Hemp (Cannabis sativa L.) fibre can be used for biocomposites, textile, and many other applications.
Sowing density and harvest time are considered important crop management factors influencing fibre quantity and quality in hemp.
Current hemp varieties grown in Canada and Europe are certified to have THC levels below 0.3 percent. The certification system, originally developed in Europe to allow for the commercialization of industrial hemp, considered the ratio of CBD to THC as well as the absolute percent THC. The original THC threshold was 0.8 percent. One should still distinguish two principal large groups of varieties of Cannabis sativa, the drug type and the fibre type. In addition to this classical distinction of these two groups, botanists generally accept description consisting of three chemical types: (a) The pure drug type, high THC content (2-6 percent) and lacking CBD [cannabidiol]; (b) The “intermediate type” (predominantly THC); (c) The fibre type (THC<0.25 percent).
The Genus Cannabis: Taxonomy and Biochemistry 
Scientists, who were the first to study the genus Cannabis, clearly discerned different species. The father of plant taxonomy, Linnaeus, officially designated the Cannabis genus in 1753 when he founded the binomial system of botanical nomenclature. Linnaeus added the “sativa” appellation (literally, “sown” or “cultivated,” i.e., used in agriculture), indicating the utilitarian nature of the plant. Since his time numerous attempts have been made for a coherent taxonomy of Cannabis. Species designations have come and gone.
In 1889, botanist and plant explorer George Watt wrote about the distinction between types of Cannabis: “A few plants such as the potato, tomato, poppy and hemp, seem to have the power of growing with equal luxuriance under almost any climatic condition, changing or modifying some important function as if to adapt themselves to the altered circumstance. As remarked, hemp is perhaps the most notable example of this; hence, it produces a valuable fibre in Europe, while showing little or no tendency to produce the narcotic principle which in Asia constitutes its chief value.”
Dr. Andrew Wright, an agronomist with the University of Wisconsin’s Agriculture Experiment Station and steward of the Wisconsin hemp industry, during the first half of the twentieth century, wrote in 1918, “There are three fairly distinct types of hemp: that grown for fibre, that for birdseed and oil, and that for drugs.”
Although these early analysts discerned clear differences among hemp types, taxonomists have had a difficult problem in deciding how to reflect those differences. The key Cannabis species problem derives from the fact that there is no convenient species barrier between the varying types that would allow us to draw a clear line between them. In taxonomy, often the delineating line between species, is that they cannot cross-breed. But disparate types of Cannabis can indeed produce fertile offspring, not sexually dysfunctional “mules.” Consequently, a debate has raged within botanical circles as to how many species the genus contains.