ANATOMICAL CHARACTERISTICS AND PROPERTIES OF KENAF STEMS (HIBISCUS CANNABINUS)

Abstract

From a kenaf plantation (Hibiscus cannabinus L.) established in North Greece, a number of stem sections were taken from three positions (base, middle and top) and cell morphology, anatomical appearance under SEM and basic technical properties were observed and determined. Kenaf plants had a maximum height of 2.53 m, with a mean basal diameter of 1.91 cm. The wood is the most abundant tissue with proportions up to 77% in cross-section area and up to 61.5% in weight. Wood proportions decrease, pith proportions increase and bark proportions remain constant from the base to the top of the stems. The dry density of stems ranged between 0.27–0.31 g /cm3, while that of wood ranged between 0.22–0.43 g /cm3 along the stems. The contents of hot water soluble extractives ranged between 10.6% and 20.4% and those of dichloromethane soluble extractives ranged between 0.7% and 1.2% for bark, wood and pith. Microscopic examination of stems and of macerated material showed that bark consists of thick and long (2,330 μm) fibres whilst pith consists of polygonal parenchymatous cells. Wood is diffuse- porous, fibres average 840 μm long, vessel members average 330 μm long and 45 μm in diameter and orthogonal parenchymatous cells are 90 μm long. Fibre lengths in both bark and wood increase from the base to the top of stem. Vessel diameters decrease from base to top, while vessel member lengths remain constant from base to middle but decrease at the top of the stem.