The Effect of Foliar Spray Treatments with Various Biostimulants and Fertilisers on the Growth of M.9 Rootstock Stoolings

An experiment was conducted to compare the effect of applying half a dose of a mineral fertiliser combined with a foliar treatment with four biostimulants and two fertilisers in relation to a full dose of a mineral fertiliser. The M.9 rootstock stoolings were sprayed four times during their growth. Each year of the experiment, the height, the diameter, the fresh weight of leaves and the leaf surface area of all stoolings were measured. The efficiency of rootstocks from one mother plant was assessed. Some parameters of physiological processes as well as the content of micro- and macronutrients in the leaves were also assessed. The research results showed that the reduced dose of the mineral fertiliser with foliar treatment did not significantly decrease the growth parameters of the M.9 rootstock stoolings. Some foliar treatments, especially Bioamino Plant and Bispeed, resulted in higher fresh weight and larger leaf area of the stoolings. The treatment with the Bioamino Plant biostimulant and two foliar fertilisers resulted in parameters of the physiological processes of stoolings that were the same as or better than those in the control plants. After the foliar application of two fertilisers, the content of macronutrients in the leaves of the stoolings was usually the same as in the control. The treatment with the biostimulants resulted in a lower content of most macronutrients in the plants (N, K and Ca). The only exception was the higher magnesium content than in the control after the treatment with all biostimulants and the same phosphorus content after the treatment with most of the biostimulants. The Aminoplant and Bispeed biostimulants increased the accumulation of iron in the leaves, whereas the Basfoliar 6-12-6 fertiliser resulted in higher zinc and copper content than in the control plants.