Biostimulators applied in the cultivation of plants stimulate the processes of life and increase their hardiness to stress conditions, contributing to greater and better quality of yield. One of them is Kelpak SL obtained from brown seaweed species Ecklonia maxima. The aim of experiment carried out was to assess a potential effect of Kelpak SL on bean (Phaseolus vulgaris L.) cultivar Aura yield. The trial was carried out during 2010-2011 years on the experimental field of Institute of Agricultural Sciences The State School of Higher Education in Chelm. Treatments with Kelpak were carried out in 2 different concentrations (0.2 % and 0.4%) and in two application frequencies (one application in the 2 – 3 leaves stage or two applications – first in the 2 – 3 leaves stage and second at the beginning of the bean’s blooming). Received results were compared with the control where Kelpak was not applied. The number and the weight of seeds, the number of pods and the weight of thousand seeds per 1 m2 were recorded. The beneficial effect of seaweed extract of Ecklonia maxima on the yield of beans (Phaseolus vulgaris L.) was demonstrated. The highest number and weight of seeds and number of pods were obtainment in the combination of once application with 0.2 % solution of Kelpak SL in 2010 and once application with 0.4 % solution of Kelpak SL in 2011. Application of Kelpak SL significantly increased number and weight of seeds and number of pods compared with the control where Kelpak SL was not applied.
