June 1, 1995
Report to the Governor’s Hemp and Related Fiber Crops Task Force
Edited by Sara McNulty, June 1995
Table of Contents
Historical Overview of Three Bast Fibers
Agronomic Aspects of Fiber Crops
Hemp License Procurement
Agronomic Feasibility of Growing Kenaf in the Southeast
[The remainder is not yet included in this file.]
Appendix A Governor’s Executive Order and Task Force
Appendix B Procedure for Hemp License Application
Appendix C Hemp Marketing Committee Summary
Appendix D BIORESOURCE HEMP SYMPOSIUM
Appendix E Hemp Bibliography
Appendix F HEMP INDUSTRIES AWARENESS
Appendix G Contacts
Most analysts forecast long-term increases in world demand for all types of fibrous materials, and some predict limitations in production capacity. New fiber crops, new industrial uses of non-wood fibers, and agricultural diversification in general are therefore subjects of widespread interest. Kentucky agriculture is not alone in efforts to pursue these possibilities, and will be required to compete with producers in other states and nations.
Kentucky history, as well as recent research in other temperate zone countries, demonstrates that hemp can be produced in the Commonwealth. Selection of adapted varieties, crop management practices, harvesting technology and several other agronomic aspects may require a significant research and development effort if hemp is to be a large scale crop. Yet there is no reason to believe that these production issues are insurmountable.
The historical advantages (for example: favorable climate, naturally fertile soils, labor supply) held by Kentucky hemp producers, particularly hemp seed producers, have been made somewhat less important by modern agronomic technology.
Hemp and kenaf may have a slight advantage over certain other annual row crops with regard to potential environmental impacts. This might result from projected requirements for less pesticide and modest reductions in soil erosion.
Currently, established markets for hemp in the U.S. are generally limited to specialty/novelty textiles, oils, foods, paper and other materials. The specialized nature of this market does not require competition with other fiber sources. The potential market size is difficult to predict, but it is unlikely to support the large acreage of a major new field crop.
Bast fibers contribute an exceedingly small fraction of world textile fiber supply, which is overwhelmingly dominated by cotton. Increasing world demand and price for cotton in recent years has generated some interest in alternative fibers. However, extraction and processing of bast fibers for high quality textiles is more difficult than for cotton. A large investment, and perhaps some technological innovation, will be required by the textile industry if bast fibers are to become competitive as mass market textiles.
Use of annual fiber crops for most paper applications for for building materials, as a substitute for wood or recycled fiber, could create a very large but relatively low value market. Crop prices above $60/ton would probably be required to interest most producers; this price might preclude extensive competition in this market. Vast quantities of fibrous waste materials (sugar cane bagasse, straw) are available world wide and would also compete for such applications.
A large and long-term USDA effort on kenaf has addressed many production and processing challenges. Infrastructure for significant utilization of kenaf fiber is beginning to develop in the southern U.S. The University of Kentucky College of Agriculture is actively investigating kenaf production. Development of this alternative fiber crop in Kentucky will be dependent on nearby location of processing facilities and a profitable market for farmers.
Legal prohibition of Cannabis cultivation is the overriding obstacle to reintroduction of fiber hemp production in Kentucky. Significant progress on agronomic, marketing, or infrastructure development is unlikely, and of relatively little importance, unless legal issues are resolved. Legislative action would be required at both the state and federal level Such consideration would likely receive strong diverse reactions from both private and public sectors.
Frequently during the past six months, many colleagues and friends have asked why I became involved with the Kentucky Governor’s Hemp and Related Fiber Crops Task Force. In response I replied, “Curiosity.” With my lifelong work in Kentucky agriculture and my academic work in folk studies, I believed this hemp project would appeal to both of my principal interests.
In 1994 my friend Billy Joe Miles told me Kentucky Governor Brereton Jones had asked him to chair a task force on the feasibility of growing hemp and related fibers as a cash crop for Kentucky farmers. Several weeks later, I called Miles and asked him if I could sit in on the next meeting; he consented and later called me with the November meeting date. A few minutes after Chairman Miles called the meeting to order, he asked me to write minutes for the meeting-and so, the adventure began.
After the meeting Miles gave me the names of several Kentucky industries to call. From December 1994 until mid-February 1995 Miles and I worked steadily gathering information about hemp. As I traversed the United States by telephone and fax, I discovered that one informant usually led to three more.
From the beginning of this project, I realized that many popular publications about hemp contain inaccurate statements; thus, separating fact from fiction presented a challenge the first month. Documented, valid information provided the key for Task Force members to reach decisions they believe will best serve Kentucky farmers. Even though many of our state’s farmers are skilled and well-informed, farmers rely on the judgments of agricultural leaders to guide them concerning new crops and cultivation practices. Throughout this project, my greatest concern has been protecting Kentucky’s small farmer.
The principal problem I confronted during this project has been the emotional response many pro-hemp supporters exhibit. Although exuberance is important when promoting a product or an idea, when emotional involvement overshadows objectivity, speakers and writers may simply lift statements out of context and use them to support various claims. After working on this project for seven months, I can assure you that everything you need to know about hemp is available at the National Agriculture Library, the Agricultural Experiment Stations, and the European Studies of bast fibers. There are no secrets; no governmental agency has destroyed needed records. Furthermore, United States industry is well-informed and extremely helpful. Other fibers discussed here work as well or better than hemp in most applications.
Mainly through telephone conversations, I have met many helpful, friendly, well-informed people. Their discussions ranged from problems with growing hemp test plots; to textile importation mishaps; to all the things that hemp, if an infrastructure were in place, could become through United States technology. I want to extend my thanks to each person involved in this project. Through sharing professional perspectives and concerns, each informant helped to provide a piece of this research project. (See Appendix G Contacts)
Throughout the course of this project seven persons deserve special recognition because they formed an integral part of my research strategies and because we became a team. Each person listed impressed me with personal integrity, professional expertise, and a remarkable sense of humor.
Billy Joe Miles, my friend and later my supervisor, allowed me the freedom to explore bast fibers in North America and abroad. He kept his fax machine connected when I showered him with research updates as well as research frustrations.
Frank Aiocio, Jr. tirelessly instructed me about key issues surrounding marketing non-wood fibers in the United States and around the world. As a hemp grower and processor in Spain, Riccio quickly dispelled inaccurate information about hemp and introduced me to the experts in the pulp and paper industry, in the non-wood fibers industries, and the United States Department of Agriculture.
Jim Claycomb and I received barrages of pro and con articles about hemp, kept each other abreast of the latest reports, compared notes, and became sounding boards for each other, occasionally trying to make sense of out nonsense. He provided me a direct guide to state government services useful to this project.
