FIELD: plant growing, agricultural chemistry. SUBSTANCE: invention proposes composition used for protection of plants and method for plants treatment in manufacture of plant growing production. Method involves treatment of plants with indicated composition containing the preparation as a special addition prepared by successive extraction from biomass of micromycetus Mortierella sarnyensis with nonpolar extractant taken in supercritical state, water, alkali, water, acid, water, alkali and water followed by combination of solid residue with the first extract. Plants are treated with composition taken in the amount 0.1-20 mg/ha of planting or 0.5-10 000 mg/t of sowing material as measured for the total content of chitosan, arachidonic and eicosapentaenic acid. Invention allows to reduce accumulation of toxic substances in agricultural crops and on soil, their transport and stress effect of toxic substances on agricultural crops also. EFFECT: improved treatment method. 2 cl, 3 tbl, 5 ex
