MICRONUTRIENTS INFLUENCE ON GROWTH AND DEVELOPMENT OF TAGETES PATULA L. ON THE ZOOHUMUS PHONE

The work is devoted to the assessment of changes in biometric indices of Tagetes patula plant growth under the influence of increasing doses of pre-sowing treatments of plant seeds with saline solutions of selenium Na2SeO3·(H2O)5 and silicon Na2SiO3·(H2O)5 against the background of the introduction of a liquid extract of zoohumus, a product of the vital activity of Hermetia illucens larvae, into the substrate. The following concentrations of microelements in terms of salts were used for the treatment: Se 5–10–20–30 ppm and Si 50–100–200–300 ppm. The results of measuring the mineral composition of dry zoohumus powder, as well as regulatory changes in plant morphometry under the influence of the introduction of its 1.0% alkaline suspension into the substrate, are presented. The processes of formation of shoot height and root system length were assessed. As a result, the introduction of the zoohumus suspension in the variant with silicon reduced the growth of shoots, with an increase in the length of the root system. The highest plant biomass was obtained at a concentration of 300 ppm Si with the addition of zoohumus. Moreover, a large share in the increase in the total phytomass was due to an increase in the weight of the roots. The increase in biomass was 38% (from 6.50 to 9.00 g). Seed treatment with a silicon compound against the background of zoohumus also increased the length of the root system by 39% (from 15.36 to 21.37 cm). The weight and length of the shoots decreased. Since silicon is mainly absorbed by the roots, it can be assumed that the humic compounds included in the zoohumus contributed to the redistribution of its accumulation in the underground part of plants in the form of a chelate Si-organic group. Separate treatment of seeds with silicon at a concentration of 300 ppm showed comparable results in increasing shoot weight as when growing plants on the background of zoohumus without treating seeds with this microelement. Thus, this concentration of Si can be recommended as an additional trigger for stimulating rhizogenesis and inclusion in the composition of zoocompost. The addition of selenium at all selected concentrations and backgrounds, on the contrary, inhibited shoot growth and root development, from which it can be concluded that these concentrations should either be reduced or their less toxic nanoforms should be used.

Hermetia illucens, marigolds, biomass, zoohumus, Hermetia illucens, selenium, silicon