Christie Bohling, touted in the U.S. hemp industries as the queen of hemp, provided me a panorama of the hemp-related industries. Given her knowledge of and involvement with hemp products for a number of years, Bohling is acutely aware of issues facing hemp industries in the United States and communicates those issues clearly and forcefully.
Jay Jeyasingam gave me my first crash course in hemp and pulp and paper making. During his long career as pulp and paper consultant, he has worked with hemp, kenaf, and other fibers in many countries throughout the world.
Gero Leson, too, clarified many issues about German markets and research developments with flax and hemp. Leson provided hours of discussion not only about specific projects and lectures at the Frankfurt, Germany, BIORESOURCE HEMP Symposium, but also presented an objective comparison of hemp with other fibers in the European community. Conversations with Leson broadened my limited understanding of environmental issues concerning wood and non-wood fibers in the United States and Europe.
Scott Smith and I became acquainted as we flew to Minnesota the North American Industrial Hemp Forum in late March l995. Indeed, Smith’s common sense approach to hemp as a Kentucky crop proved refreshing, and his knowledge of reintroducing crops benefited me practically as a farmer considering new crops. As Smith and I planned the format for the report, he proved invaluable in keeping the focus on agriculture rather than anthropology.
Governor Brereton C. Jones and state agricultural leaders continually seek new crops that will ensure profits to Kentucky farmers, Tobacco, Kentucky’s most lucrative cash crop, faces an uncertain future in the United States. After several of Kentucky’s pro-hemp supporters approached him, Jones decided a task force should investigate the feasibility of raising hemp. Following discussions of these proposals with Kentucky’s agricultural leaders, by KKS 12.029 Governor Jones formed a Task Force to study hemp and other fiber crops. (See Appendix A Governor’s Executive Order and Task Force Membership.)
The Governor’s executive order included the following mission statement adjuring the Task Force:
1. to identify and report on the current legal use and potential legal use of hemp and related fiber crops for commercial enterprise purposes 2. to provide an overview of the historical uses of hemp and related fiber crops prior to 1937 as well as its contemporaneous legal use in other countries and corresponding programs for monitoring uses 3. to identify methods of selective breeding of hemp plants and related fiber crops for the purpose of removing or producing low levels of tetrahydrocannibinol 4. to identify and report on manufacturers in the United States which currently use hemp-based and related fiber crops 5. to determine the marketability and economic competitiveness of products made from hemp and related fiber crops and to identify the technology needed for growing and processing these plants 6. to work with the executive and legislative branches on legislation, policies, and programs for promoting a concerted effort to study hemp and related fiber crops as supplemental crops to tobacco. 7. and to develop recommendations for research programs and a budget request for continued study of the potential developmental uses for hemp and related fiber crops.
The Hemp and Related Fiber Task Force first met 23 November 1994. Chairman Billy Joe Miles appointed two committees for investigating legal issues concerning growing and marketing hemp. Chairman Miles emphasized the importance of being well informed about legal issues and stressed that test plots would be planted only with legal clearance at both federal and state levels. Before the end of that session, Miles noted that if a hemp market could not sustain Kentucky farmers, then he saw no reason to ask Kentucky’s legislature to amend statutes or seek federal permits to grow hemp test plots. In subsequent months, the Legal Committee explored state and federal laws while the Marketing Committee investigated four potential markets using hemp: fabric, pulp and paper, seed and oil, and building materials. (See Appendix C Hemp Marketing Committee Summary)
Early in March 1995 Attorney General Chris Gorman ruled that at both federal and state levels all species of Cannabis sativa L. are illegal. Gorman told Miles that because federal and state governments regard hemp as an illegal product, our Task Force could not seek a permit to raise hemp test plots. In the United States because of (a) increased concern expressed by environmental groups about forest resources and endangered species, and (b) industry’s desire to use recycled fibers and post-consumer wastes, non-wood fibers have the potential to become an important manufacturing resource. This manuscript describes the agronomics and marketing possibilities for three bast fibers that can grow in Kentucky soils: hemp, flax, and kenaf. Proponents of hemp and flax hope to revitalize these crops and develop new markets for them; kenaf supporters aspire to develop markets for this new fiber.
Historical Overview of Three Bast Fibers
Submitted by Sara McNulty
Archaeologists dispute the origins of flax. Some believe flax came from Tepe Sabz, Iran (then Mesopotamia, now Iran) 5500 to 5000 B.C.E. Seeds discovered from this period reveal a select variety and indicate irrigation as part of cultivation practice. Traces of flax were unearthed in the Swiss Lake Dwellers. By 4,000 B.C.E. Egyptians-cultivated and processed flax. Ancient records and wall carvings show laborers harvesting flax. Among the Egyptians, flax weaving varied from coarse, textured material to fine, elegant linen used in burial wrappings.
Around 1100 B.C.E. the Phoenicians introduced flax cultivation and linen weaving into western Europe. Charlemagne (AD 742-814 C.E.) issued an edict requiring every family in Belgium to grow and process flax. In the beginning this flax was used mainly for the home, but later became the heart of a sophisticated industry filled with tradition; often the business was handed down from father to son. Thus Belgium became noted for its linen industry. During the 1700s Russia began cultivating and processing flax and soon dominated the market because of large areas suitable for growing flax and, because of cheap labor.
In the United States early colonists brought flax seeds with them. In addition to home use, flax fiber and tow provided the materials needed to manufacture cotton bale covering and ties. Before long, jute replaced flax for cotton bale covering because of its strength and lower cost per unit.
The Willamette Valley of Oregon pushed to develop a flax industry even though the state offered subsidies to the farmer, production was not profitable.
During World War II, because of a flax shortage, the United States government encouraged flax cultivation and processing and provided most of the funding to build two new scutching mills. After the war the industry dwindled because of high labor costs and the absence of a large domestic market.
Although no one knows the exact origin of hemp, some scholars contend that hemp production began in central Asia; others credit China. Indeed Chinese records describe cultivating and processing hemp fiber as early as 2700 B.C.E.
Historical documents written around 470 B.C.E. mentioned that the Thracians and the Scythions used hemp for rope and cloth. As the Scythions migrated into Europe they brought hemp with them. The writings of Tragas in 1530 C.E. reveal that Europeans cultivated hemp for fiber and harvested seed for human consumption. Discorides named the plant and recorded medicinal properties
of hemp as well as fiber uses. Diaries from Spanish explorations documented that Spaniards took hemp into Chile in 1545. Even though production was small, hemp remained significant in agriculture and industry.
