FIELD: plant growing, agricultural chemistry. SUBSTANCE: invention proposes composition used for plants protection and method for treatment of plants in manufacture of plant 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 gracilis with polar 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 measures for the total content of chitosan, arachidonic and eicosapentaenic acids. Invention allows reducing the 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
