The aim of the study was to determine the effect of inoculation of Virginia mallow (Sida hermaphrodita [L.] Rusby) with fungus Sclerotinia sclerotiorum [Lib.] de Bary, which causes stem rot, on the contents and distribution of aluminium, manganese and iron in the shoots of this plant. Field study was carried out during three years (2011-2013) in the soil and weather conditions of central-west Poland. Inoculation was carried out with isolates obtained from rapeseed and mallow. It consisted in a slight damage of stem epidermis and inserting wheat grain overgrown with mycelium of a given isolate. During plant growth, strong infection of mallow shoots was observed, which caused inhibition in the growth and development of the plant. At the stage of technological maturity, shoots were harvested from both the control and inoculated plots for chemical analyses. Contents of the studied elements were determinated in analytical solutions obtained from biomass ash after its “dry combustion” method, using ICP-OES spectrometer. Contents and distribution of aluminium, manganese and iron in mallow shoots depended upon plant parts and placement of pathogens on the stem. The highest amount of aluminium was found in the inoculated part, and the lowest in the apices part, regardless of isolate origin. In the case of iron and manganese distribution, statistically significant effect of the applied pathogen was found. Isolate from the mallow caused greater manganese accumulation and lower iron accumulation. The conducted study demonstrates a significant effect of infection with fungus S. sclerotiorum on the physiological processes that occur in Virginia mallow plants.

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