Ikterust

Ikterust, or yellow rust, is a fungal disease of cereal crops caused by Puccinia striiformis f. sp. tritici. It primarily infects wheat, and to a lesser extent barley and other grasses. The disease manifests as yellow to orange pustules arranged in alternating stripes along the leaves, leading to chlorosis and necrosis. Infected leaves lose photosynthetic capacity, which can reduce grain yield and quality, especially in susceptible varieties and under conducive weather conditions.

The pathogen propagates through wind-dispersed urediniospores. In temperate climates, cool and wet conditions during spring and early summer favor infections. The disease can overwinter in plant debris in some regions, and spores can persist in the field across seasons.

Management relies on an integrated approach. Use resistant cultivars carrying valid Yr resistance genes; rotate crops and remove volunteer hosts to lower inoculum; monitor weather and disease forecasts; apply fungicides when risk is high or infection appears, following local guidelines. Fungicide resistance management and timely applications are important.

Economic impact can be substantial in years with favorable conditions for the pathogen, leading to reduced yields and quality losses. Global distribution is most prominent in temperate regions of North America, Europe, and Asia, though outbreaks can occur elsewhere.

See also: rust diseases, Puccinia, cereal crops, plant pathology.