ABSTRACT
Several diseases are known to have major impacts in wheat and barley (Tables 1 and 2). In the maritime zone of Europe, the major wheat diseases are Zymoseptoria tritici causing Septoria tritici blotch (STB) and the rust diseases leaf (brown) rust (Puccinia triticina) and yellow (stripe) rust (Puccinia striiformis) (Jørgensen et al., 2014). In other parts of the world, the major diseases are tan spot (Pyrenophora tritici-repentis), stem rust (Puccinia graminis), head blight (Fusarium spp.), crown rot (Fusarium pseudograminearum) and spot blotch (mainly Bipolaris sorokiniana). The wheat form of powdery mildew (Blumeria graminis
f. sp. tritici) is important in few places where modest temperatures and high humidity occur at the same time. Recently, wheat blast (Magnaporthe oryzae tritici) has emerged as a significant threat in South America and South Asia. In barley, the two net blotches (Pyrenophora teres f. teres and Pyrenophora teres f. maculata), scald (Rhynchosporium commune), leaf (brown) rust (Puccinia hordei), powdery mildew (Blumeria graminis f. sp. hordei) and ramularia leaf spot (RLS; Ramularia collo-cygni) are the most serious threats in most growing regions (Dewar et al., 2016). Furthermore, in diseases such as head blight, crown rot and spot blotch, the same pathogens cause disease in both wheat and barley.
