In the diploma thesis, we examined different varieties of industrial hemp (Cannabis
sativa L.). The aim was to find out which variety is best suited for the production of
cannabinoids. We selected 11 varieties for the experiment, 'Berry Blossom', 'Northwest',
'Midwest', 'CBG' and 'Enectaliana', which are feminized, and 'Carmagnola', 'Dioica 88',
'Fibranova', 'Kompolti', 'Tiborszallasi' and 'Elleta Campana', which are dioecious. The
female plants were grown in 2023 from May to September near Krško at a density of 1
plant per m2. We topped half of the plants of each variety after two weeks of growth in
the field. During the growth period, we collected 30 leaves per variety to obtain data on
the leaf area, the number of leaflets and the width of the main leaflet. After harvest (end
of September and in October), we separated the plants into stems and inflorescences
with leaves and weighed them before and after drying. The cannabinoid content in the
dry inflorescences with leaves was measured using High-performance liquid
chromatography (HPLC) technique and the GemmaCert device (NIRS technology).
Topping had no major effect on the final height of the plants, but resulted in a higher
yield of dry inflorescences with leaves in most varieties. We found that the
determination of the cannabinoid content of inflorescences with leaves with the
GemmaCert device is not accurate, as it shows too much of ⠆9-tetrahydrocannabinol
(THC) and too little of cannabidiol (CBD) in the samples compared to the HPLC
technique. The highest CBD yield in dry inflorescences with leaves was obtained from
cut plants of the 'Midwest' variety (42.5 g per plant) and the highest cannabigerol (CBG)
yield was obtained from cut plants of the 'Berry Blossom' variety (42.3 g per plant) and
of CBGo line (32.0 g per plant). Female plants of feminized varieties invested more dry
matter into inflorescences with leaves compared to the stems when compared to
dioecious female plants. The varieties differed in leaf morphometry. Feminized varieties
had on average a smaller leaf area and a leaf consisting of fewer leaflets than dioecious
varieties. The 'Berry Blossom' variety (57.69 mm) and the CBGo line (48.97 mm) had
the widest main leaflet, while there were no major differences between the other
varieties. The leaf characteristics were not related to the cannabinoid content.
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