Meeting the Challenge of Yellow Rust in Cereal Crops - ICARDA

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Influence of yellow rust on photosynthesis indices of wheat
E.R. Ibragimov and A.A. Zamanov
Scientific Research Station of Farming, Baku, Azerbaijan
Yellow rust is an important disease causing substantial economic loss in
Azerbaijan. Sustainable management of yellow rust is a key strategy for
improving wheat yield in the country. In order to manage this disease, better
understanding is needed of the mechanisms of damage caused by yellow rust
to the physiology of the wheat plant. The yellow rust pathogen causes
morphological and physiological changes in wheat plants, which results in
yield reductions. A study was conducted to determine the role of yellow rust
on the physiology of four wheat cultivars—Ekinci 84, Gaymetli, Kirmizygul
and Azemetli 9—differing in their levels of yellow rust resistance. The
experiment was conducted under natural infection challenge from yellow rust.
To determine the effect of disease, half of the experimental plots were sprayed
with 25% Tilt to control yellow rust. Photosynthesis indices were measured
from heading to milk stage of wheat plants, using an infrared gas analyser. The
amount of CO 2 was measured in leaf tissues. Yellow rust appeared at heading
stage in susceptible varieties. The assimilated СО 2 levels reached 9–14, 22–28,
31–39 and 43–45% at heading, flowering, grain formation and milk stages,
respectively. There were large genotypic differences among the cultivars for
photosynthesis indicators. Different levels of infection resulted in yield
reductions from 5 to 15%. The results indicated that the influence of yellow
rust on wheat productivity was greater than brown rust under Azerbaijan
conditions, because yellow rust damage lasted longer on the crop than brown
rust. The findings of this study are important for developing a wheat yellow
rust management strategy.