INFLUENCE OF VARIED CULTIVATION CONDITION S ON THE DEVELOPMENT OF FIBERS OF 2 FIBER HEMP VARIETIES

In 1992 and 1993 field tests on the medium-early maturing monoecious f ibre hemp variety Felina 34 and the late maturing dioecious variety Ko mpolti Hibrid TC were performed to test the influence of the factors: spatial arrangement (150, 250 and 350 plants/m(2)) and nitrogen fertil ization (in the steps: without N, 60 kg Nma and 120 kg Nma) on the fol lowing parameters of fibre quality: primary fibre diameter and wall th ickness, fibre tenacity and composition of the fibre portion consistin g of primary and secondary fibres. Both varieties developed 7 to 8 lay ers of primary or long fibres. The layer thickness of the total primar y fibres was greater for both varieties in the precipitation rich year 1993 than in the dry year 1992 and also correspondingly greater with Kompolti Hibrid TC than with Felina 34. Also with increasing nitrogen fertilization and lower stand densities were the layer thicknesses inc reased. The increase of the primary fibre layer thickness was caused b y an increase in the primary fibre diameter. The portion of extensivel y filled primary fibres (higher rating), shown by the total primary fi bre population of the corresponding cross section cuts, was for Kompol ti Hibrid TC in both test years in total higher and more balanced, whi le Felina 34 showed, especially in 1992, thinner walled fibres. The hi ghest fertilization level also had a negative influence on the degree of fibre filling. Secondary or short fibres, which for many fields are useless, were observed in Kompolti Hibrid TC especially in 1993. Draw n from the stem dry mass the quantitative analysis resulted in 17,9 to 19,8% primary fibre content and from 5,8 to 6,7% secondary fibre cont ent. The tenacity of the fibre containing bark stripes from the middle of stems of Kompolti Hibrid TC (1993) was significantly different bet ween the three fertilization levels. The highest tenacity was to be ob served in the unfertilized level with 75,8 cN/tex and it decreased wit h increasing fertilization intensity to 69,9 resp. 63,7 cN/tex.