INFLUENCE OF FOLIAR FERTILIZATION AND GROWTH REGULATOR ON MILK THISTLE SEED YIELD AND QUALITY

Abstract

The effects of foliar fertilization and a growth regulator 5-tert-butyl-N-m-tolylpyrazine-2-carboxamide (MD148/II) on the growth, seed yield, and silymarin content of milk thistle (Silybum marianum Gaertn.) plants were evaluated. The study was conducted over two years at an experimental field on a slightly acid-leached cinnamonic meadow soil. The MD148/II was applied in the beginning of milk thistle flowering stage. Foliar fertilizer was applied at different plant developmental stages with different proportions of nitrogen (N), phosphorus (P), and potassium (K). Treatments with foliar fertilizer and MD148/II resulted in improvement of plant biomass, number of plant lateral shoots, flowering rate, and seed yield and the content of some active substances in milk thistle seeds. A reduction of high molecular fatty acids was observed. The increase of seed yield was a result of the flower head setting enhancement. Therefore the combined treatment of foliar fertilizer and MD148/II was efficient in elicitation milk thistle production under field conditions.

Keywords:

• 5-tert-butyl-N-m-tolylpyrazine-2-carboxamide
• silymarin
• fatty acids

ACKNOWLEDGMENTS

The study was conducted with financial support from the National Science Fund at the Ministry of Education and Science, Bulgaria, Projects CC-1504 and PISA, and by the Ministry of Education of Czech Republic (MSM002160822).

Notes

∗The numbers after C indicate the number of C atoms and the number of double bonds in fatty acids.