1995 Hemp
Trials in Manitoba, Canada
1995 Hemp
Trials in Manitoba, Canada
Courtesy of Jack Moes, P.Ag. - New Crops Agronomist
HEMP - March 1996 Update on Manitoba Experience and Future prospects
Jack Moes, P. Ag. - New Crops Agronomist
Soils and Crops BranchQuick Links to sections:
HEMP - Update on Manitoba Experience 1995:
Hemp Quick Facts
Current Status.
Commercial cultivation was illegal in Canada until 1998. Cultivation for research purposes up to 1998 was possible under license granted by Health Canada.Possible Uses.
fiber. Apparel textiles, industrial textiles, cordage, pulp/paper, building materials, fiber-reinforced plastics.
Seed. Edible oil products, cosmetics, protein products.Characteristics.
Hemp (Cannabis sativa L.) is a tall growing annual species, maturing to seed in 110- 150 days depending on variety. Varieties can be either dioecious (separate male and female plants) or monoecious (male/female flowers on the same plant). Stem has an outer “bark” which contains long bast fibers.Growing the Crop.
Varieties. Most currently available industrial hemp varieties from Eastern Europe or France.Seeding. In Manitoba, hemp could be sown by mid- May, using conventional seeding equipment. Grown for fiber or seed, the seeding rates would be about 400 to 100 seeds/square metre, respectively.
Fertilizer. Information is scarce, but good results obtained by fertilizing as for a high-yielding wheat crop. Maximum levels with seed not known.
Weed Management. Herbicide screening has not yet been done. A uniform stand that emerges ahead of weeds will be very competitive.
Diseases. Sclerotinia sclerotiorum and Botrytis cinerea can be significant.
Insects. Bertha armyworm (Mamestra configurata) will be a significant pest.
Harvesting. Highest quality fiber obtained by cutting at early flowering. Mower/conditioner and round-baler may be suitable for low to medium quality end uses. Best approach for harvesting appears to be direct combining when shelling becomes evident.
Marketing. No established marketing channels, value in market place is uncertain.
Introduction
Hemp is a crop that has captured plenty of attention and imagination. Some unabashedly promote hemp as a wonder crop that can save us from all of our economic and environmental problems. But unlike other crops we might consider, this one is actually illegal - it can only be grown under a research license granted by the Health Canada's Bureau of Drug Surveillance. Hemp is Cannabis sativa, the same species as marijuana, but the narcotic component is very low. The question is: is there something of a real opportunity in hemp?
Hemp is naturally a dioecious species - this means that male flowers (the pollen source), and female flowers (where the seeds set) are borne on separate plants. Once the males have done their work (shedding pollen), they die. After this, the males and females become quite different in the quality of their fiber, which is undesirable for higher-end fiber uses like textiles. To overcome this some of the European hemp varieties have been bred to be monoecious - still separate male and female flowers, but on the same plant.
What is the main claim to fame of the hemp plant? The stem in cross-section shows a green "bark" containing very long, strong fibers. These are the bast fibers that have been used for centuries to make clothing, rope, twine, and paper. The whitish core, called "hurds", is very light and corky, but contains some very short fibers which are still useful in pulping or in building materials. The hurds are very absorbent, and are the basis of about 2,000 acres of commercial hemp production in the U.K. by a company which sells the hurds as horse bedding.
A process called retting dissolves the non-fiber portion of the bark, and is necessary for extraction of the highest quality fibers. Traditionally, retting was accomplished by letting the stalks lay in the field for several weeks prior to bundling them up, or by soaking bundled hemp stalks in ponds. After retting, the stalks are mechanically decorticated - ie. the long fibers are separated from the hurds. Without retting, decortication will result in fiber with a relatively high hurd content, which is suitable for applications not requiring the highest quality fiber.
Hemp seed is a good source of oil that has been used historically for applications like paints and varnishes, as well as for edible purposes.
Currently, there is much interest in the diverse applications of industrial hemp - not only some of the traditional uses in clothing, cordage, pulp & paper, but some new ones including industrial textile products, natural- (vs. glass-) fiber reinforced resins, composite building materials, and hemp-oil based cosmetics.
