Industrial Hemp: Renewed Opportunities for an Ancient Crop

Abstract

Hemp (Cannabis sativa L.) has been a species of value to humans for much of our history given its broad adaptation and multiple uses. The plant is thought to have originated in Eurasia but has been carried to much of the rest of the world, largely for use as a fiber crop. Declining needs for fiber and competition from other plant fiber sources began to reduce demands for hemp. In turn, concern over psychotropically potent forms of hemp (i.e., marijuana) would lead to the crop's effective prohibition during much of the 20th century. Growing recognition of the many uses for hemp beyond the traditional rope, cordage, and canvas has helped revive interest in the crop, and a majority of US states have reduced restrictions to allow research with the plant. Although hemp now appears on the verge of returning to favor in the United States, there will be much to learn to make it a viable crop competitive with other commodities. Variety and photoperiodicity, site suitability, end use (grain, fiber, or dual purposes) and management, and the interactions of these factors will have a strong impact on crop productivity and suitability for post-harvest use. In addition, the harvest and processing technologies (particularly for fibers and essential oils) that are needed to optimize the plant's value are limited or lacking in the United States. Disease and pest issues are often considered of little concern for hemp, but these likely will grow as the plant's range expands. Opportunities for he…