Effect of protection against pathogens on yield of two breeding types of winter oilseed rape cultivars under high level of nitrogen fertilization

Abstract

The carried out studies confirmed the efficacy of chemical protection in reduction of infection caused by the following pathogens; Leptosphaeria spp.-phoma stem canker, Sclerotinia sclerotiorum-stem rot, Botryotinia fuckeliana-grey mould, Alternaria spp.-dark leaf and pod spot. In all plant protection programs the treatments were applied at the growth stage BBCH 65 which, was recommended for a control of pathogens occurring at highest intensity during the studies (S. sclerotiorum and Alternaria spp.) and it resulted in similar efficiency of protection. Plant protection also significantly affected the yield. The highest seed yield was collected from the objects protected three times during a vegetation season. The seed yield was also dependent on nitrogen fertilization level. Significant higher seed yield was achieved on objects fertilized with 220 kg N/ha. Seed yield was also influenced by cultivar and sowing density. Visby cultivar produced a significantly higher yield when sown at smaller density.