When explorers reached American shores, many of their accounts noted wild hemp growing in the forests. The hemp referred to in these journals was a fibrous plant Native Americans used in weaving baskets and textiles, not Cannabis sativa. Entrepreneurs experimented with several native fibers for cultivation and manufacturing. For example, Virginians promoted “silk grass” and Mississippians “enequen”. Colonists soon learned these fibers could not compete with European flax and hemp applications.
Because hemp was essential to the British maritime industry, early colonists brought seed with them to America. Fortunately, the fiber adapted to our climate and soil conditions. Colonists used the fiber in the home as well as in industry.
Although Jamestown colonists wanted to grow hemp and flax on a commercial basis, John Rolf reported that these experiments proved unsuccessful. Because Virginia Company and the English government discouraged growing tobacco, in 1619 England sent settlers to Virginia specifically to cultivate crops (flax, hemp, silk grass, and silk) other then tobacco and produce commodities. That same year through English legislation, Virginia Company tried, but failed to force colonists to grow hemp and flax, but were unsuccessful. Flax and hemp remained in cultivation, but for local use, Nevertheless, the Virginia Company officials continued to discourage tobacco growing and to promote flax and hemp. In 1663 the Assembly required farmers to plant flax and hemp, but this plan failed because of limited seed supply.
Charles II endorsed flax, hemp, and silk production rather than “the precarious and immoral tobacco industry.” Even though a number of planters from Virginia and Maryland followed this trend, the program failed. (Hopkins 1951)
Sometime in the late 1600’s Maryland, Pennsylvania, and Virginia adopted laws making hemp and other staples legal tender. Thus, production of those commodities increased, thereby relieving the money shortage.
Colonial legislation offered subsidies for the cultivation and manufacturing of flax and hemp. In 1671 Maryland offered one pound of tobacco for every pound of hemp in the colony in an effort to stop importing-commodities that could be raised and manufactured in Maryland. After 1680 England stopped trying to discourage tobacco growing, but did continue promoting fibers from the colonies so as not to be dependent on foreign countries. Massachusetts, in 1700, required cordage manufactures to use fiber raised in the colony. Other colonies began subsidy programs because England began providing subsidies to naval store producers. Some colonies offered subsidies as a means of attracting immigrants into various unsettled regions. During 1767 Georgia distributed free flax and hemp seeds as well as manuals describing harvest procedures for the fibers.
By 1775 Hemp grew in Kentucky. At first hemp mainly was used by settlers but soon an export trade developed in New Orleans. The Pickney Treaty of 1795 opened the Lower Mississippi to Kentucky trade. Loose bundles or bales of hemp were taken to The Kentucky River and shipped down river where hemp was made into rope or bagging for cotton. Because of the European Wars from 1803-1805 Congress issued the Embargo and Non-importation Acts thus stopping foreign shipments of hemp. Kentucky’s hemp industry flourished. The drought of 1854 resulted in a total crop failure and required importation of thousands of bushels of hemp seed from France for the new planting season.
This prosperous era caused American hemp and hempen products to be sold at high prices. As a result small amounts of sisal from Mexico and abaca from the Philippines, cheaper and superior in application to Kentucky grown hemp, trickled into American commerce. The Civil War devastated the Kentucky hemp industry because the industry depended on slave labor to grow and break the crop. After the war Congress provided subsidies for hemp hoping to revitalize the industry. But with the superiority of imported fibers and iron ties being used to bind bales the industry dwindled.
Between 1914 and 1933, 33 states enacted laws prohibiting growing hemp for anything other than medicinal and industrial fiber purposes. In 1937 Congress passed the Marijuana Tax Act which restricted possession to those who legally bought a tax stamp, authorized medical and industrial use.
Early in 1941, with the coming of World War II, federal authorities attempted to revitalize hemp, especially Kentucky hemp. At this time the need for hemp fiber and seed increased dramatically. Kentucky agricultural leaders hoped this renewed interest would help restore the hemp industry. Planners from the USDA and War Production Board structured a war industry instead of utilizing the small existing private industry. The United States Department of Agriculture and the Commodity Credit Corporation controlled policy.
Because of government intervention and the intensive labor it required the majority of farmers did not want to grow this crop. Thus, the industry virtually disappeared after the war. Later in 1970 the 1937 tax was repealed and the provisions of Tile 11 (The Controlled Substances Act) of P.L. 91-513, The Comprehensive Drug Abuse Prevention and Control Act of 1970, made possession of marijuana illegal except for authorized experimental purposes.
Scholars conclude kenaf originated in Africa. Historical documents mention kenaf as early as 4,000 B.C.E. in western Sudan. In Africa the plant was used for fiber and the leaves for food.
Our term kenaf probably originated with the Persians who used this word to describe the plant Hibiscus cannibinus L., which they used for pulp and fiber. In 1937 researchers Miyake and Suzuta compiled a list of 129 names for various kenaf plants. For example, in India the common name is mesta; in Taiwan, ambari. In this report, kenaf means or refers to Hibiscus cannibinus L.
In the eighteenth century, Sir William Roxburg (1759-1819) conducted experiments with kenaf in India where it was widely used as a substitute for European hemp. In India its main use was for cordage, rope, twine, and sackcloth. Between 1920-1925 the USSR conducted a massive study of fiber crops; their research proved so promising that the initial study spawned a 20 year study. The USSR introduced kenaf into China in the mid-1930s. By the late 1950s China became the world’s largest producer of kenaf fiber.
Because of the jute shortage caused by World War II, the United States began testing other fibers as substitutes in the cordage industry. At the time, both researchers and manufacturers favored kenaf because of its adaptability. In 1942 kenaf research intensified when the United States Department of Agriculture and other agencies, such as the is Cooperative Fiber Commission, embarked upon a joint study with Americans and Cubans, a study which resulted in the development of new high-yielding, disease-resistant varieties. Later, the U.S. Point IV Program in Guatemala produced photosensitive kenaf verities. Then, researchers at the Everglades Experiment Station, Belle Glade, Florida and the USDA kenaf studied 15 years additional years. (Dempsey 1975)
In 1957 the Agricultural Research Service of the USDA, Northern Utilization Research and Development Division at Peoria, Illinois, launched a study to find new fiber crops. This new crop would replace surplus crops and have potential in industrial applications. In particular the Peoria lab studied fiber crops as raw materials for pulp and paper applications. Over ten years, researchers considered 1,200 samples from 600 plant species. After considerable screening they chose six plants for further study: kenaf, bamboo, crotelaria (sunn hemp), roselle, seabassia and the sorghums. Of the six, kenaf and crotelaria proved most favorable. Because kenaf produced higher yields of solid material per acre than crotelaria, researchers selected kenaf for further study in growing and pulping (this study emphasized pulping the whole raw stalk.)
