Bożena Cwalina-Ambroziak

The effects of biological and chemical controls on fungal communities colonising tomato (Lycopersicon esculentum Mill.) plants and soil

Abstract Tomato plants (Rumba Ożarowska cultivar) grown in the greenhouse of the University of Warmia and Mazury in Olsztyn were treated with the biological control agent Polyversum WP, the growth promoter Biochikol 020 PC, the growth regulator Asahi SL, a mycorrhizal inoculum, and the fungicide Bravo 500 SC. Untreated plants served as the control. After fruit harvest, soil, stem and root samples were collected, and fungi were isolated in the laboratory. The applied biological and chemical control agents effectively reduced the abundance of fungi, including pathogenic species, colonising tomato plants and soil. The fungicide Bravo 500 SC showed the highest efficacy. Amongst the biological control agents, Biochikol 020 PC and the mycorrhizal inoculum were most effective in controlling stem colonisation by pathogens, while Polyversum WP offered the best protection of tomato roots and soil.

The health status and yield of winter rapeseed (Brassica napus L.) grown in monoculture and in crop rotation under different agricultural production systems

ABSTRACT In a field experiment, winter rapeseed was grown in 5-year monoculture and in crop rotation (winter rapeseed, winter wheat, field peas, spring wheat and winter rapeseed). Two open-pollinated cultivars (Californium and Castille) and one hybrid cultivar (Nelson) were compared in systems with three levels of agricultural inputs, low input, medium input and high input, characterized by different rates of nitrogen and sulfur fertilization and pesticide use. The severity of sclerotinia rot (Sclerotinia sclerotiorum) and verticillium wilt (Verticillium spp.) on plants, dark spot (Alternaria spp.) and grey mold (Botrytis cinerea) on leaves and pods, as well as dry rot (Phoma lingam) on stems was evaluated during the growing season. The yield of winter rapeseed was calculated. Rapeseed grown after a 4-year break was characterized by less severe symptoms of dark spot on leaves and dry rot on stems, but more severe symptoms of grey mold on leaves and pods. The severity of dark spots on rapeseed pods (in crop rotation) was reduced with an increase in agricultural inputs. Cultivars Californium and Nelson were generally rarely infected by Verticillium spp., their leaves were less infected by Alternaria spp. and stems by Phoma spp. Nelson was the highest-yielding cultivar.

The effect of fertiliser treatments on the severity of Fusarium head blight and mycotoxin biosynthesis in winter rye

Abstract The fungi of the genus Fusarium cause Fusarium head blight (FHB), a devastating disease that reduces grain yield and quality. They also produce mycotoxins which may pose a serious threat to human and animal health. This study investigated the effects of NPK fertilisation, foliar application of Cu, Zn, and Mn, applied separately and in combination, and of the Nano-Gro® organic growth stimulator on the occurrence of FHB in cultivar Dańkowskie Diament rye based on the mycological analysis of kernels and on the concentrations of Fusarium mycotoxins in grain. The severity of FHB caused by seven species of the genus Fusarium was influenced by weather conditions in the analysed growing seasons. The applied fertilisation and the Nano-Gro® organic growth stimulator exerted varied effects on FHB development and the biosynthesis of Fusarium mycotoxins (deoxynivalenol, nivalenol, zearalenone and fumonisins) in grain. The greatest reduction in deoxynivalenol and nivalenol concentrations was noted in 2013, and the levels of moniliformin were lower in treated samples than in absolute control (untreated) samples in both years of the study. The severity of FHB positively correlated with the concentrations of zearalenone, deoxynivalenol, nivalenol, and moniliformin in the grain samples. Greater accumulation of ergosterol was noted in the rye grain harvested in 2013 than in 2012, and fertiliser treatment led to higher ergosterol concentrations than did control treatment.