1996 Hemp Trial in Manitoba, Canada

Courtesy of Jack Moes, P. Ag. - New Crops Agronomist

HEMP - May 1997 Update on Manitoba Experience and Future prospects
Jack Moes, P. Ag. - New Crops Agronomist
Soils and Crops Branch

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HEMP - Update on Manitoba Experience 1996:
Following up on our initial experience in 1995, further hemp trials were conducted in 1996 in Manitoba. These studies had the following objectives:

v continue evaluating varieties of hemp for their agronomic suitability for production in Manitoba (after 1995 studies)

v providing initial indication of tolerance of hemp to herbicides and seed-placed fertilizers

v evaluate seed yield in small-plot and large-scale (> 1 acre) trials, with hemp grown at approximately ¼ of fiber seeding rate

v evaluate quality of seed and fiber for various potential uses

v observe for potential disease, insect or other agronomic problems

v estimate economic feasibility of hemp production in Manitoba, at farm-gate level

Trials took place at five locations - three were variety evaluation experiments and two were evaluations of grain production (hemp seed for industrial / edible utilization) on field scale (1.5 acres each under conventional and organic management). The experience gained from these trials is summarized under the following headings:

® Phytopathology of Seed

® Field Trials - Grain Hemp

® Small-plot Variety Evaluation - Fiber

® Small-plot Variety Evaluation - Seed

® Herbicide and Seed-placed Fertilizer

® Insect Survey

® Pollinators Associated with Hemp

® Fiber Quality Evaluation - Pulp

® Seed Oil Quality Evaluation

® Economic Analysis

Phytopathology of Seed

In addition to import permits from Health Canada, import of seed also requires an Agriculture Canada Seed Import Permit. For import of Cannabis hemp seed, directive D-96-03 of Agriculture and Agri-Food Canada, Food Production and Inspection Branch, Plant Protection Division requires a specific declaration of freedom from the following quarantine organisms:

v Pseudomonas syringae pv. cannabina (bacteriosis of hemp)

v Xanthomonas campestris pv. cannabis (leaf spot of hemp)

v Fusarium oxysporum f. sp. cannabis

v Pseudoperonospora cannabina (downy mildew of hemp)

v Orobanche spp. (Broomrape)

While our imported seed was found free of the quarantine organisms, the following list of organisms was found to be present in some or all of the samples:

v insect parts indicative of poor seed cleaning

v numerous fungal isolates including significant quantities of sclerotinia sclerotirum; latter indicative of poor seed cleaning

v seeds of other plant species including barley, wheat, sorghum, beet, and oat; again indicative of poor of poor cleaning

Proper seed cleaning, prior to importation if possible, is needed to optimize performance of these varieties. Infrastructure and expertise to accomplish this to the standards expected in our seed industry may be lacking in the countries of origin.

Field-scale Trials - Grain Hemp

Certified Organic†

Key Observations:

v A good stand is crucial to the ability of hemp to compete with weeds, especially with the low seeding rate (100 seeds/sq.m) used for grain hemp production. In areas where stand was poor (sown too shallow for moisture conditions or excessive moisture in low areas of field), competition from weeds was severe (no quantitative estimate was made).

v Particular weeds may cause more than just competitive loss. Wild mustard (Sinapis arvensis) infected with Sclerotinia sclerotiorum provided the source of stem rot lesions on adjacent hemp plants. These lesions caused wilting and death of the upper portion of the plant and rendered the plant more susceptible to lodging due to stem breakage; well-developed sclerotia approximately 3 mm in diameter were evident in the hollow of affected stalks by approximately early September when the lesions were first evident early in August. In the most severely affected area of the field as many as 50% of the plants were affected; however, overall approximately 25% of the plants were affected.

v Hemp plants in a low area of the field (poor drainage) were yellowed, stunted, and variable in height, suggesting that hemp ideally requires a more loamy soil with good internal drainage. Heavy or otherwise poorly drained soils will likely lead to poor performance.

v Direct combining worked well, provided the combine header was operated at approximately 36 - 48 inches above the ground, to minimize the amount of non-seed bearing stalk passing through the combine.

