In four-year experiments, hop was treated with 7 biologically active substances in two terms during vegetation: Lignohumate max (a mixture of humic acids and fulvic acids), Lexin (a mixture of humic acids and fulvic acids enriched with auxins), Lexenzym (a mixture of humic acids and fulvic acids enriched with auxins, phytohormones and enzymes precursors), Ascophyllum nodosum seaweed extract, synthetic auxin, humic acids and fulvic acids alone. The chlorophyll content was monitored after the application both in the vine leaves and in the branch leaves. After harvesting of the hops from the individual treatments, the yield of dry hops was determined and the cones were analysed for the content of alpha bitter acids. The results show that the most effective hop treatment was the application of Lexin and Lexenzym. The Lexenzym treatment provided a yield of dry hops of 1.86 t/ha, i.e. 0.47 t/ha higher compared with untreated control. The Lexin treatment provided yield higher by 0.41 t/ha of dry hops compared with the untreated control, while the harvested cones contained the most alpha-bitter acids (4.57%).
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