Correlating the results obtained by HPLC analysis as described in the results sections, we can say that an additional polyphenolic extract (SB1) determines an improvement of physiological processes in plants of sunflower, and influence the accumulation of secondary metabolism. The content of catechine determined in sunflower leaf is in higher concentration, as in spruce bark extract (Table 5). The supplementation of the growth medium with polyphenolic extract cause an increase in the amount of catechine in leaves, increasing the defense capability and therefore improving plant resistance, growth and development (Hagerman, 2002).