Hemp’s Enemy Weeds
by Sasha Przytyk, Gen-X Research

In general, there are few weeds that can persist in the dense shade of a good hemp crop. When its requirements are met, and it gets off to a good start, hemp grows rapidly and has been known to choke out most common weeds. This is due to the species’ fast vertical growth and impenetrable leaf canopy.

Hemp has often been recommended as a weed control crop; however, this is not necessarily the case. When a crop doesn’t get a good start for one reason or another, competition from common weeds like thistles, quackgrass, wild oats, mustard and lamb’s quarters can become a real issue. Poor drainage or lack of nutrients can slow the crop’s growth and make it more vulnerable to invading weeds. To take advantage of hemp’s competitiveness, care must be taken to sow at a high enough seeding rate, in fertile, well-drained soil, to achieve quick ground coverage. This is especially true with regards to shorter seed crops.

Good preparation of the seedbed is essential. Hemp is very responsive to an even, fine seedbed. Like most spring crops, it is negatively affected by compacted crusty soils, absence of rain, and/or lack of drainage. Mechanical weed control is necessary to eradicate early emerging weeds, especially in organic production. The land should be cultivated as early as possible, disked and harrowed. Thorough, deep plowing or cultivation gives the hemp the opportunity for the development of its root systems.

No herbicides are registered for use on hemp, although "Poast" and "Pardner" have been shown to work on grassy weeds without significantly damaging most varieties of hemp (Manitoba Agriculture 1999, University of Saskatchewan 1999). Although a pre-plant burn-off with "Roundup" may prove successful in controlling weeds in conventional farm programs, I will not personally advocate the use of unnecessary, harmful herbicides.

A hempseed crop should not follow a wheat crop, since volunteer (re-growth from unharvested seed) wheat can be a vector of sclerotinia (hemp canker), and small wheat grains are difficult to clean out from the hempseed. Neither should hemp be planted after a spice crop such as coriander. When these herbs re-grow amongst the hemp crop, their seeds are also difficult to separate from hempseeds, and impart their flavour to the hemp oil in the crushing process.

Wild buckwheat can be a major weed control problem, as the plant climbs up the stem and flowers at the same height as the hemp. Again, cleaning is challenging since wild buckwheat seeds are about the same size as small hemp seeds.


"Broomrape": For more info, visit: http://ext.agn.uiuc.edu/abstract/289.html or http://ext.agn.uiuc.edu/wssa/subpages/weed/WT72.htm

Less common, but more serious than wild buckwheat, are several noxious weeds: Broomrape is among the worst agricultural pests in many parts of the world. It is sometimes found where wormwood grows throughout the southern Canadian prairies, and is reportedly parasitic on hemp's roots.


"Bindweed" (Strangleweed, Wild Morning Glory, Creeping Jenny)
Photo credit: Wild Plants of the Canadian Prairies, A.C. Budd & K.C. Best, Canada Dept of Agriculture, 1964. For more info, visit: http://www.agf.gov.bc.ca/croplive/cropprot/weedguid/bindweed.htm

Also prohibited (in hempseed growing standards) are the bindweeds, members of the morning glory family, that climb up the hemp stems and produce white or pink funnel-like flowers; Field bindweed is sometimes confused with wild buckwheat. The two species are differentiated by leaf shape: wild buckwheat has a heart-shaped leaf while field bindweed has a spade-shaped leaf. Dodder, another climbing, parasitic weed found in the south-eastern prairies is very difficult to identify, but an enemy nonetheless.


"Dodder" (Beggarweed, Hellweed, Strangle Tare, Scaldweed, Devil's Guts)
For more info, visit: http://www.agf.gov.bc.ca/croplive/cropprot/dodder.htm

In growing hemp for seed, all weeds of these types should be avoided as they can be extremely damaging and may result in crops being downgraded or refused. If found, they should be reported to a local Ag. Canada representative. Although damage caused by these noxious weeds has not observed in modern-day Canadian hemp crops, they were reported in earlier hemp growing days, and cannot be discounted in these times of renewed growth.

Sasha Przytyk is the manager of Gen-X Research Inc.

For another article that deals with the herbicide control of volunteer hemp plants, check out www.gov.mb.ca/agriculture/news/topics/daa18d02.html

Hemp as Silage: Alberta Research Results
An Alberta Agriculture Study that looks at hemp's potential as a cattle feed has been released. Low THC Hemp (Cannabis sativa L.) Research Report 99-10028-R11999 - Hemaruka, Alberta, reports on a 1999 trial undertaken in Central Alberta to grow hemp as silage, and to feed the silage to back-ground heifers. The hemp fed heifers were compared with heifers fed a conventional diet of barley/oat silage.
Note: At present Health Canada will not grant a permit to grow hemp for silage. This work was done under a research permit.

