Growth and mineral composition of Virginia tobacco in response to mineral fertilization and biostimulants

The influence of mineral fertilization and two biostimulants (microbial inoculant Mycoplant® and protein hydrolysate (PH) Trainer®) on the growth and mineral composition of Virginia tobacco was studied in field and pot experiments on Rendzic Leptosol. The seedlings of the conventional technology (manure+mineral nitrogen fertilizer) had the highest weight and the highest concentration of N and Ca in the above-ground biomass. Biostimulants also had a positive effect on plant weight and the concentration of macro- and micronutrients. Microbial inoculant Mycoplant and PH Trainer increased seedling weight (fresh and dry) by 16.8% - 22.5% and 8% - 12%, respectively, compared to the manure treatment. The microbial inoculant containing AM fungi increased seedling N, P and Mg concentration by 8%, 9% and 13%, respectively, compared to manure treatment. The concentrations of Fe, Mn, Zn and Cu also increased when Mycoplant was applied. The application of a PH-based biostimulant Trainer resulted in higher concentration of N (by 11%) and Mg (by 4%) in seedlings. Leaf area and leaf weight (pot experiment) were positively affected by compound fertilizer application. Biostimulants Mycoplant and Trainer had a weaker positive effect on these indicators. The application of compound NPK fertilizer significantly increased the concentration of N, P and K in the leaves. Biostimulants also improved the uptake of essential nutrients by tobacco plants. The microbial inoculant significantly increased the concentration of Fe in the leaves - by 25.5% compared to the control. The concentration of N was increased by 14.3% when PH Trainer was applied.