ABSTRACT
Septoria tritici blotch (STB), caused by the ascomycete fungus Zymoseptoria tritici (formerly known as Mycosphaerella graminicola for its sexual stage and Septoria tritici for its asexual stage), is one of the most economically important pathogens of wheat worldwide. This pathogen typically does not kill the wheat plants but, under favourable conditions of cool, wet weather, its tan-coloured necrotic lesions can cover entire leaves, which removes their photosynthetic benefit to the plant. This is especially severe when lesions extend to the flag leaves, when yield losses of 50-60% are often reported. STB infection reduces test weight and quality (McKendry et al., 1995); however, the pathogen does not secrete any compounds that are toxic to humans or livestock; so, grain from infected plants is at least safe to consume.
