Effect of sowing date and plant density on the cell morphology of hemp (Cannabis sativa L.)

A range of papers report a major effect of agronomic procedures on the growth, biomass, fibre yield and fibre quality of hemp. The aim of this paper is to examine the influence of sowing date, seed density and year on histological characteristics of hemp (size of the different layers in the cross section of the stem, area of primary fibre cells and their cell lumen, size of fibre cell wall). It was realised that a higher seed density resulted in a reduction of almost all layers in the cross section of the stem. A similar effect was caused by the drought 1998, whereas the sowing date had almost no influence on the size of the various layers. The area of primary fibre cells was smaller in 1998. Sowing date and seed density did not affect the fibre cell area and area of cell lumen in the way mentioned above during the 2 years of the trial. During this period the size of cell wall was mainly determined by climatic conditions. Higher elongation and higher tensile strength of hemp planted at higher seed density is probably caused by differences in primary cell morphology.