شيوع بيماري زنگ زرد گندم در مزارع آبي مناطق سردسيري استان كهگيلويه و بويراحمد

Prevalence of yellow rust disease in irrigated wheat fields in the cold regions of Kohghilooye and Boyerahmad province

Boyerahmad and Dena are two cold areas of Kohghilooye and Boyerahmad province where bread wheat is cultivated as main crop. Based on investigations, yellow rust is one of the most important diseases of wheat in these areas, which appeares as epidemic in some regions. In order to determination of disease incidence, several fields were randomly selected and number of healthy and infected plants were countered in twenty areas of each field. Infection type and disease severity were also recorded at flag leaf stage using modified cobbʹs scale. First symptoms of yellow rust was observed in Dashteroom in 22 April 2005. Yellow rust disease was existed in all surveyed regions and 81.6 persent of wheat irrigated fields were contaminated with average of disease incidence 12.54±15.98 peresent. Sever epidemy was observed in Dashteroom region where 100 percent of fields were infected with average of disease incidence 37.5±18.3 persent and 80-100 S infection type and disease severity. In field triales that were done in natural infection condition and by use of mist irrigation and also furrow irrigation, all of wheat cultivated varieties including Alamot, Alvand, Dena, Omid and Shahriar showed susceptibility to yellow rust.