Stripe rust appears as yellow powdery pustules on the leaf surface, arranged in stripes parallel to the veins in the leaf. It can affect plants at all stages of growth. On seedlings, pustules are scattered across the leaves in no order. Spores can be found on both the leaves and the heads of wheat plants.
Stripe rust is a more common and damaging disease in late maturing crops, but is also found as a seedling disease in areas where green host plants allow for the rust to survive over summer and initiate early infections. Infection can be severe and widespread.
Stripe rust survives over summer on plants such as barley grass and volunteer wheat. It is blown onto growing wheat crops, thereby infecting young seedlings. The spores germinate on the leaf surface and penetrate the plant directly, forming a root-like structure that is used to gather nutrients. This structure produces more spores and these can be dispersed very long distances by the wind and through physical contact throughout the season. Later in the season, these are spread onto the hosts upon which they ‘over-summer’.