Abstract
Snow mould is a common disease of winter cereals in moderate and cold climatic areas. Snow mould of winter cereals has been observed sporadically in Latvia. Sharp development of this disease (caused by Microdochium nivale) was noticed in 2005-2007. The aim of the investigations was to clarify peculiarities of snow mould development depending on different agroecological conditions. Observations of snow mould incidence were carried out in the central part of Latvia - at the Study and research farm "Peterlauki" of the Latvia University of Agriculture during 2005-2008. The average incidence of snow mould was 40% (5-60%) in 2005, 31% (14-63%) in 2006, and 36% (2-95%) in 2007. The highest incidence of the disease was established for cultivar ‘Cubus’ (23-95% depending on the year and the sowing time). A moderate development of snow mould was observed for variety ‘Zentos’ (5-60%), but only 2-50% of damaged plants were found for ‘Tarso’. The main reason of sharp development of the disease was too early sowing of winter wheat, whereas late time of wheat sowing, on average, significantly decreased the development of snow mould (p<0.001). Further investigations are necessary to better understand the complex of factors which influenced wheat susceptibility against snow mould.