FIELD: postharvest treatment of grain before laying for storage. SUBSTANCE: method involves cleaning grain from contaminants; creating grain flow in the form of falling rain and creating aerosol flow of propionic acid including additive of chitosan; feeding aerosol flow through ultrasonic horn for contacting with grain flow; using specific additive as chitosan source, said additive being preparation produced by sequential extracting of Mortierella lignicola micromycet biomass with the use of non-polar extractant in above-critical state, water, alkaline, water, acid, water, alkaline, and water, followed by joining of first extract with solid residue. EFFECT: reliable storage of grain. 2 ex