It is illegal to cultivate hemp, except under research permits granted by the Federal Department of Health. Hemp cultivation has been illegal since 1938, when it was banned under federal narcotics regulations. Hemp falls under these regulations because it is Cannabis sativa, the same species as marijuana. Hemp has the same narcotic component delta-9-tetrahydracannabinol (THC) as marijuana, but at very low levels - commercial hemp must be less than 0.3% THC, while marijuana will have at least 10 times higher levels.
In the 1920's, Agriculture Canada was involved in hemp research, as part of their fiber crops program which focused mainly on fiber flax. There was some commercial acreage at that time, rising to a peak of over 1000 acres in the Portage area in 1928. By the time the crop was banned in 1938, acreage had declined to zero due to economic factors.
1995 Manitoba Trials
Four trials were conducted with these objectives:
- evaluate hemp cultivars for adaptation and quality
- observe for agronomic problems
- evaluate seeding/harvest with available equipment
- estimate economic potential.
Two of these trials were replicated small-scale cultivar evaluations. The other two were larger scale plantings of approximately 5 acres each.
Agronomic Problems
Experience this year pointed out that hemp is not quite the problem-free crop that some have suggested. A hemp crop is expected to do a good job of suppressing weeds. The competitive edge is based on a uniform crop stand that emerges ahead of weeds and has the early advantage. One of our hemp trials suffered from delayed and non-uniform emergence due to a dry seedbed - the weeds got the advantage and the plot was ultimately worked down.
Some have suggested that nothing eats hemp. We found that deer like to nip off the tender growing points, but they leave the tougher fibrous parts alone. Lygus plant bug feeding was observed, but these caused only very minor damage, and probably will not be more than an incidental feeder. Bertha armyworm (Mamestra configurata) loves hemp leaves. They were capable of reducing a plant to nothing but a stalk with a few leaf skeletons - some salvageable fiber, but no further yield. Bertha is a periodic pest in Manitoba, and after the next year or two is not likely to be much trouble for another 10 or 15 years or so - but when we are in an armyworm cycle, this will be a pest of major consequence.
Some also suggest that hemp is free of diseases. However, hemp is quite susceptible to sclerotinia (Sclerotinia sclerotiorum). It came in the form of stem lesions that killed off the upper part of the plant and left the plant very prone to lodging. Other sclerotinia-susceptible crops include canola, sunflower, field beans, peas, and lentils - another management consideration for prospective growers.
The Prairies are well known for high-wind and heavy-rainfall events - the tall plants with these leafy inflorescences catch the wind and are quite susceptible to lodging. The lodging was worse with Sclerotinia infections, but even where there was no disease, lodging with stem kinking and breakage still happened.
There will also be logistical questions of harvesting these tough plants that are often more than 8 feet tall. It will take some specialized and very sturdy equipment to do this on a field scale. If seed production is the goal, the challenge will be to harvest seed from the top of an 8 foot tall plant, without plugging the combine or destroying the fiber which will still be useful for low-quality purposes? These are not insurmountable problems, but are challenges to be faced if actual commercial production becomes possible.
Yield, Maturity, and Delta 9 - THC Content
By the time the necessary permits were in hand and the seed was imported, it was early June - 3 to 4 weeks after the ideal seeding date. The varieties ranged in flowering date and maturity (Table 1) - Zolotonosha 11 and 13 set mature seed even with the late seeding, Beniko and Bialobrezeski were intermediate and probably would have matured with timely seeding, and Uniko B and Kompolti appeared to be too late to set mature seed in our growing season.
Stalk yields were in proportion to maturity - the longer the vegetative growth period (ie. prior to flowering), the higher the yield (stalk yields were determined at mid-flowering). Stalk yields were a bit low compared with European results of 7,000 - 15,000 kg/ha, but encouraging given this as our first experience. Stalk fiber quantity and quality have not yet been determined.
THC content was determined at mid-flowering. Several varieties produced THC in excess of our licensing requirement of 0.3% (data not provided). According to licensing requirements, all material of these varieties was destroyed. Since the pedigree of these varieties cannot be verified, no conclusion can be drawn about whether or not THC levels in these varieties will be consistently high. Pedigree-verified seed will be secured for future studies.
Seed yields were determined for the two early maturing varieties (Table 1). These yields were well below the expected range of 500-1000 kg/ha, likely due to the late seeding and the high seeding density used for the trials. (Seeding density was 300 seeds/m2 - suitable for fiber production but about three times what is considered in Europe to be suitable for seed production.)