Total seed yield from approximately 1½ acres was approximately 400 lbs.

v Post-harvest seed evaluation has not yet been completed. While the seed yield was not exceptional, it was reasonable considering the stand, weed pressure, and disease. This trial points to the need to ensure the establishment of a uniform, vigorous stand of hemp, to learn to manage weed so as to reduce competitive effects and possible disease hosts, and to select a growing location with soil that has good internal drainage.

† Note that although the harvested hemp seed would qualify as Certified Organic, having been grown on eligible land, it was not inspected and documented in compliance with requirements for certification. Note further that the "organic" and "conventional" fields differed only in the status of the land (ie. eligibility for organic certification) and in the type of fertilizer used — no pesticides were used in either case.

Conventional

Key Observations:

v Comments as above with respect to stand establishment, weed competition, and direct combining apply here as well

v Some plants were affected by Sclerotinia sclerotiorum and the source of infection appeared to be volunteer canola plants from a canola crop grown two years previous. Approximately 1 - 2% of plants were affected.

v Seed harvested was approximately 400 lbs from 1½ acres.

Additional comments as above under organic.

Small-plot Variety Trials - Fiber

Site 1 - Southwest Manitoba - The first five varieties listed (Table 1) were similar in flowering date and were cut for evaluation on August 7 (57 days after sowing). The next four varieties were later to flower and were all cut on August 15 (65 days after sowing). In general, the later flowering varieties were taller and yielded considerably higher, since they had an extra eight days of growth. If high quality fiber production is the objective, clearly the late varieties are preferred from a productivity perspective. However, the issue of relative fiber quality among these varieties has yet to be explored. These varieties did not differ significantly in stand count, with an average 30% of the seeds resulting in a harvestable plant (500 seeds/sq.m. ® 149 plants/sq.m. at harvest). Further trials are necessary to determine optimum seeding rate for fiber production in Manitoba. All varieties were sampled at early flowering to determine Δ9 - THC content; all tested below the maximum allowable level of 0.30%, except Uniko B which tested at 0.30%.

Site 2 - Central Manitoba - Comments are similar as at Wawanesa, except that plant stands differ by variety (Table 2). In general, Fedora 19, Feline 34, and Kompolti seem to exhibit greater seedling vigour than other varieties tested, with up to 80% of the seeds producing established seedling. The apparent discrepancy in average stand density between Morden and Wawanesa may be due to the time the counts were taken (seedling stage at Morden, pre-harvest at Wawanesa). The lower counts at Wawanesa possibly reflect stand self-thinning as documented by VenderWerf in the Netherlands.

Site 3 - No useable data were taken.

Table 1 - Agronomic characteristics and Δ9 - THC content for hemp cultivars grown at fiber density (500 seeds/sq.m.) - 1996 Southwest Manitoba.

Cultivar

Stand

(plants/m2)

Height

(m)

Stalk Yield

Δ9 - THC

(%)

(kg/ha)

(lb/acre)

Zolotonosha 11

158

2.11 c†

7860 bc

7020 bc

<0.05

Zolotonosha 13

145

2.12 bc

7920 bc

7070 bc

<0.05

Polish 1

142

2.07 c

8150 bc

7280 bc

0.13

Polish 2

114

2.07 c

7260 c

6480 c

0.17

Fedora 19

164

2.08 c

8440 b

7530 b

0.10

Felina 34

185

2.19 b

10710 a

9560 a

0.06

Uniko B

119

2.35 a

10520 a

9390 a

0.30

Kompolti

139

2.33 a

10450 a

9330 a

0.21

Futura 77

172

2.31 a

11160 a

9960 a

0.15

LSD (0.05)

NS

0.08

1070

960

  

Average

149

2.18

9160

8180

  

CV (%)

21.5

2.6

7.2

7.2

  

† Values within a column are significantly different if not followed by the same letter.