Currently the USDA continues funding kenaf research for applications using the fiber as a supplementary raw material. There are four kenaf separations plants in operation. (Atchison, 1994)
Atchison, Joseph. 1994. Present Status and Future Prospects for Use of Non-Wood Plant Fibers for Paper Grade Pulpa. AF&PA’s 1994 Pulp and Fiber Fall Seminar. Tucson, Arizona.
Dempsey, J.M. 1975 Fiber Crops. University of Florida Press. Gainsville Florida.
Hopkins, James. 1951. History of the Hemp Industry in Kentucky. University of Kentucky Press. Lexington, Kentucky.
Marshall G. 1988. Flax: Breeding and Utilization. The Commission of the European Communities. The Netherlands.
Weindling, Ludwig. 1947. Long Vegetable Fibers. Columbia University Press. New York.
Agronomic Aspects of Fiber Crops
Submitted by Scott Smith
In promoting the diversification of Kentucky agriculture, there are several good reasons to consider the potential of fiber crops. World demand for fiber is currently strong and over the long term is projected to increase in all areas of application: textiles, building materials, and paper/pulp. Fiber demand will be closely linked to global economic development. Depletion of forest resources in some regions, and competing demands on forests for habitat and wilderness preservation in other locales have raised doubts that forests will continue to provide adequate supply of pulpwood at reasonable cost. While agricultural diversification is an objective shared by most states and nations, current concerns about the future of tobacco production in Kentucky have perhaps stimulated more interest here than elsewhere.
Types of Fiber Crops: A large number of plants around the World have been used for fiber. Kirby (1963)classifies these as follows:
Seed fibers: cotton, kapok,
fibers on the seeds or inner walls of the fruit; Bast fibers: flax, hemp, jute, ramie, kenaf,
fibers from the inner bast or bark of the stem; Leaf fibers: abaca, manila hemp, henequen,
fibers from the vascular tissue of the leaves; Woody fibers: wood pulp fiber,
fibers from the stem of trees; Miscellaneous fibers: examples: coir from coconut, whisks from various stems, roots and other plant parts.
Cotton: Cotton dominates world markets for textile fiber crops (See Table). U.S. production of cotton has increased greatly over the last few years because of high prices and strong demand. Cotton production has returned to some areas of the mid-South, for example North Carolina, from which it had all but disappeared. Cotton was grown in Kentucky in the past and there may be some potential for competitive production, but only in the southwestern part of the Commonwealth. (Recent reports indicate that small areas of cotton are being planted in Kentucky this year.) This report will not deal further with cotton because of its restricted potential and because voluminous information is available from other sources on its production, processing and marketing.
World Production of Vegetable Fiber, 1992
Crop 1,000 metric tonnes
FAO (1993), from Reichert (1994)
Bast fibers: Bast fibers are currently under intensive evaluation as supplemental crops for several reasons. Some are highly productive, as a group they are suitable for a wide variety of applications, and at least three (hemp, kenaf, and flax) are potentially adaptable to commercial production in the continental U.S. These three crops will be considered in more detail in this report. None of the three can accurately be described as new crops. Kenaf has long been cultivated in Asia and Africa, and it was evaluated on an experimental basis in the U.S. during World War II. Flax and hemp have been grown in the U.S. since colonial times.
Considerations for introduction of new crops: By some indices, Kentucky already has a well diversified agricultural economy. Animal and crop production are approximately equal in gross sales. Furthermore, crop production is reasonably well balanced between grain crops and non-grains. However, non-grain crops sales are overwhelmingly dominated by tobacco. Farm sales of burley and dark tobacco have approached one billion dollars per year for much of the past decade. Concerns about the future of this crop, in the face of continuing social and political pressures and global competition, provide Kentucky with additional motivation to diversify crop production.
Few, if any, crops offer a likely alternative to tobacco with respect to agronomic, economic and sociological considerations. Tobacco is a high value, high labor, relatively low risk crop that can be profitably produced by very small and rather large land holders. Tobacco explains why Kentucky has one of the nations highest ratios of farm numbers to total population, and it has a profound effect on rural economies and communities. It is unlikely that fiber crops would be produced by nearly as many farmers, or that the return relative to out-of-pocket costs would be comparable. Because of differences in production technology and labor requirements, it is probable that only a small fraction of those now producing tobacco would be interested in fiber crops, even if market demand were sufficient.
Therefore, fiber crops should be evaluated as a supplemental opportunity to diversify farming in Kentucky rather than as an alternative to tobacco.
Given favorable conditions, adoption of new crops may be rapid and extensive. Introduction of soybean cultivation throughout the grain producing regions of the U.S. provides the most dramatic example. However, successful new crop introductions are certainly out numbered by new crops for which adoption has been unsuccessful, or extremely limited. A host of factors may act against the adoption of a new or supplemental crop. Before committing to a new crop enterprise a farmer will expect satisfactory answers to at least these questions:
How do I grow it?
What do I need to buy to grow it?
What yield can I expect?
Where am I going to sell it?
What price will it bring?
Only two of these are strictly agronomic. Innumerable production problems may limit new crop adoption: poorly adapted crop varieties, local pest problems or lack of registered chemical controls, climatic limitations, soil and fertility restrictions, incompatibility with existing cropping systems, labor requirements, production machinery unavailable or cost-prohibitive. Yet, such factors may be more easily addressed and more controllable than economic and market limitations. Success of a new crop requires coordinated development of production, markets, and all of the infrastructure required to bring crops to a market, for example; storage, transportation, and processing facilities.
Submitted by Scott smith
I. The Hemp Plant
The term hemp commonly refers both to a class of fibers and to a plant. Fibers from several plants other than true hemp are called hemp. This includes Mani
la hemp (from Musa), sunn hemp (Crotolaria) and sisal hemp (Agave). Both the plant Cannabis sativa and the fiber derived from it are often called true hemp. These various plants are related only in that they produce strong fibers which have historically been used for cordage. The discussion in this section will be limited to Cannabis sativa.
Hemp vs. marijuana: Marijuana and hemp are the same plant species, that is, Cannabis sativa L. The two terms define a difference primarily with regard to the intended application of the plant; marijuana generally designating a narcotic use and hemp designating a fiber application. Throughout this report, the terms marijuana and hemp are used in this sense. As commonly cultivated, there are differences between marijuana and fiber hemp. An appropriate analogy would be the contrast between sweet corn and corn grown for silage or feed. In both cases, genetically different varieties of a single plant species have been bred to improve characteristics for the intended application. Also in both cases, the varieties are commonly grown under different cultural conditions to favor the desired plant characteristics.