The research was conducted by farmer/co-operator Ron Letniak of Consort Alberta, Cereal and Oilseed Specialist Curtis Weeks, Dr. Stan Blade, Director of Edmonton's Crop Development Centre North, and Agnes Whiting, Technical Field Crop Representative, UFA.

This trial shows that hemp can be used as cattle feed when fed as silage; it notes that hemp silage is unusual in that it produces high yield per acre, high protein levels and relatively high yields (in general, plants grown for animal feed usually have high yield and high energy and relatively low protein. Hemp is one of the few plants that has all three, and does not require a supplement, as does the barley/oats mix.) The cattle found the hemp silage very palatable and readily accepted it as feed.

The study concluded that there was no significant difference between yield of the hemp and barley/oat silage and there was also no significant difference between the weight gain of the two groups of heifers over a 110-day feeding period. The study notes that the current high cost of hempseed, license costs and THC tests are offset by the savings hemp silage provides from the additional protein in the feed.

If the results can be repeated and verified in 2000, hemp could become a new source of forage for cattle producers, the study suggests.

Peace River, Alberta: Rycroft Hemp Trials
Twelve varieties were evaluated for their performance in Northern Alberta's Peace Region in 1999. A small silage trial with 4 varieties and a date of seeding trial with 5 seeding dates was also grown.

Overall seed yields were quite low; lack of moisture late in the season, with large cracks developing in the plots over late summer, may have limited seed yields.

USO 31 was the variety with the highest seed yield at 285 lbs./ac, followed by USO 14 (263 lbs./ac), Fedora 19 (260 lbs./ac) and FIN 314 (255 lbs./ac). Kompolti provided the highest biomass yield by far at 11695 lbs./ac. High biomass strains included Uniko B, Fedrina 74, Felina 34 and Futura.

The silage trial resulted in protein levels of 20.6% for Fedora 19, 19.4% for Futura, 20.9% for Uniko B and 21.0% for Zolo 13 when cut at 50 days after seeding. Hemp biomass yield was highest at the second cutting (75 days after seeding) for 3 of the 4 varieties. Biomass yield was slightly higher for the other variety at the third cutting (114 days).

Results of the date of seeding experiment revealed significant varietal differences between date of seeding and seed and biomass yields. There was a trend to higher yields with earlier seeding dates in all varieties.

All of the varieties involved in the trial tested 0.15 % THC or less, with several, including Fedora 19, Ferimon, the USO's and Zolo 11 testing under 0.05%.

Complete details can be found at http://www.agric.gov.ab.ca/offices/fairvreg/agfarm/fff_spcrops.html

Hemp Farmer Makeover
By Arthur Hanks & Dr. Alexander Sumach; thanks to David Marcus and Jerzy Przytyk

Canada's new crop or special crops industry has seen substantial growth over the past decade, expanding from just over 2 million acres to 5.3 million acres in 1999. Agriculture Canada forecasts a 10% increase in special crop acres this spring to 6.8 million acres, as farmer's switch from canola to crops with better returns. These crops include legumes such as dry peas, chickpeas and lentils; canary seeds, mustard seeds, buckwheat; spices and herbs. Many of these crops, importantly, are GMO-free.

Ag Canada also forecasts that crops such as spelt, kamut and quinoa have good market potential. Industrial hemp is another crop in Canada's agricultural mix that is rated as having good potential.

How long can you eat on potential? Over the past two years, the country's fledgling hemp industry has had to identify and create markets, deal with the financial uncertainty of a few companies who have set up shop, and handle a difficult border situation with Canada's largest trading partner.

In this context, a large number of farmers, by choice or by necessity, have had to seek their fortunes with hemp on the open market.

Below is an email, which the HCFR's editorial team received from a farmer in mid-April. He grew hemp on speculation for the past two years and has been frustrated with the slow pace of market development. His situation is representative of many producers out there.

The HCFR contacted two consultants who are knowledgeable about the state of hemp markets --- David Marcus of Toronto's Natural Hemphasis, and Jerzy Przytyk of Quebec's Hempco --- for advice on how this anonymous farmer should proceed.

source: Alberta Agriculture

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Hemp Farmer: Thanks for getting back to me about hemp and associated products.

