Fusarium head blight and the negative influence of this dangerous disease is current worldwide problem. The aim of this work was the evaluation of incidence and severity of Fusarium head blight of barley according to different pre-crop in different locations of Slovakia. Occurrence of Fusarium head blight (FHB) was documented during two consecutive years in June 2011-2012 under the natural Fusarium infections in fields with spring barley (Hordeum vulgare). Observations were conducted at four different localities in four climatic regions in Slovakia. Incidence and severity of FHB were evaluated at the growth stages early milk to late milk in three replications. Each replication contained 100 spikes, the incidence of FHB was calculated as FHB index. During the observed period, the infestation of affected heads by FHB ranged from 0 - 12.67 %. The average infestation of heads was 5.16 % in 2011 and 5.42 % in 2012 year. Predominance intensity of FHB on infection heads were 5% or less in each locality. Higher FHB infestations were reached at Špačince (2011), Soblahov (2012) with higher precipitation when comparing long-term average. Conversely, the lowest FHB incidence was in locality with lowest precipitation in June (Veľké Úľany – 2011, Špačince – 2012). Important influence in the severity of FHB infection had also crop rotation. The highest FHB incidence was observed in localities where was maize use as a pre-crop (Špačince, 2011 – 12.67 %, Soblahov, 2012 – 11 %).
