Evaluation of the quality of cones in three hop cultivars in relation to their position on the plant

Abstract

The aim of the investigations conducted in the years 2004–2006 in a production planta­tion of three hop cultivars was to evaluate the quality of cones depending on their position on the plant. Cones of particular cultivars (Izabella, Lomik and Marynka) were manually harvested from three heights of shoots separately: lower (up to 4 m), middle (4–5.5 m) and upper (above 5.5 m) at the time of their technical maturity. Based on these data, it was found out that the largest share of the total weight was constituted by cones collected from the middle part of the plants, followed by those from the upper (Izabella and Lomik) or lower parts (Marynka). The highest content of alpha-acids was observed in cones collected from the middle (Izabella and Marynka) and upper (Lomik) parts of the shoots, while the lowest content was reported from the bottom part. The yield of cones harvested was the highest in the Lomik cultivar plantation, whereas it was significantly lower in the Marynka and Izabella cultivars. Lomik cones had the lowest content of alpha-acids, while the Marynka cultivar was characterized by the highest amounts of alpha-acids. The alpha-acid content contributed to the yield of this component calculated per unit area: its lowest value was obtained from the Lomik cultivar and it was significantly higher in the plantations of Izabella and Marynka.