Fiber production by hemp is maximized by very dense planting. This increases the ratio of stalk to leaves and flowers.
Marijuana is best grown at a low density which favors a bushy plant with high production of leaves and flowers. Plant structure and geometry is therefore visibly different in typical fiber hemp and marijuana fields. However, isolated, individual plants of the two types cannot be reliably distinguished by sight alone.
THC: The psychoactive narcotic ingredient in Cannabis is delta-9 tetrahydrocannabinol (THC). Cultivated marijuana is commonly observed to contain 3% to 5% THC (by dry weight), but higher and lower values are possible. Selected fiber hemp cultivars now grown in Europe generally contain 1/10 or less of this concentration. In some European markets, a standard of 0.3% maximum THC content has been accepted for hemp. Genotypes of Kentucky hemp cultivated in years past are reported to be near the same range of THC content as are modern hemp varieties, but this is apparently not well documented.
Some authorities have speculated that fiber hemp with a THC concentration of 0.1% to 0.3% would have significant potential for narcotic applications. THC concentrations are commonly expressed on a whole plant basis. Selected parts of the plant (for example, buds) would have significantly higher THC levels. It should also be noted that THC might be efficiently extracted and concentrated even from low THC varieties by relatively simple methods. Also, some subjects may have a significant psychoactive response to THC concentrations of 0.1 to 0.3%.
(Communication from Dr. M.A. Elsohly, Director, National Institute of Drug Abuse Marijuana Project, University of Mississippi.)
Genetic selection of Cannabis with true zero concentration of THC and other cannabinoid compounds should be possible, either by conventional plant breeding methods or modern biotechnology approaches. In fact, it has been reported that such germplasm has been developed in some hemp breeding programs. We do not know what methods were used to measure cannabinoids in these genotypes, nor whether these results have been confirmed.
Plant structure: Hemp forms a tall, woody stem which is the basis for its value as a fiber source. Fiber hemp is typically 6 to 12 feet in height. Much taller and shorter stature has been reported; undoubtedly height will be dependent on both plant genetics and environmental conditions. The stems of many varieties are hexagonal and hollow. The complex structure of the stem includes a woody core which is high in lignin and on processing becomes the material known as hurds. The outermost layers of the stem include bark and cortex cells holding chlorophyll. Underlying the epidermis of the bark are many very long, high cellulose cells. Bundles of these cells make up the primary bast fibers of hemp.
Climatic, environmental adaptation: Cannabis will grow under a wide variety of climates ranging from the tropics to northern temperate regions. Reichert (1994) states that it grows best between 14 and 27 C, while Dempsey (1975) gives a temperature range of 13 to 22 C. It is reported to be resistant to moderate frost, and so can be planted early in northern latitudes. Most authors emphasize that humid, or at least drought-free conditions are critical for high yields.
New plantings are said to be particularly susceptible to drought damage.
A growing season of roughly 120 days was required for production of hemp for fiber in Kentucky. This is consistent with recent reports from Canada and northern Europe. Apparently, in southern Europe growing seasons may be as short as 90 days, perhaps because of selection of rapidly maturing varieties. Seed maturation requires an additional 30 to 45 days. This long season explains the continued prominence of Kentucky in hemp seed production during the first part of this century when more northerly states had become larger producers of hemp fiber. The lower probability of drought stress in some more northerly locations may continue to provide these regions with a competitive advantage over Kentucky and the South for fiber production. However, Canada and northern states would be unlikely locations for seed production.
Hemp is a short-day, photoperiod sensitive annual species. Therefore, it must be planted early (in the Northern Hemisphere) to avoid premature flowering and seed set. Most varieties are likely to mature in early fall in northern temperate regions.
Genetics: de Meijer (1994) provides a thorough and current review of Cannabis breeding, germplasm collections and genetics. There are several active germplasm collections in Europe, the largest including those at the Vavilov Research Institute in St. Petersburg, the “Fleischmann Rudolf” Agricultural Institute in Hungary, and the collection developed by de Meijer at Wageningen in The Netherlands. de Meijer refers to cultivars from France, Italy, Hungary, Rumania, Poland, and the former USSR. However, it is not clear how many of these are recent selections. Reportedly a few germplasm collections (licensed or unlicensed) are being maintained in North America but these are undoubtedly quite limited. European germplasm plus local collection of feral hemp should provide a reasonable base for initiation of breeding programs.
Hemp is dioecious; male and female flowers are typically borne on separate plants. For optimum production of the cannabinoid resins, male (staminate) plants are eliminated to prevent fertilization of the pistillate plants. For seed production male plants are greatly reduced in number. Monoecious varieties should be desirable for fiber production, and several such varieties have been developed in Europe. These should have advantages in uniformity of quality, productivity and maturity yet dioecious hemp is still produced in many parts of the World.
II. Cultivation Practices
Seeding: Dempsey (1975) reports that recommended seeding rates vary greatly with region of production, ranging from about 35 to 135 pounds per acre. This is said to result in a plant density of 19 to 70 plants per square foot. Low (1994) seeded at 50 kg/ha. This high density would be appropriate only for fiber hemp. For seed production desired plant densities would be about 1/10 as great.
Seed is typically drilled to a depth of¾ to 1 ½ inches in row spacings of 2 to 6 inches. This would require only equipment already available to most crop producers.
Early seeding is generally practiced for hemp. Dempsey indicates early to mid-March for northern temperate regions. Early April seeding was recommended for Kentucky fiber hemp, middle to late April for seed (Dep. of Agricultural Education, 1943). Early seeding would increase the probability of avoiding summer drought in Kentucky. Little information is available on seed germination characteristics and seedling establishment. Dempsey (1975) reports some benefits of seed treatment with fungicides.
Soils and fertility: Early Kentucky publications recommend growing hemp only on the best available soils, and hemp is widely regarded as being a relatively sensitive crop to soil conditions. The most important reasons for this are likely to be intolerance of soil acidity, high nitrogen demand, and relatively high water use rates, In earlier times, when lime, commercial fertilizer and irrigation were rarely used at optimal rates by crop producers, Kentucky bottom lands or upland soils rotating out of pastures were considered outstanding sites for hemp culture. Under modern soil management practices, it is possible that other regions better suited to irrigation or having deeper soils with higher water storage capacity might have some competitive advantage over Kentucky.
