Eighteen spring wheat cultivars, recommended for commercial production in northern Poland, were assessed for Fusarium head blight (FHB) in natural non-epidemic conditions, from 2011 to 2013. Assessment was based on FHB incidence (proportion of heads with symptoms), disease severity (DS; proportion of bleached spikelets per head), proportion ofFusariumdamaged kernels (FDK), and spectrum ofFusariumspp. colonising the kernels. Fusarium head blight incidence and DS often differed significantly among cultivars and years. There was a strong positive correlation between FHB incidence and DS. Fusarium head blight incidence and DS were not correlated with the June–July temperatures, and were only occasionally correlated with the total June–July rainfall. There was a weak positive correlation between FHB incidence and proportion of FDK. There was a strong positive correlation between DS and proportion of FDK. The cultivar affected colonisation of kernels byFusariumspp.Fusarium poaewas the FHB pathogen isolated most often.Fusarium poaecolonised 6.0% of the kernels, on average, but up to 12.0% on individual cultivars. OtherFusariumspecies were less frequent:F. avenaceumin 5.6% of kernels,F. culmorumin 5.3%,F. tricinctumin 2.8%,F. graminearumin 1.5%, andF. sporotrichioidesin 1.2%.Fusarium equisetioccurred sporadically. The importance ofF. poaein the FHB complex is emphasised. All cultivars expressed ‘moderate FHB resistance’ if evaluated according to FHB incidence. Cultivars Arabella, Izera, Kandela, Monsun, Ostka Smolicka, and Struna expressed ‘moderate susceptibility’, and Bombona, Hewilla, Katoda, KWS Torridon, Łagwa, Nawra, Parabola, Radocha, SMH 87, Trappe, Tybalt, and Waluta expressed ‘susceptibility’ if evaluated by the proportion of FDK. Cultivars differed within the ‘moderately resistant’, ‘moderately susceptible’, and ‘susceptible’ categories. Cultivars Arabella, Izera, Kandela, Monsun, Ostka Smolicka, and Struna were the most promising and their resistance traits may be useful in FHB management.

Comparison of Disease Occurrence and Green Leaf Area (GLA) of Winter Wheat Depending on the Forecrop and Differentiated Fungicidal Protection UsedThe effect of the forecrop and differentiated chemical plant protection on the intensity of fungal leaf diseases of winter wheat were studied from 1999-2008. Five (I-V) separate experiments were conducted in Mazury (Szestno I,), Żuławy Wiślane (Lisewo II), and Powiśle (Wielgłowy III, IV and Radostowo V). The intensity of diseases varied. Powdery mildew (Blumeria graminis) was noted in relatively low or trace intensity. On the other hand, there was a large amount of necrotic leaf spot complexes caused byMycosphaerella graminicola, Stagonospora nodorum, Pyrenophora tritici-repentisandFusariumspp. In 2000, 2001 and 2003 brown rust (Puccinia recondita) was noted in high intensity. The applied treatments were very effective in reducing fungal disease on leaves. The surface of the upper leaves (Green leaf area - GLA) with no symptoms of infection and fungicide use were significantly higher than in the control. It was also found that the GLA of crops grown after oilseed rape was higher than the GLA of crops grown after wheat.

More disease symptoms were observed on the plots after wheat than after oilseed rape. Controlled treatments, applied during the period of shoot development, only limited the presence of FHB.

Influence of fungicide protection on health status and yielding of winter wheat (Otrzymano: 06.04.2005) S u m m a r yThe aim of the study was the effect of different chemical protection of winter wheat on occurrence of fungal diseases of stem base, leaves and yield as well. In 1999-2001 cultivars Roma and Kobra were tested in Lisewo and Wielgłowy in northern Poland. There was one fungicide treatment with kresoxim-methyl and epoxyconazole during phase 39-49 and two treatments, first with kresoxim-methyl + epoxyconazole in phase 32 and the second with tridemorf + epoxyconazole in phase 51-55. In 2002-2004 the experiment was continued in Wielgłowy on cultivar Kobra with protection combinations as follows: first treatment with kresoxim-methyl + epoxyconazole in phase 39-49, and the next ones with tridemorf + epoxyconazole or dimoksystrobine + epoxyconazole in phase 51-55. The highest infection was observed on cv. Kobra. Among pathogens isolated from infected stem bases, Fusarium spp. predominated, while Rhizoctonia spp. and Mollisia yallundae were less numerous. Powdery mildew was observed in relatively low or trace intensity, but complex of necrotic spots on leaves was noticed in high intensity. High occurrence of Mycosphaerella graminicola,. Phaeosphaeoria nodorum and Pyrenophora tritici-repentis as well as Fusarium spp. was observed. Fungicide treatments were very effective in reducing occurrence of the investigated pathogens. The area of upper leaves without disease symptoms (GLA) was significantly higher in combinations with fungicides.