Induction of milk thistle (Silybum marianum L. Gaertn) growth and phytochemicals production by natural stimulants

Abstract

Two field experiments were carried out through 2013/2014 and 2014/2015 seasons in Faculty of Agriculture experimental farm, Tanta University, to investigate the influence of chicken manure (CM) and yeast extract (YE) on Silybum marianum (milk thistle) growth, yield and phytochemical constituents. CM was applied to soil with rates of 0.0, 23.81, 35.71 and 47.62 m3/hectare (ha) and YE was applied after 15 and 75 days of seed sowing, with rates of 0, 25, 50 and 100 g/L as foliar spray. The design of the experiment was as split plot with CM as the main plot. Results indicated that the applied bio-stimulants improved the vegetative traits and seed yield, but without obvious effect on chlorophyll content, though both treatments had resulted in a significant enhancement in PSII photochemical efficiency. Also, both bio-stimulants possessed positive impact on the antioxidant status of seed extracts and silymarin production, as well as the phytochemical constituents. However, these treatments caused a pronounced fluctuation in amino acids profile.