Some recent popular reports have suggested that hemp can be easily grown organically, without fertilizer inputs. This is unlikely. Fiber hemp has a relatively high nutrient requirement. Dempsey (1975) includes a comparison of nutrient (nitrogen, phosphorus, potassium) withdrawal by hemp versus grain crops, showing a 2 to 10 fold greater demand by hemp. The value of this comparison is limited because it appears to include the complete above ground portion of the hemp plant, but only the grain tissue for the other crops. Reichert (1994) estimates that only about 30% of the accumulated nutrients would actually be removed in harvested stalks. Nevertheless, many experiments demonstrate that optimum yields require high nitrogen availability. Response to fertilizer by hemp generally appears comparable to corn; 100 to 175 pounds of N input per acre could be anticipated for high yielding circumstances.
Some authors consider hemp to be a soil-restoring or conserving crop. Like any closely spaced plant, hemp will greatly reduce soil erosion relative to bare ground. However, like any annual crop, its production requires soil to be exposed without vegetative cover for a portion of the year. So erosion would be greater under hemp than under pasture sod or most other perennial vegetation. With regard to soil conservation characteristics, hemp might be expected to have a modest advantage over corn because of plant spacing. However, other factors, particularly the ability to use modern conservation tillage methods, would greatly outweigh this difference.
Pests, pest control: Another common claim for hemp production is that no pesticides would be needed. Most authorities do agree that cultivated hemp is not susceptible to intense pressure from insects and diseases. A few fungi and insects known to attack hemp are mentioned by Dempsey(l975), but they are considered to be minor and infrequent problems. It is interesting to wonder if the cannabinoids, like many alkaloids and secondary plant products, are associated with pest resistance. If so, the widespread culture of very low cannabinoid varieties could eventually alter disease and insect relationships.
Hemp also appears to be relatively resistant to pressure from weed competitors. This is undoubtedly related to the rapid formation of a complete, dense crop canopy early in the season. In early Kentucky agriculture, hemp was considered a valuable segment of a rotation, in part due to its function as a smother crop. Broom rape and vines are most frequently mentioned as common weeds in hemp fields. Intensive preplant cultivation was recommended in the past. Clearly one benefit of this would be to control early season weed competition. Modern producers might choose to substitute herbicides for repeated tillage/cultivation. Low (1994) grew hemp in England with no herbicides and does not expect that they will be required.
Harvesting technology: Harvesting hemp for fiber or seed traditionally has been very labor intensive. Dew retting and braking stalks, as practiced in Kentucky, called for multiple tedious manipulations of the stalks after cutting.
Harvesting requirements will vary with the anticipated end use of the hemp. Pulp and fiberboard applications would require the least amount of on-farm processing and would probably allow the use of common farm equipment, like round balers and sicklebar mowers, with minor modification. If the long bast fibers must be preserved for textile use, some onfarm processing (retting) will probably be expected, and simple forage harvesting equipment may become unsuitable. Harvest for seed will require entirely different mechanization.
Harvesting the same plants for both fiber and seed, as some have proposed, would create a substantial challenge. In addition to the widely different “maturity” dates, different machinery and on-farm processing strategies probably would be required.
III. Yields, Returns, and Costs
Yields: Under favorable conditions, hemp is a productive species capable of rapidly generating large amounts of biomass. However, contrary to the implications of some popular reports, it is no more productive than many other annual crop species, and clearly produces less biomass than corn, sugar cane and kenaf.
Most recent studies report hemp yields of 5 to 15 metric tonnes per hectare. (Ten metric tonnes per hectare equals 4.465 US tons per acre.) Jeyasingam (1995) reports 8-10 metric tonnes per hectare for hemp and 15-18 for kenaf. van der Werf (1994) places maximum yields at 15 metric tonnes per hectare and van Dam (1995) reports the range to be 10 to 15 in the Netherlands. Low (1994) reports average yields consistently around 10 tonnes per hectare for a three year study in England. Yields in Canada in a first year trial were apparently significantly less (Reichert, Personal Communication). Comparison of yields is complicated by their inconsistent expression. The results above are assumed to be on the basis of dry weight of stalks.
Historical sources for Kentucky report fiber yields of 500 to 1200 pounds per acre. This is not outside the range reported by Dempsey (1975) 370 to 1,900 kilograms fiber per hectare (330 to 1697 pounds per acre). More recently Reichert (1994) reports 900 to 2,600 kilograms fiber per hectare.
Returns: Quoted unit prices for hemp are highly variable depending on the use of the fiber and the seed variety. Raw, dry defoliated stalks are priced at 60 to 125 dollars per metric tonnes by various sources. (However, current kenaf prices are below this range.) If yields range from 7 to 15 metric tonnes/hectare, this would provide a gross return ranging widely from $420/ha to $1875/ha ($170 to $759/acre) This can be compared to a gross return for corn expected to be in the range of $200 to $350/acre in Kentucky.
Returns for separated fiber components could be significantly higher. Reichert estimates the return for raw fiber to range from $28.
barley, 4,375 (2,500 lb), 1,905, 625, 700, 3,231
corn grain, 231 (110 bu), 155, 46, 32, 233
wheat/beans, 300 (45/28 bu), 149, 44, 37, 230
tomatoes, 2,430 (27 tons), 1,278, 154, 231, 1,663 (for processing)
fiber hemp: 170-759, 184, 46, 56, 286
hemp seed: 60-800, 98, 41, 56, 195
(For hemp, see explanation of returns above and cost details see below)
For all crops except hemp, source is U.K. Dep. of Agricultural Economics, ID-99, 1993. Estimated enterprise costs for hemp production (per acre) [in US$]
Seed costs Fiber Processing certified
$/acre, $/acre, $/acre
Seed (lbs) 40, 80.00 10, 20.00 10 , 20.00
Fertilizer 33.58, 33.58, 33.58
Lime (tons) 1, 10.82 1, 10.82 I, 10.82
Fuel, oil (hrs) 4.5, 16.02 2.2, 12.22 2.2, 12.22
Repairs, 9.35, 17.60, 17.60
Interest, 7.93, 4.24, 4.24
Total, 184.12, 98.46, 98.46
Fixed costs (Depreciation, taxes, insurance)
46.08, 41.25, 64.84
Hours 8, 56.00 8, 56.00 10, 70.00
Total enterprise costs
296.20, 195.71, 233.30
Hemp costs as calculated by D. Spaulding et al.
Reichert, G. 1994. Hemp (Cannabis sativa 1.). Bi-weekly Bulletin. Agriculture and Agri-Food Canada.