When you asked for a price I must confess that I am not up to a product list but would like to sell some of the last two years worth of seed to purchase this years acreage. If I do not sell any of last year's seed then I will only plant the minimum acreage (10) if seed sells I have left open 35 and possible 75 acres.

The seed I have from last year is Felina 34. This has real good GLA's and the THC levels are real low (I think it was about 0.1% during the growing season). I have 8000 lbs.

My seed was not been forced dry with heat instead it was slow dried in ventilated wagons and took close to 2 months to reach a good storage level. It is packed in large shipping totes that range from 1400-1600 pounds and I can arrange to deliver with my own truck if the haul is not too far.

The seed I have from 2 years ago is Irene and in most cases it will test with some THC in the oil but Kenex did some sampling and said it was close but not a real problem. There is close to 9000 pounds.

The seed is clean and has no white or immature seed very few cracks.

When it comes to fibre I have close to 500 4x4 bales and they average 400 lbs. Some of the fibre is cut at the perfect stage for fibre; some is after the seed was removed. None of this fibre has the tops of the plant in it. Then some of that has been left out to ret for the winter --- this removes the pectin and makes it very soft but it will cut down the fibre strength if allowed to touch the ground or get bleached by the sun for too long.

I would like the seed to bring me $1.00 a pound or I could set a better price for the whole lot?

Thanks for listening to me and I hope we can make a difference.

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David Marcus: Obviously growing on spec is not the way to go at this point. Unless as a farmer you are contracted (by a 'reputable' firm), chances are you shouldn't be growing. If you really want to be involved in developing the industry, then your focus should be on product development and taking the product to market. This value-added approach will result in smaller acreages being more profitable. In this way, farmers can tackle local market first and if the demand exists, grow from there.

So, yes, I think your farmer has the right idea. As far as product development for others, there's probably no need at this point to grow in the first place as there is ample supply on the market at a price that will be very competitive for what you could grow it for yourself (certainly in your first year of growing). Moreover the seed can already be bought in a processed form (i.e. dehulled) which eliminates the requirements to get THC testing, licenses and the rest (cost and time prohibitive). Most importantly, however, you don't have to forecast your demand, you can buy what you need when you need it.

If you are a contracted farmer, the key now is management practices to get yields up, and thus revenues. The contracting price of seed is already showing signs of sliding (necessary from an industry perspective to make hemp grain and derivative products more affordable), so higher yields are a must. The good news is that yields in many areas of the country have already shown to be very promising.

Jerzy Przytyk: It is quite a task to advise farmers about the marketability of their hemp grain. Especially now, when the North American hemp world is swimming in a sea of grain. In my part of the country, that is, in Quebec, your average organic farmer manages a mixed production. This includes, in most cases, livestock: dairy, beef, pork, chickens or some other beasts or birds. The goal of this type of organic farm is to achieve a "closed system" where all of the inputs are farm produced: compost for the fields and/or feed for livestock. If there is a market for hemp grain produced on this type of operation, great. If not, then the grain can be consumed by farm animals.

Taking into account the feed value of hemp grain, it is not hard to see that it can replace many animal ration components. Soy or flax can be replaced by hemp grain and in many cases will make a superior feed. The worth of hemp growing will be realised not only by the value of hemp grain but also by its value as a soil conditioner, as a weed suppressant and as a very excellent part of the crop rotation.

All this will make sense only if the gate price for hemp grain will be +/- $ 0.50/lb for organic grain and somewhere around $ 0.35-0.40/lb for conventional. Are these prices realistic? I think so. As much as I don't want to commodify hemp, the present price that the "generic" farmer demands for hemp grain is much too high. Once we take out the sexiness of hemp the real value of hemp grain is somewhere between soya and flax. Let's be realistic here. Why would consumers pay double for hemp oil when a well made blend of other oils can offer a nutritional value that is the same or superior to hemp¹s

Example: flax/borage or other oil blends. If hemp production requires less inputs and hemp has higher yields then flax why are we asking for such a high price?

Are we using the wrong varieties for grain production? Do we, as farmers have the right to demand high prices because of our own incompetency? We are in the beginning of the third year of hemp growing in Canada. It is time to get off this "disorient express" and look at hemp production as a part of our farming system and not as the magic bullet that will make farming a piece of cake.

1999 Comparison of Industrial Hemp Grain composition for oil, protein, fibre, essential amino acids and fatty acids from across Northern Ontario
By Gordon Scheifele, Northwestern Ontario Research Co-ordinator Kemptville College/University of Guelph, Thunder Bay, Ontario, Canada.