Table 2 - Agronomic characteristics and Δ9 - THC content for hemp cultivars grown at fiber density (500 seeds/sq.m.) - 1996 Central Manitoba.

Cultivar

Stand

(plants/m2)

Days to Flower

Height at Flowering

(cm)

Stalk Yield

(kg/ha)

Δ9 - THC

(%)

Zolotonosha 11

245 c†

52 bc

218 b

5160 b

<0.05

Zolotonosha 13

230 cd

51 c

230 bc

4540 b

<0.05

Polish 1

210 cd

52 b

227 bc

5200 b

0.06

Polish 2

179 d

52 bc

223 c

4400 b

<0.05

Fedora 19

415 a

53 b

220 c

4890 b

0.08

Felina 34

370 ab

60 a

237 b

7290 a

0.07

Kompolti

331 b

60 a

252 a

7200 a

0.18

Futura 77

263 c

59 a

248 a

7330 a

0.06

LSD (0.05)

66

2

11

1110

  

Average

280

55

232

5750

  

CV (%)

16.4

2.3

3.4

13.4

  

† Values within a column are significantly different if not followed by the same letter.

Small Plot Variety Evaluation - Seed Trials

Low-key market and economic feasibility studies suggest that growing hemp as an oilseed crop may have significant potential for Manitoba. Therefore, we conducted variety trials aimed specifically at evaluating several varieties for their seed production. Note that these varieties have been bred as fiber producers and are not particularly prolific seed producers. However, varieties bred as seed producers are not readily available. To promote branching, flowering and seed set on these fiber type varieties, the plots were sown at a much lower density - 100 seeds/sq.m.

Site 1 - Southwest Manitoba - The stands were acceptable but variable, and the average stand by harvest time was only about 32% of the seeds sown (Table 3). Considering the late sowing, seed yields were excellent, with the French varieties Fedora 19 and Felina 34 exhibiting by far the highest yields. Small plot yields tend to overestimate yield potential on a field-scale - yields of Zolotonosha 11 and 13 on field scale in Manitoba yielded approximately half of the yields in this small plot trial. Δ9 - THC samples taken in approximately mid-flowering tested well below the 0.3% maximum allowed under the terms of the research licenses.

Site 2 - Central Manitoba - Because yield was variable at this site (note high coefficient of variation for seed yield - Table 4), cultivars cannot be declared to differ significantly in yield. However, the yields of the two French varieties (Fedora 19 and Felina 34) were highest, as at Wawanesa. Varieties did not differ significantly for flowering, maturity or height in this study. Stand counts were taken soon after emergence, and it appears that Fedora 19 and Felina 34 exhibit a higher degree of germination and/or vigor than the other varieties (germination tests were not conducted).

Site 3 - No data were taken - significant snow fell before the plots could be harvested, and there was significant bird damage.

Table 3 - Agronomic characteristics and Δ9 - THC content for hemp cultivars grown at seed density (100 seeds/sq. in.) - 1996 Southwest Manitoba.

Cultivar

Stand

plants/m2)

Seed Yield

Δ9 - THC

(%)

(kg/ha)

(lb /acre)

Zolotonosha 11

30

930 bc†

830 bc

<0.05

Zolotonosha 13

34

885 bc

790 bc

<0.05

Polish 1

32

820 c

732 c

0.05

Polish 2

28

691 c

617 c

0.11

Fedora 19

29

1567 a

1399 a

0.12

Felina 34

37

1228 ab

1096 ab

0.08

LSD (0.05)

NS

355

317

  

Average

32

1020

911

  

CV (%)

24.5

20.4

20.4

  

† Values within a column are significantly different if not followed by the same letter.

Table 4: - Agronomic characteristics and Δ9 - THC content for hemp cultivars grown at seed density (100 seeds/sq. in.) - 1996 Central Manitoba.