Dempsey, J.M. 1975. Fiber Crops. University of Florida Press. Gainsville, Florida.
van der Werf, H.M.G. 1994. “Hemp Facts and Fiction.” Journal of the International Hemp Association. vol. 1
van Dam, H.E.G. 1995. Potentials of Hemp as Industrial Fibre Crop. Agrotechnical Research Institute, Wageningen, The Netherlands.
Leson, G. 1995. Personal communication to Governor’s Hemp and Related Fiber Crops Task Force, summarizing BIORESOURCE HEMP Symposium in Frankfurt, Germany held March 1995.
Low, I. 1994. United Kingdom Hemp Production. Publication of Hemcore LTD.
Department of Agricultural Education. 1943. Hemp Production. Ky. Miscellaneous Publication 2626. College of Education, University of Kentucky.
Jeyasingam, J. 1995. “Hemp and Kenaf in Others Countries as Applies to Kentucky.” Correspondence.
Kirby, R.H. 1963. Vegetable Fibres: Botany, Cultivation, and Utilization. Interscience Publishers, Inc., New York.
de Meijer, E. 1994. Diversity in Cannabis. Thesis, Wageningen.
Hemp License Procurement
Submitted by Sara McNulty
Task Force Chairman Billy Joe Miles authorized Scott Smith, chairman of the agronomy Department at the University of Kentucky, to explore procedures for obtaining a license to produce hemp. Smith was informed by the United States Department of Agriculture that research and teaching institutions may receive permits from the Drug Enforcement Agency (DEA) in the Department of Justice.
With help from U.S. Senator Mitch McConnell’s office and the DEA, Smith received a packet containing names of two DEA employees who could comment about the permit procedure. Subsequently contact was established with Marsha Jones at the Louisville DEA office, and she offered the following comments about permitting procedures:
DEA considers fiber hemp a class I controlled substance regardless of its THC content.
DEA concludes that anyone growing hemp must apply for registration as a manufacturer, not as a researcher. Being a manufacturer greatly increases the application costs and could reduce chances of being approved. (See Appendix B Procedure for Hemp License Application)
In addition to numerous other requirements, DEA requires that the applicant demonstrate effective controls against diversion of controlled substances.
When Smith described his plans and objectives, Jones explained that “effective controls” might normally include security fencing, alarm systems, controlled access to the site (the entire farm), and, perhaps, around-the clock armed guard. (Miles and Smith 1995.)
The United States Government Statutes
In a letter Smith received from James M. Sheahan, chief, registration unit officer of Diversion Control, with the DEA, Sheahan clarified the federal position on research with low THC hemp:
Pursuant to Title 21 , United States Code (21 USC), Section 802 (16). defines marijuana as,
all parts of the plant Cannabis Sativa L., whether growing or not; the seeds thereof; the resin extracted from any part of such plant, and every compound, manufacture, salt derivative, mixture, or preparation of such plant, its seeds or resin. Such term does not include the mature stalks of such plant, fiber produced from such stalks, oil or cake made from the seeds of such plant, any other compound, manufacture, salt, derivative, mixture, or preparation of such mature stalks (except the resin extracted therefrom), fiber, oil, or cake, or the sterilized seed of such plant which is incapable of germination.
Since marijuana is classified as a Schedule I controlled substance under the auspices of the Controlled Substances Act (CSA) and is in schedule I and IV of the Single Convention on Narcotic Drugs, its cultivation, importation, exportation, and distribution are strictly regulated in the United States and throughout the world. The Single Convention Treaty requires any marijuana (excluding fiber, seeds, and so forth) that is grown must be under the control of the federal government.
DEA has opposed the cultivation of the marijuana plant determining that it is not in the public interest to allow this growth. The prime consideration of the public interest rests with the threat of diversion associated with cultivation.
Pursuant to 21 USC 823 (a), anyone seeking to grow marijuana must apply for registration as a manufacturer. The term “manufacture” meant; the production, preparation. propagation, compounding or processing to a drug or other substances either directly or indirectly or by extraction from substances of natural origins. In order to complete the process of registration as a manufacturer of a controlled substance, DEA considers the following criteria:
I) maintenance of effective controls against diversion of particular controlled substances and any controlled substance in schedule I or II compounded therefrom into other than legitimate medical, scientific, research, or other industrial channels, by limiting the importation and bulk manufacture of such controlled substances to a number of establishments which can produce an adequate and uninterrupted supply of these substances under adequately competitive conditions for legitimate medical, scientific, research, and industrial purposes;
2) compliance with applicable state and local law;
3) promotion of technical advances in the art of manufacturing these substance and the development of new substances:
4) prior conviction record of applicant under federal and state laws relating to the manufacture, distribution, or dispensing of such substances;
5) past experience in the manufacture of controlled substances, and the existence in the establishment of effective controls against diversion, and
6) such other factors as may be relevant to and consistent with public health and safety.
Any application to manufacture marijuana must include detailed documentation regarding these requirements.
The cultivation of the marijuana plant exclusively for commercial, industrial purposes has many associated risks. For example, only the pith, lower stalks and roots of the plant do not contain the active principle during the growth of the plant. After harvesting and removal from the field, substances for misuse can be obtained from the plant. To prevent any abuse, it might be necessary to prohibit removal from the fields of any parts of the cannabis plant except the mature stalks and seeds. It might become necessary to burn the remainder. This entire process would be difficult to enforce.
Currently federal law categorizes all varieties of Cannabis sativa L. as controlled substances. (Sheahan and Smith) The following statutes cite the federal law regarding hemp, (See Appendix B Procedure for Hemp License Application)
The United States Government Statutes of 1995. Currently federal law categorizes all varieties of Cannabis sativa L. as controlled substances. The following citations state the law:
21 USC 812 © (10) – Cannabis sativa L. is a controlled substance.
21 USC 841 – The production, cultivation, or dispensing of Cannabis sativa L. is a felony.
21 USC 844 – The possession of Cannabis sativa L. is a federal offense.
Kentucky law provides no exception allowing any governmental agency to grow marijuana. (See Appendix B Procedure for Hemp License Application)
Kentucky Statutes of 1995
Kentucky statutes categorizes all varieties of Cannabis sativa L. as marijuana:
Has 218A.1422 states that a person is guilty of possession of marijuana when he knowingly and unlawfully possesses marijuana. The offense is a Class A misdemeanor.
KaS 218A.010 defines marijuana to include all parts of the plant, whether growing or not. The same statute defines person to include any government or governmental subdivision or agency.