The future development of markets and industry for industrial hemp grain grown in northern Ontario is directly dependent not only upon the potential to produce the grain as an economically viable grain crop but also to demonstrate a consistent competitive quality of the industrial hemp grain for the pharmaceutical and nutritional industry. The performance of varieties, effects of agronomic practices, such as nitrogen fertility rates, time of seeding and harvest, location and year on industrial grain composition need to be established. The 1999 Northern Ontario Industrial Hemp research project was the largest and most comprehensive in Canada. It consisted of agronomic evaluations of variety performance for grain production, effect of nitrogen fertility, time of seeding and harvest on yield and grain composition for oil, protein and fibre, essential amino acid composition in industrial hempseed meal and essential fatty acid composition in industrial hemp oil.

Northern Ontario Hempfield, 1999 (G. Scheifele)

Summary: A total of five Industrial hemp research licenses and two commercial cultivation licenses were obtained from Health Canada to authorise legal permission to grow industrial hemp for grain production in Canada by the author and two commercial growers. Eight industrial hemp varieties (Fedora 19, Fedrina 74, Felina 34, Fasamo, Ferimon, Zolo 11, Zolo 13 and FIN 314) were evaluated for grain production across northern Ontario from Dryden to Verner (about 2000 km East to West ) and from 46^th to the 49.5^th latitude. A similar, but larger research project was conducted across northern Ontario in 1998 and data from this project is compared to that of 1999.

The composition of industrial hemp grain for oil, protein and fibre, industrial hemp seed meal for 18 essential amino acids (EAA) and oil for 12 essential fatty acids (EFA) was determined from clean grain samples at 4% moisture in 1999 and 12% moisture in 1998. All comparison of values from 1998 and 1999 were corrected to zero percent moisture.

Fedora 19 was consistently higher for oil composition in 1999 (mean of 34.1%) and in 1998 (mean of 31.7%). Thunder Bay had significantly higher oil composition levels (6% higher) in 1999 (location mean 33.8%) compared to the second highest location, Emo Agricultural Research Station (EARS) (location mean 31.9%). Kapuskasing Agricultural Research Station (KARS) was the lowest (location mean 30.9%). The 1999 northern Ontario oil composition for industrial hemp grain was 8% higher (environmental mean 32.9%) compared to 1998 (environmental mean 30.4%).

The 1999 protein composition of industrial hemp grain was inversely related to the oil composition. Ferimon had the highest protein composition levels (34.7%) compared to Fedora 19, which was the lowest (31.8%). The 1998 protein composition for industrial hemp grain was higher (environmental mean 39.4%) compared to 1999 (environmental 34.5%).

A regression analysis demonstrated the 1998 and 1999 interaction and differences for the industrial hemp grain oil and protein composition relationship. The 1998 oil and protein values were 31.6% and 39.3% respectively (for 51 comparisons) with a positive slope of +0.2 and a very weak correlation of 14%. The 1999 oil and protein values were 32.4% and 34.4% respectively with a negative slope of –1.03 and a relatively strong correlation of 79%.

Hemp Harvest, Northern Ontario, 1999 (G. Scheifele)

The oil composition of Fedora 19 at KARS did not increase as grain ripened (delayed harvesting), however the protein and fibre levels did decrease as the grain ripened. Delayed seeding from May 29 to June 18 resulted in a decreased grain oil composition by 7.1%. Protein and fibre levels increased as seeding dates were delayed. The effect of different levels of nitrogen (80-120 kg/ha) on Fedora 19 did not impact oil, protein or fibre composition levels in the industrial hemp grain.

The EAA composition of industrial hemp meal demonstrated variations within varieties and across locations. There were no consistent trends for any of the 18 EAA measured. Fedora 19 and Fasamo were the most and second most consistent varieties respectively for all 18 EAA across all environments (31). The effect of nitrogen levels, seeding and harvesting dates demonstrated variations in EAA levels. The increase of nitrogen rates from 80 to 120 kg/ha increased the following amino acids: GLU, ILE and TYR by 8, 14 and 30% respectively from the lowest to the highest rates. SER, PRO, VAL, PHE, HIS and ARG were decreased by 20, 15, 8, 16, 7 and 12% respectively from the lowest to the highest rate. The remaining amino acids showed no significant trend in change due to the increased rates of nitrogen.

The effect of time of harvest based on the maturity of the grain from 70 to 100% brown seed shows GLU, ALA and LEU increase by 10, 11 and 6% respectively. PRO, VAL and HIS decreased by 43, 25 and 10% as the grain was harvested at more mature stages. The remaining amino acids showed no significant trend in change due to the delay in harvest time producing more ripe grain.