Seed Oil Quality
Tables 2 and 3 provide information on the seed oil of Zolotonosha 11, with samples coming from two sites in Manitoba and from our original seed supply. Data for Zolotonosha 13 was obtained, but was similar and is not included. Some data for canola is included for reference. This preliminary data suggest that hemp seed has potential as a relatively valuable specialty oil, primarily from a nutritional perspective, but also from an industrial perspective. In particular the good balance of desirable fatty acids and anti-oxidants in hemp oil suggest it is potentially high-value specialty oil.
Fatty Acids.
Both gamma-linolenic acid (18:3n6) (GLA) and alpha-linolenic (18:3n3) (LA) are regarded as nutritionally very valuable. Ordinarily, vegetable oils are a poor source of GLA; the 2 - 3% found in the hemp seed (Table 2) is relatively high for a vegetable oil. The high LA is attractive from a nutritional perspective, but oils with high LA can be unstable - this requires processing and packaging techniques designed to increase the stability (ie. shelf life) of the oil. However, the hemp oil is also rich in tocopherols, natural antioxidants which can protect the oil from what would otherwise be a tendency to go rancid relatively quickly (see next paragraph). LA also imparts a fast-drying character to the oil, making the oil useful for lower value applications such as printing inks and paints.
Tocopherols.
The tocopherols and tocotrienol are natural antioxidants (tocopherol is Vitamin E). While that fact that this serves to protect the oil against spoilage is important, the fact that hemp seed oil appears to be a relatively good source of these antioxidants (Table 3) makes the oil of interest from a nutritional perspective (antioxidants currently are the subject of much positive nutritional discussion). The g-tocopherol and a-tocotrienol are particularly active as antioxidants.
Sterols.
Sterol composition of this hemp seed oil (data not shown) is typical for plant oils, but in the high end of the normal range. Sterols are of interest in oils because plant sterols block absorption of cholesterol. If an oil is rich enough in sterols, the extraction of sterols as a separate pharmaceutical component could be of value.
Key Elements in New Crop Success
Successful new crop introduction depends on profit for growers, which depends both on low-cost production and a high enough market return. In the case of hemp, there is also the barrier of federal regulations.
On the basis of 1995 experience, hemp production appears feasible from an agronomic perspective. Varieties are available which are adapted to our environment and have the potential for acceptable yields of stalk and seed. Production challenges will include disease, insect and weed management, lodging and harvest technology. While we have no information yet about the quality of fiber produced in 1995, the seed oil analyses suggest some interesting characteristics which could be marketable.
Is industrial hemp a potentially profitable crop for Manitoba farmers and processors? Potential appears to be there, but much is not yet clear. Here's some of what we need to know yet:
- actual value of seed, stalk, fiber, hurd;
- actual potential of marketplace to grow;
- production/regulation scenarios
We plan to continue trials in the 1996 season.
For 1996, commercial hemp production is not possible. With continued favorable research results and industry interest, commercial production may become feasible within several years. If commercial production does become legal, we can expect that it will be under some kind of regulatory/licensing mechanism because of the species.
+ The seed of these varieties was not received from the originator of the variety. Therefore, the pedigree of the varieties as tested cannot be verified absolutely. The performance as tested may or may not reflect performance if actual pedigree-verified seed had been used - thus variety specific results should be viewed with caution.
FOR FURTHER INFORMATION:
Jack Moes, P.Ag.
New Crops Agronomist
Manitoba Agriculture
1129 Queens Avenue
Brandon MB R7A 1L9Phone: (204) 726-6383
Fax: (204) 726-6260
ACKNOWLEDGMENTS
Funding for seed and laboratory analyses was supplied by Sustainable Development Innovation Fund. Our farmer and processor cooperators cannot be identified at this time, but their contributions are gratefully acknowledged.
Do you know more about this? E-mail us at Matthew@HempWorld.com
*Industrial-Hemp has no psychoactive properties following definition of the European Economic Community (EEC); THC content is less than 0.3%. In general, low THC-seed varieties without psychoactive properties are those that have a THC content of less than 1%. (See also No-THC Hemp-seed.) THC= Delta-9 TetraHydroCannabinol.
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