Cultivar

Stand

(plants/m2)

Days to Flower

Days to Mature

Height at Harvest (cm)

Yield

(kg/ha)

Yield (lb/acre) kg/ha x 0.8 g

Δ9 - THC

(%)

Zolotonosha 11

74 †

52

105

240

1056

844.8

<0.05

Zolotonosha 13

62

53

105

237

1074

859.2

<0.05

Polish 1

74

53

106

253

1528

1222.4

0.07

Polish 2

83

54

105

250

1561

1248.8

0.22

Fedora 19

92

58

108

243

1783

1426.4

0.11

Felina 34

96

53

106

253

1963

1570.4

0.09

LSD (0.05)

14

NS

NS

NS

NS

    

Average

80

54

106

246

1494

1195.2

  

CV (%)

11.4

5.9

2.5

4.1

26.9

    

† Values within a column are significantly different if not followed by the same letter.

Herbicide and Seed-placed Fertilizer Evaluation

Herbicides and Hemp - Although many claims are made that hemp's competitive ability makes herbicides completely unnecessary, there will be instances in which growers will utilize herbicides in weed management. We undertook an initial unreplicated screening to identify herbicides that might have potential from the perspective of crop safety - efficacy was not evaluated. Specific products cannot be mentioned without further study. While many common broadleaf products caused severe injury, a few caused minimal injury and may have potential. Note that before any herbicides could be recommended for use in hemp, the appropriate product registrations would have to be secured.

Seed-Placed Fertilizers and Hemp - An unreplicated trial was conducted to provide an initial indication of how tolerant hemp might be to seed-placed fertilizers. Stand reductions were evident when seed-placed N or P2O5 exceeded 20 lb/acre suggesting that hemp is moderately sensitive to seed-placed fertilizers. Further detailed study is required to verify this initial observation.

Insect Survey

An insect survey was conducted in August 1996 at the hemp site, using a sweep net. The insects collected were as follows:

  • 1 two-striped grasshopper
  • 1 migratory grasshopper
  • 1 nymphal grasshopper
  • 9+ lygus bugs
  • 1 wheat midge
  • 4 Gastrophysa polygoni (flower/foliage feeder in the leaf beetle family; main hosts are knotweed and wild buckwheat)
  • 1 stink bug
  • 6 syrphid flies
  • <100 aphids

3 types of damage were noted:

§ shot holes in leaves (could be either flea beetles or grasshoppers).

§ even patterned holes on both sides of leaf (likely bertha armyworm- this sample was collected during the day; therefore, bertha armyworm larvae would likely be resting under leaf litter).

§ leaf damage from the outer edge (likely grasshoppers).

These results suggest that the insect pests of hemp included bertha armyworm and grasshoppers. Other insect pests which are likely candidates for pest status include flea beetles (early season), lygus bugs (at flowering) and possibly aphids. Aphid numbers were high in 1996. Experience in 1995 shows that bertha armyworm (Mamestra configurata) can be a pest of economic significance.

Pollinators Associated with Hemp

The following are some of the insects observed foraging for pollen in hemp plots, based on limited observations during early blooming. Although some of the insects observed were in direct contact with hemp pollen, the question that remains to be answered, is whether these same insects will also visit the female parts (or flowers) of the hemp plant.

§ Honey bees were observed foraging for pollen in the hemp plot, even though there appeared to be no honey bee colonies within the immediate area (i.e. 2km2). Honey bees were by far the most abundant, (frequently observed) pollen foragers in the plots during our field observation. Hemp pollen was collected from the hemp flowers and compared to the pollen collected from the honey bees verifying that the pollen collected by the honey bees was indeed hemp.

§ Bumble bees were observed in the vicinity of the hemp plots, but no active foraging behaviour was recorded during our observations. Although no bumble fee foraging was observed in the sites, bumble bees were observed gathering pollen in a hemp field elsewhere in the province. A sample of pollen was collected from the bumble bees and found to contain hemp pollen.

