Streszczenie. The aim of the study was to evaluate selected bioproducts in terms of their effects on tree growth and the presence of mycorrhizal fungi in the roots of trees of two apple cultivars, ‘Topaz’ and ‘Ariwa’, grown under greenhouse conditions. The trees were planted in rhizoboxes and grown under the following fertilization regimes: 0 – control, NPK control, manure, Micosat F, Humus UP, Humus Active + Aktywit PM, BF Amin, BF Quality, Tytanit and Vinassa. The results showed that the biostimulants: Humus UP, Humus Active and Aktywit PM produce beneficial effects on the morphological characteristics of the root system, and Micosat F on the extent of mycorrhiza formation in the roots. The bioproducts used are a safe, effective and economically viable method of fertilizing plants, limiting the use of chemical means of production and thus helping to protect the environment.

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