Influence of diet, growth stimulators and means of protection on the productivity of milk thistle in the steppe zone of the Volga region

Abstract

The results of studies of milk thistle productivity depending on soil and climatic conditions, doses and timing of mineral fertilizers, microelements, growth stimulants, plant protection products are presented. It was revealed that the formation of the assimilation apparatus and biomass is directly related to the regime of mineral nutrition, the treatment of seeds, crops with growth stimulants and plant protection products. The maximum leaf area (48.0 thousand m²/ha) and dry biomass (4.8 t/ha) were in the phase of the beginning of fruit formation when fertilizers were applied at a dose of N₉₀P₉₀K₆₀ (1.50 t/ha), which is higher than the control (without fertilizers) by 0.6 t/ha (40.0%). In wet years, the increase in seed yield after the application of fertilizers was 1.2–1.5 times higher compared to years characterized by drought. Various doses of fertilizers had a significant effect on the oil content: at the optimal dose (N₉₀P₉₀K₆₀), it increased to 30.2%, which is 12.0% higher than in the control. The content of flavolignans at the maximum dose of fertilizers increased to 3.70%, protein - up to 23.7% compared with the control (by 2.90 and 19.1%, respectively). The apllication of the growth stimulator Gibbersib in combination with microelements (Gumat 7) against the background of mineral fertilizers contributed to more intensive growth and development of milk thistle, and also increased the germination of both laboratory and field during the entire growing season (by 5.2–8.3%) and by the time of harvesting (by 2.8–8.2%). The highest yield of milk thistle seeds (1.06 t/ha) was after application of the complex microfertilizer Humat 7 and growth stimulator, respectively, compared with the control and moderate dose.