Scientific publications

A significant number of biologically active substances in pine wood green are water-soluble fractions, such as free amino acids which are used in the treatment of many diseases. The content and composition of free amino acids in a plant vary greatly depending on nutrient concentration. The level of amino acids in plant materials can be raised and their proportion can be changed, in accordance with a specific task, by regulating mineral nutrition of plants. Fertilization with nitrogen alone greatly increases the amount of amino acids rich in nitrogen in the organs of conifers. Arginine is the major amino acid for nitrogen storage in many conifers. The quality and quantity of free amino acids composition in the needles can vary within the crown and may depend on the date of fertilization. This is important to consider when harvesting plant materials. The authors studied the influence of fertilization date on the content of L-arginine in Scots pine needles and its distribution in the crown. The experimental site was located in the south of Karelia. The stand consisted of naturally regenerated 10-year-old Scots pine trees ( Pinus sylvestris L.). To determine the distribution of L-arginine in the crown, we added to the soil a 50 g/m 2 dose of nitrogen in the form of dry ammonium nitrate and a 0.25 g/m 2 dose of boron in the form of aqueous solution of boric acid in late August. Nitrogen and boron fertilizers were applied at the model sites during the first ten days of June, in late July and late August to optimize fertilization dates. Taking into account the ratio between the weight of needles and the weight of stems, depending on the position in the tree crown, and the distribution of L-arginine on the whorls, we recommend harvesting first and second year needles of the 2nd ­- 4th whorls of the tree. The most efficient period for fertilizing is early June, if the harvesting of pine needles enriched with L-arginine is carried out in autumn or winter.