Abstrait

Biology, Epidomiology, Ecology and Managment of stripe rust (Puccinia striiformis f.sp. tritici) disease of Wheat

Fikrte Yirga Belayineh

Stripe rust disease caused by Puccinia striiformis f.sp. tritici (Pst) is one of the biotic factors that constrained wheat production. The aim of this paper is to review life cycle, dispersal mechanism and management of stripe rust of wheat. The symptoms appear as very small chlorotic islands on infected leaves. A single uredospore is not visible with the naked eye but in masses appear yellow. Uredia are produced in stripes on the wheat leaf surface. Spores are produced in these pustules until the leaf senescence, and the teliospores form around the edges of the pustules. Urediospores of P. striiformis are dispersed by air over long distances among regions or even between continents. Rain and irrigated conditions create high moisture in the soil and in the air, thus more dew formation occurs at night, which ultimately favors disease development. Stripe rust disease development is mainly dependent on three environmental factors: moisture, temperature and wind. Moisture is responsible for germination, infection and survival of rust spores. Urediospores require moisture (dew) on the host surface for germination and infection. High relative humidity facilitates contact between the urediospores and the plant surface and also increases disease severity by triggering more urediospores to germinate. Temperature governs spore germination, the infection process, the latent period, sporulation, spore survival and host resistance. Cool weather favours stripe rust infection and disease development. Management of stripe rust through resistance is economical and environmentally safe but combination of cultural control practices with disease resistance and fungicide applications are the most effective means for wheat rust control.