The influence of biofertilization on the vegetative growth, yielding and nutritional status of 'Sampion' apple trees in first years after planting

The effects of biofertilizers on the growth, yielding, and nutritional status of apple trees (in comparison with the standard mineral fertilization) was evaluated in 3-years experiment (2018-2020). The experiment included the following treatments: (i) Super Fos Dar, (ii) Polifoska 6, (iii) Super Fos Dar + fungi (Aspergillus niger, Purpureocillium lilacinum), (iv) Urea enriched with fungi, (v) Urea dose reduced to 60% enriched with fungi, (vi) Super Fos Dar + bacteria applied on their own to the soil (Bacillus sp., Bacillus amyloliquefaciens, Paenibacillus polymyxa), (vii) Super Fos Dar enriched with bacteria, (viii) Super Fos Dar 60% enriched with bacteria, (ix) Polifoska 6 enriched with bacteria, (x) Polifoska 6 60% enriched with bacteria. The application of mineral fertilizers (even in reduced doses) enriched with beneficial microorganisms enhanced the growth of apple trees. The most abundant flowering was recorded when fertilization (with Super Fos Dar) was supplemented with beneficial microorganisms applied to the soil. No significant differences in plant yielding were noted (due to damages caused by spring frosts), but the highest fruit weight was recorded in the case of the trees fertilized with microbiologically enriched Super Fos Dar.