Unlike other agronomic crops, industrial hemp production in the United States faces additional obstacles in form of government drug policies and the Drug Enforcement Agency (DEA) concerns about how industrial hemp may impact the illicit marijuana industry. Industrial hemp refers primarily to Cannabis sativa L. (Cannabaceae), one of the oldest cultivated crops, and a once-important source of oilseed and fiber in the US. First grown in North America in 1606, the hemp industry continued until the Marihuana Tax Act of 1938. This Act ended the legal production of hemp in the United States. In 2015, legal industrial hemp production continues to face a number of obstacles in the foreseeable future, including U.S. government drug policies and DEA concerns about the ramifications of U.S. commercial hemp production. Despite US obstacles, more than 30 countries already produce hemp as an agricultural commodity and have managed to address these concerns.

In 2013, the House of Representatives passed a version of the farm bill (H.R. 2642, Section 6605) that permitted research institutions to grow industrial hemp, if allowed under state laws where the institution is located. However, similar provisions were not included in the Senate-passed farm bill (S. 947). The Industrial Hemp Farming Act of 2015 (S.134) could permit the possible commercial cultivation of industrial hemp in the United States. These bills would amend the Controlled Substance Act of 1970 to “exclude industrial hemp from the definition of “marihuana”. Industrial hemp would mean the plant Cannabis sativa L. and any part of such plant, whether growing or not, with a delta-nine tetrahydrocannabinol concentration of not more than 0.3 percent on a dry weight basis. Deems Cannabis sativa L. to meet that concentration limit if a person grows or processes it for purposes of making industrial hemp in accordance with state law, unless the Attorney General determines that the state law is not reasonably calculated to comply with such definition.”[section 102(57)]

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Figure text: Typical architecture of categories of cultivated Cannabis sativa. Narcotic plants are generally low, highly branched, and grown well-spaced. Plants grown for oilseed were traditionally well-spaced, and the plants developed medium height and strong branching, whereas fiber cultivars are grown at high density, and are unbranched and very tall. “Dual purpose” plants are grown at moderate density, tend to be slightly branched and of medium to tall height. Recent oilseed cultivars are grown at moderate density and are short and relatively unbranched. From: Small and Marcus, 2002.

The Controlled Substance Act of 1970, the federal legislation which is currently in effect, declared all cannabis varieties, including hemp, as Schedule I controlled substances (along with heroin, LSD, peyote, and ecstacy), with the U.S. Drug Enforcement Administration (DEA) serving as the regulatory authority (Title 21 US Code Controlled Substance Act). While not making industrialized hemp production illegal, this legislation required growers or researchers to obtain a permit from the DEA.

The drug potential of Cannabis is defined and measured by the presence of delta-nine tetrahydrocannabinol (THC). THC is the fourth most popular recreational drug, after caffeine, alcohol, and nicotine, its use increasing in those states where marijuana is legal (SAHMSA.gov). Recent work has found that marijuana was 114 times less toxic than alcohol (Lachenmeier and Rehm, 2015). Although marijuana typically has a THC content of 5% to 10%, levels as high as 37% in buds have been reported (ElSohly, 2009). In contrast industrial hemp designates hemp grown for commercial non-intoxicant purposes possessing a level no higher than 0.3% THC. There is a general inverse relationship in the resin of Cannabis between the amounts of THC present and the amount of the other principal cannabinoid, CBD. Whereas most drug strains contain primarily THC and little or no CBD, fiber and oilseed strains primarily contain CBD and very little THC.

It is important to stress that industrial hemp production is solely for the production of fiber or oilseed. Although CBD cannot provide the ‘high’ associated with marijuana, interest in other CBDs for pharmacological purposes remains high. However, this purpose of Cannabis is beyond the scope of this paper and at this stage, will not be considered for industrial hemp production.

The key issue affecting industrial hemp production is the fact that marijuana and hemp are virtually indistinguishable by appearance: Althought there are key morphological differences commonly observed between hemp and marijuana, a study of 97 Cannabis strains found that chemical analysis of the THC content was the only way to distinguish between marijuana and hemp varieties (DeMeijer et al., 1992).

Literature Cited:

DeMeijer, E.P.M., H.J. van der Kamp, and F.A. van Eeuwijk, “Characterization of Cannabis Accessions with Regard to Cannabinoid Content and Relation to Other Plant Characters,” Euphytica, Vol. 62, No. 3, 1992, pp. 187-200.

FDA information available on-line at: http://www.fda.gov/regulatoryinformation/legislation/ucm148726.htm

SAMHSA (Substance Abuse and Mental Health Services) information available on-line at: http://www.samhsa.gov