Scanner based image analysis to characterise the influence of agronomic factors on hemp (Cannabis sativa L.) fibre width

The potential of industrial hemp to satisfy the increasing demand for natural products is limited by the lack of accurate information on how to measure and control bast fibre quality. A number of research projects have been carried out to study how hemp fibre yield is affected by genotype X environment X management (GXEXM) interaction, however the possibility to study how GXEXM affects fibre quality is hampered by the lack of standard analytical methods that can relate fibre traits, relevant to specific end use applications, to cultivation factors. In this paper an innovative methodology to analyse bast fibre quality (i.e. fibre finessess) is presented and discussed. In particular, fibre is chemically extracted (following the Bredemann method), then mechanically opened with a coarse separator and finally fibres and fibre bundle width is determined with an automated image analysis system (Fibershape). Evaluation of fibre width with this system provided results in agreement with fibre cell diameter measurements carried out on fresh stem cross section. Being fast and cost efficient this method provides researchers with a powerful system to measure the effect of agronomic techniques (i.e. sowing density and harvesting time), plant portion, genotype and potentially retting or other post-harvest managements of the stem on fibre width, which is considered one of the most important quality traits in bast fibre.