INFLUENCE OF BIOFERTILIZERS ON PLANT GROWTH AND RHIZOSPHERE MICROBIOLOGY OF GREENHOUSE-GROWN STRAWBERRY CULTIVARS

The aim of this study was to assess the growth and development of plants of three strawberry cultivars fertilized with selected biofertilizers under greenhouse conditions. The experiments were conducted in a greenhouse complex of the Research Institute of Horticulture in Skierniewice from February to July in 2013 and 2014. Plants of three strawberry cultivars, 'Elsanta', 'Honeoye' and 'Elkat', were planted in rhizoboxes and grown under the following fertilization regimes: O-control (no fertilization), NPK control, Micosat F (bacterial-mycorrhizal substrate), manure, Humus UP, and Vinassa. Applications of Humus UP resulted in beneficial effects on plant height, leaf surface area, leaf fresh and dry weight, the degree of mycorrhizal colonization in the roots, and on the number of spores of arbuscular mycorrhizal fungi in the rhizosphere of strawberry plants. Bio-preparations Humus UP and Vinassa also had a positive influence on the size of the root system, the total number of bacteria, including spore-forming bacteria, and the total number of filamentous fungi in the rhizosphere soil, compared with mineral NPK fertilization under greenhouse conditions.