FIELD: plant growing, agricultural chemistry. SUBSTANCE: invention proposes composition for plants protection and method for treatment of plants 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 sepedonioides 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 0.5-10000 mg/t of sowing material as measure for the total content of chitosan, arachidonic and eicosapentaenic acids. Invention allows reducing accumulation of toxic substance in agricultural crops and on soil, their transport and stress effect of toxic substances on agricultural crops also. EFFECT: improved treatment method, valuable agricultural properties of composition. 2 cl, 3 tbl, 5 ex