Agronomic Feasibility of Growing Kenaf in the Southeast
Submitted by Morris Bitrer
Kenaf (Hibiscus cannibinus L.) has been grown in the United States since the 1940’s. Early USDA research focused on the development of kenaf as a cordage crop, but by the late 50’s, most of the research had changed to looking to Kenaf as a source of pulp for paper. In 1970, the USDA released a report (White et al., 1970) entitled “The Cultural and Harvesting Methods for Kenaf . . . An Annual Crop Source of Pulp in the Southeast”. The report summarized much of the research that had been done in the 60’s. Two varieties released in the mid 60’s by Florida, Everglades 41 and 71, are still two of the main varieties being grown today. Many of the cultural practices done during that period have mainly been confirmed with more recent research. The opening paragraph of this report states that “Kenaf is a promising new U.S. crop source of raw material for pulp. It is a fast-growing, productive plant with fairly wide adaptation. Excellent, high-yielding pulps are easily obtained.” Today, kenaf is being evaluated for use in newsprint, erosion mats, seeding mats, poultry litter, horse litter, waste treatment substrate, co=ercial absorbents and as a forage for livestock. (Goforth and Fuller, 1994). During the past 5 years, extensive studies on kenaf have been undertaken at many locations throughout the United States. Kenaf is now recognized as a promising alternative crop with economic potential (Zhang and Dicks, 1994). The main difference between the 60’s and the 90’s stems from pressure to reduce the use of timber and the price of wood pulp has greatly increased in relation to the cost of pulp from kenaf.
II. Current Research
Breeding and Seed Production: Extensive breeding of new kenaf varieties is well underway at Texas A & M and Mississippi State University (Cook and Mullin). The main objectives of a breeding program are to improve the disease resistance particularly to root knot nematode and to improve the yield and quality of the fiber in newer varieties. A good commercial supply of seed is now available for the first time. A major increase of Everglades 41 occurred in Mexico for the Mississippi State Foundation Seed Agency. Another large increase of several varieties was produced in the Rio Grande region of Texas for Kenaf International. In the 1994 growing season, more than 200 acres of kenaf seed production were located in the Lower Rio Grande Valley of Texas with a seed yield of over 700 pounds per acre. There is actually a surplus of seed available for the present market demand. However, an adequate supply of good quality seed is an important factor for the continued expanison of kenaf. The seed produced in Mexico has already increased the competition and lowered seed costs to many producers. Much of the seed in the past has been produced in the tropics of Central and South America and Mexico.
Variety Testing: Varieties of kenaf are being tested from California to Delaware. New varieties being developed by Dr. Charles Cook, USDA, are now being included in many of these trials. Many of these varieties are adapted to different types of soils. In California, excellent yields have been obtained on saline soils (Bhangoo and Cook, 1995). For many years it was thought that good yields could only be accomplished in the more coastal plains of the south. However, in 1965, Purdue University in Central Indiana tested some kenaf varieties and had dry matter yields of 10.9 tons per acre (Lessman, 1965). In 1966 a research report from Nebraska (Williams, 1966) indicated that yields of 3.7 tons/acre and 6.9 tons/acre were achieved without and with irrigation, respectively. This was with the variety Everglades 71 which is still being used today. Recent studies have shown that yields of 6 to 7 tons of dry matter per acre (DM/acre) are possible in many areas of the U.S. including Illinois, California, Louisiana, Mississippi, Kentucky and Texas. Satisfactory yields for economic production appear to be possible as far north as Central Illinois (Lambert et. al., 1995). The 1970 report mentioned earlier stated that “high yields have been obtained as far north as Indiana, Iowa, Kansas, and Nebraska.”
There are 2 distinct leaf shapes on the different kenaf varieties. Some varieties have deeply lobed leaves (usually called palmate) with mostly seven appendages on each leaf. Other varieties have shallowly lobed (usually called entire) leaves. These are much more desirable from the standpoint of law enforcement agencies involved in reducing marijuana production and the public because the palmate leaf is often mistaken for the marijuana leaf . During the 1994 growing season at Lexington, Kentucky, an anonymous caller claimed that the University of Kentucky was growing marijuana test plots at the research farm. The DEA investigated the claim and discovered kenaf test plots rather than marijuana. The Everglades-41 variety that was increased in 1994 has the entire leaf shape and should not be confused with the marijuana leaf. At the present time, the palmate leaf types appear to be more consistent in their yield potential and fiber qualities. However, new breeding is aimed at improving the entire leaf types for future use (Baldwin, 1994). As kenaf becomes more widely grown, I believe with good educational programs these differences will be quite evident.
Soil selection and moisture requirements: Optimum growing conditions for kenaf are: mean daytime temperatures of 73-8O° F, a mean night time temperature of 65-75° F and at least 150 frost free days. Kenaf requires about 3 to 5 inches of rainfall per month or 18 to 30 inches during the growing season. A survey of the southeastern states shows a rainfall total of 22 to 34 inches of rain in all of the states. The rainfall is adequate for good kenaf production except when severe droughts occur. Droughts are more common in the Carolinas and Georgia than any other states. It was reported that Kenaf has the capability of becoming somewhat dormant during a long dry spell and then exploding in growth when good raitifall occurs (Personal communication, Cook) With fair to adequate rainfall, it will continue to grow and not be affected by periods of lower rainfall as compared to corn or soybeans. The deep tap root system enables kenaf to survive better during stress periods. In 1994, just slightly over 17 inches of rainfall was recorded on the research station near Lexington, Kentucky where the first kenaf variety trail in Kentucky was being conducted. This test was on a well-drained Maury silt loam that is drought prone in dry weather. Kenaf did not shown any signs of stress from lack of moisture. Excellent growth occurred whereas corn in an adjoining filed suffered drought stress.
The growing season for the upper southeastern states is from May to October. The average rainfall in inches for these states is: Kentucky – 23, North Carolina – 24, Tennessee – 22, Virginia – 26, and West Virginia – 23.
The growing season for the lower southeastern states is from April to October. The average rainfall in inches for these states is: Alabama – 28, Arkansas – 29, Florida – 32, Georgia – 27, Louisiana – 31, Mississippi – 29, Oklahoma – 25, South Carolina – 30 and Texas – 34.
Seeding rate and row width: The best seeding rate is 80,000 to 110,000 plants per acre. This will be from 6 to 8 plants per foot of row in 20,30 or 36 inch row widths. This is from 6 to 10 pounds of seed per acre. There is disagreement in the literature and among researchers as to the best row width to use. The research in Mississippi (Hovermale, 1993, Neill and Kurtz, 1992) suggests that highest yields are obtained at 20 inch rows while in the Rio Grande area of Texas, Charles Cook states that he sees no difference in yield between 30 and 40 inch rows.