Yellow leaf spot, also known as tan spot is a major disease of durum wheat in eastern Algeria. This disease is caused by Pyrenophora tritici-repentis, the pathogen survives between cropping seasons on cereal stubbles as mycelium and can survives up to two years when the seasons are very dry. The persistence as well as the severity of this disease may be determined by five factors: monoculture, poor tillage sensitive cultivars, the kind and application of manners fungicide treatment and the infection by other fungal pathogens. The combination of those factors may have contributed to the emergence of fungicide-resistant isolates to the triazole and strobilurin groups and, consequently, to the persistence of this disease in durum wheat fields. In the present study, each one of those factors and in combination were evaluated for their impact on the emergence of fungicidal resistant isolates of Pyrenophora tritici-repentis in eastern Algeria.

Keywords: durum wheat, tan spot, fungicides-resistance