protected plots. Yield reductions among genotypes were in the range
of 3% to 78%. Yellow rust-susceptible check-cultivars Mexipak and Cham-2
exhibited 59% and 78% yield reduction, respectively. Rate of yellow rust
disease development ranged from 1 to 27, and cultivars could be classified in
three groups, namely completely resistant, slow-rusting and susceptible, with
observed disease development rates of 1, 5 and 26, respectively. Use of slowrusting
in relation to durability of rust resistance is discussed.