Анотация: The experiment was conducted in 2007 and 2008 with leek variety Starozagorski 72. Single treatment with biostimulator Aveikan was performed (2,5 L/ha) in phase 6-7 leaf of the crop and threefold in seedlings phase, one week after transplanting and 20 days after second treatment. Aveikan stimulates the growth and reproductive manifestations of the leek. The greatest increase was observed in the average weight. It is 19,64 percentage higher than the control in single treatment and in threefold - 33,93 percentage.The average stem height is 7,88 percentage higher in threefold treatment. The effect of Aveikan is strongly expressed on the reproductive manifestations in leek. The yield of seeds in the treated plants is 37,50 percentage higher than in the untreated plants. The treatment with Aveikan has no significant effect on the degree of infestation by rust (Puccinia porry) and on the density of tobacco thrips (Thrips tabaci)