Symptoms & Signs

Infection can occur at anytime from the one-leaf stage for as long as the plants are still green. Symptoms first appear as chlorotic patches or stripes on leaves, which is followed by rust sporulation, forming tiny yellow to orange colored rust pustules called uredia. Each uredium contains thousands of urediospores. In mass, the urediniospores appear as a yellow to orange powder. On the leaves of seedlings, uredia are distributed in patches not in stripes. Stripes are formed on the leaves of adult plants (generally after stem elongation). Depending on the level of plant resistance and the temperature, various sizes of chlorotic or necrotic patches or stripes are produced, with or without sporulation. On wheat heads, uredia normally occur on the ventral surface of the glumes, and immature kernels may become infected. The rust pathogen utilizes water and nutrients from the host plants, which can dry out plants quickly. Black telial pustules, covered by host epidermal layers, often form long streaks on leaves, leaf sheaths, and glumes in the late crop season under hot and moist conditions.

References

  • Chen, X.M. 2010. Stripe Rust. In: Bockus, W.W., et al. Compendium of Wheat Diseases and Pests. 3rd edition. APS Press. pp. 55-58.