The effect of seeding dates (May 29, June 4, June 14 and June 18) on the amino acids shows ASP, GLU, PRO, TYR and HIS increase by 16, 4, 17, 13 and 5 as seeding was delayed. MET, ILE, LEU and PHE decreased by 18, 21, 5 and 13 as the seeding was delayed. The remaining amino acids showed no significant trend in change due to the delay in seeding time.

There were variations in EAA levels between 1999 and 1998, however no specific trends could be detected.

The EFA composition of industrial hemp oil demonstrated variations within varieties and across locations for the 12 EFA measured. The EFA variability for each variety over the different locations was very slight. Compared to the variety environmental means: Fedrina 74 had 4% lower oleic acid at EARS; Ferimon had 18% less stearidonic acid at VARS; Zolo 13 was 4% lower for alpha linolenic acid at KARS; Zolo 11 was 3% lower for alpha linolenic acid at Verner Agricultural Research Station (VARS). FIN 314 was 7% lower for oleic acid at KARS and Fedora 19 was 2.3% lower for alpha linolenic acid at Thunder Bay.

The variety means were compared to the environmental mean. Only oleic acid was 3% higher than the environmental mean for Fedrina 74 and alpha linolenic acid was 2.7% higher for Felina 34. Stearic acid was 7.7% higher than the environmental mean for Ferimon, Fasamo and FIN 314. Arachidic acid was 12.5% higher than the environmental mean for Zolo 13 and FIN 314. Behenic acid was 33% higher than the environmental mean for Felina 34, Zolo 13 and FIN 314.

The VARS had 10 and Thunder Bay and KARS had 9 of the 12 EFA greater than the Environmental Mean. Emo Agricultural Research Station, Dryden and New Liskeard Agricultural Research Station had 8, 6 and 6 respectively of the 12 EFA greater than the Environmental Mean.

The increased rates of nitrogen from 80 to 120 kg/ha effected an increase of alpha linolenic (omega 3), gamma linolenic (GLA) and stearidonic acids, by 10%, 16% and 43%. Oleic and linoleic (omega 6) were decreased by 10 and 1.1%.

The effect of delayed harvest (increased ripening of the grain) resulted in a 4% decrease in stearic acid and a 1% increase in linoleic acid.

The delay in seeding from May 29 to June 18 resulted in the decrease of palmitic and alpha linolenic acids by 3 and 2%. The Stearic, oleic and linoleic acids were increased by 12, 2 and 1%.

FIN 314 was the only variety with a significant variation for gamma linolenic (GLA) and stearidonic acids comparing 1998 to 1999. In 1998 it was 4.22, 69.5% and 1.53, 64.5% higher respectively than the environmental mean (2 locations in Thunder Bay). In 1999 gamma linolenic and stearidonic acids dropped to 2.4 and 0.8 respectively, 4.3% higher and 20% less respectively than the environmental mean (2 locations, KARS and Thunder Bay).

The EFA composition profiles for industrial hemp oil from northern Ontario grown industrial hemp grain were significantly higher for palmitoleic, stearic, oleic, linoleic, stearidonic, arachidic, behenic and lignoceric acids (8 out of 12) to those published for industrial hemp grain produced outside northern Ontario (Crew 2000, Hempola). The EFA profile for all the varieties examined across all of northern Ontario was almost a precise 3:1 ratio of linoleic (omega 6) to alpha linolenic (omega 3) acids for 1998 and 1999. The 1998/1999 FA profile was: percent saturated fatty acids = 10.09% (palmitic, stearic, arachidic, behenic and lignoceric); percent monounsaturated fatty acids = 12.42% (palmitoleic and oleic); percent polyunsaturated patty acids = 77.08% (linoleic, gamma linolenic, alpha linolenic and stearidonic).

These impressive profiles of industrial hemp grain for composition of oil, protein and fibre, and the industrial hemp seed meal for EAA and oil for EFA is important for the future development of markets and industry for industrial hemp grain grown in northern Ontario. The northern Ontario-produced industrial hemp grain is competitive with grain produced in other regions to meet the requirements of pharmaceutical and nutritional interests in oils high in EFA, especially the omega 6 and 3 in the ratio of 3:1 for human health requirements.

Continued research is essential to establish the significance of year to year effect on industrial hemp grain composition for oil, EAA of industrial hemp seed meal, EFA of the oil, the agronomic management practices of fertility, time of seeding, harvesting and variety.

For more information on the 1999 Comparison of Industrial Hemp Grain Composition contact Gordon Scheifele at: gscheife@omafra.gov.on.ca

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