Field Scoring of Wheat Yellow Rust Disease Under Field Conditions: Germplasm Evaluation and Farmer Field Surveys

The wheat yellow rust disease remains an important menace to wheat production throughout the globe. The only efficient, environment-friendly, and economic disease management strategy is the exploitation of host resistance. However, the host resistance can be quickly overcome by the pathogen, Puccinia striiformis, due to its rapid evolution facilitated by its potential for recombination and long-distance migration along with mutation. Therefore, continuous effort of field scoring is required for both the genetic/breeding material under exploitation for variety/cultivar development and the varieties which have already been released and under cultivation at the farmer's field. Although several researchers are utilizing various scales for field scoring, we attempt to suggest a field scoring method to be easily adopted by relatively less trained researchers and covering the complexities of farmer field scoring. Although the method described could be applied to the three rusts of wheat and potentially other diseases, we mainly focus on wheat yellow rust disease.