Wpływ ochrony fungicydami na zdrowotność i plon pszenicy ozimej [Influence of fungicide protection on health status and yielding of winter wheat]

Abstract

The 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.