Supports (twines) are used in hop production to assist hop growth during the growth season. The purpose of this thesis was to compare various supports used in hop growing and review their efficiency. The main aim of the research was to determine which supports are best suited for use, taking into account their qualities and price. The supports sampled were chosen based on the results of a survey done amongst Slovenian hop growers. These supports have already been in use or have at least been tested by the Slovenian Institute of Hop Research and Brewing (SIHRB) on their experimental property. The theoretical part of this thesis consists of the following: the history of hop growing and supports, the use of supports (twines) in hop production, supports from natural fibres, supports from chemical fibres from natural polymers, and supports from synthetic fibres, the future of supports, and the removal and storage of hop plant waste (i.e. biomass left after harvesting, composed of leaves and leaf stems mixed with twines). In the experimental part of the thesis, we tested and discussed five different hop supports (twines), distinguished by their origin and qualities. The following textile-mechanical tests were conducted on the twines before their application on the hop yard (i.e. fresh twines) and after aging in the field (samples were taken at the end of the growing season): twine structure, twists, linear mass density, and tensile properties. Results show that the number of twists does not influence the tensile properties of the twine. Twines from regenerated cellulose fibres have the best tensile properties; these properties, however, worsen significantly after the twine ages in the hop field. Based on their specifications, supports from synthetic fibres display better qualities than supports from natural fibres. Supports from chemical fibres from natural polymers show comparable results to supports from synthetic fibres. The former supports also show a slight increase in specific breaking tension after aging, whilst other supports (those from natural fibres and synthetic fibres) show a decrease in specific breaking tension. Comparing the purchase price of supports, the supports from natural fibres are the most expensive, followed by supports from chemical fibres from natural polymers, with supports from synthetic fibres being the lowest in price. Based on the comparison of the qualities and current prices of supports, twines made from polylactic acid (PLA) proved to be best suited for use.
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