Comparison of bast fibre yield and mechanical fibre properties of hemp (Cannabis sativa L.) cultivars

High stem yield and high bast fibre content in stem are generally accepted as important properties for fibre hemp (Cannabis sativa L.). Quality demands for fibre used in the new non-woven products have not yet been defined. The Ukrainian monoecious fibre hemp cv. Uso 11 was compared with 13 other fibre hemp cultivars in 1995-1997 in Finland (latitude 60 degrees 49' N). Stem yield, stem length, stem diameter, bast fibre content in stem, bast fibre yield, proportion of primary fibre in the bast fibre and primary fibre yield are reported, as well as breaking tenacity and elongation at break of the fibres. The average stem yield of cv. Uso 11 was 5947 kg dry matter ha-1 and only dioecious cvs. Kompolti Hybrid TC and Novosadski produced significantly higher yields. The bast fibre content in the stem of cv. Uso 11 averaged 21.7%, and four other cultivars, both mono- and dioecious ones, had significantly higher content. The proportion of primary fibre in the bast fibre of cv. Uso 11 averaged 91.0%, and cultivars with significantly lower primary fibre fraction were all dioecious. The average bast fibre and primary fibre yields of cv. Uso 11 were 1301 and 1188 kg dry matter ha(-1), respectively. Only cv. Kompolti Hybrid TC produced significantly higher bast fibre and primary fibre yields. The median values for breaking tenacity and elongation at break of the fibres varied, depending on experimental year and cultivar, from 41 to 74 cN/tex and from 3.3 to 5.5%, respectively. The dioecious cultivars showed better or equivalent properties to cv. Uso 11. Because the season was too short for seed production, which is a prerequisite for obtaining the EU subsidy, dioecious hemp cultivars cannot be recommended for cultivation in Finland. However, monoecious Ukrainian cvs. Uso 11 and Uso 31 and Polish cvs. Beniko and Bialobrzeskie are suitable for the long-day growth conditions prevailing in Finland.