Description: First signs are small yellow elongated pustules on the leaf that resemble rows of sewing stitches. Later these pustules break open to release a yellow-orange mass of spores. Once the infected plant matures it turns brown and looks like it’s been scorched.
Pathogen involved: Puccinia striiformis (a fungus)
Timing/Conditions: Spores germinate best in cool, wet weather in fall winter and/or spring.
Contributing factors: Higher elevation and cooler climate. Warm or hot temperatures limit the fungus’s ability to spread. Spores spread on the wind.
Management practices: Plant resistant varieties use fungicide and monitor the crop carefully when conditions are favorable for stripe rust.