In field experiment carried out in years 2003-2007 at the Research Station at Mochełek (53^o13’ N; 17^o51’ E) near Bydgoszcz on good rye complex soil, the effect of fertilisation (147 and 221 kg NPK∙ha^-1), plant protection (control – no plant protection, herbicide, herbicide + fungicide), and seeding density (400 and 600 grains∙m^-2) on the yield and grain technological quality of winter wheat cultivar Tonacja grown in short-time monoculture was estimated. Research showed that winter wheat cultivation in 3-year monoculture on light soil caused a significant decrease in its yield from 5.70 t∙ha^-1 in the first year of monoculture to 2.92 t∙ha^-1 and 1.73 t∙ha^-1, respectively, in the second and third year of continuous cultivation. Advantageous effect on the size and quality of the grain yield of winter wheat grown in monoculture was given by the application of herbicide Huzar 05 WG and an increase in the fertilisation dose of NPK. Single application of fungicide Alert 375 SC during vegetative growth and an increase in seeding density did not create such an effect.

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