Stripe Rust of Small Grains

Abstract

Stripe rust was reported for the first time on barley in Arizona in 1993. Stripe rust could develop into a serious disease in Arizona if it becomes established on native grasses and weather conditions allow the fungus to proliferate. The disease is caused by the basidiomycete fungus Puccinia striiformis. Stripe rust appears as yellow orange stripes between the veins of the leaf blades. The disease increases water use, shrivels the grain, and decreases yield. The fungus is an obligate parasite because it can survive and reproduce only on live hosts. Mild winters and cooler wet weather in the spring favor development of the disease. Host plant resistance is the most effective means to manage the disease. However, the fungus evolves rapidly and different races can occur from one year to the next and might overcome resistance. A number of fungicides are labeled to control the disease but scouting and early detection are crucial for timely applications of fungicides to achieve effective control.