§ Hover flies among several other dipteran insects (ie. flies) were observed in the hemp fields, but their contribution to the pollination of the crop is likely to be minimal.

§ Lygus bugs were found on several occasions in the male hemp flowers, but it is unlikely that they would contribute much to the transfer of pollen to the female flowers.

Fiber Quality Evaluation - Pulp

Approximately 800 lbs of hemp stalk in rectangular bales was sent to a small specialty paper company. In summary, while the company was able to pulp and manually make some attractive and functional card stock papers from the hemp, it was not considered it to be superior to what could be accomplished with flax straw. As flax straw is readily available and low cost, usage of hemp in this specialty market would not confer a high value to hemp - ie. growing hemp for this as a primary market would not likely be feasible. However, this may be a valuable outlet for hemp stalks recovered after harvesting grain hemp as an oilseed.

Seed Oil Quality Evaluations - University of Manitoba

Hempseed samples were analyzed for fatty acids (Table 5), antioxidants, and sterols (Table 6). The data confirm results from 1995 - hempseed oil is of merit nutritionally because of its relatively high level of gamma-linolenic acid (GLA) and antioxidants (compared with other edible vegetable oils). Without more data, we cannot be conclusive with respect to varietal or environmental differences. However, an examination of data to date suggests that varietal differences are present and may be more significant than environmental differences. Several varieties sourced in the Ukraine or Poland had levels of GLA in the range of 2.5 - 3.0%, for the original source seed and for seed grown from it at two locations in Manitoba. Three varieties sourced in Romania (Secuieni 1, Lovrin 110, and Irene) had lower GLA (1.2 -1.5%) - these three will be tested in the field in Manitoba in 1997.

Table 5: Summary of hempseed oil fatty acid analyses - Manitoba 1996. Typical levels for several other crops given for comparison (% of oil).

Fatty Acid in Oil

Hemp Seed

Canola

 Sunflower

Flax

Solin Flax

low

high
palmitic

5.9

6.4

3.5

7.2

7

 ┐
palmitooleic

0.1

0.2

       │ 12
stearic

2.4

3.4

1.5

4.1

4

 ┘
oleic

11.4

13.5

60.0

16.2

20

17
linoleic

54.8

57.7

20.0

72.5

17

71
linolenic

15.3

17.9

10.0

0.0

52

2
gamma-linolenic

2.4

3.6

        
arachidic

0.8

1.0

        
eicosenic

0.4

0.4

        
behenic

0.3

0.4

        
lignoceric

0.1

0.2

        
other

1.1

1.5

        

Table 6 - Summary of Hemp-oil analysis for antioxidants and sterols. Manitoba 1996 - 24 samples, various varieties and locations.

Oil Component Low (ppm) High (ppm)
Antioxidants    
µ - Tocopherol

5.6

19.1
β - Tocopherol

7.1

16.5
γ - Tocopherol

699.8

1101.3
δ - Tocopherol

19.8

68.3
µ - Tocotrienol

15.4

46.5
     
Sterols    
β - Sitosterol

2384

4204
Stigmasterol

101

221
Campestrol

726

1401
Brassicasterol

33

122

Economic Analysis

Detailed and summary cost vs return estimates are provided in Tables 7 and 8, respectively, for the situation we believe to be most readily accessible for Manitoba: growing hemp for grain, with harvest of the low-grade stalks remaining after the grain has been harvested. These analyses are laden with assumptions, but serve to indicate whether or not we are "in the right ballfield".

The estimated total production costs in Table 8 are for hempseed alone, then added to these is the estimated cost of cutting and baling the remaining stalk. The estimated returns are given as a worst case (low yield, low price) to best case (high yield, high price) range - reality is likely to be somewhere in between the range extremes.

The results suggested that hemp seed by itself may not be economically feasible from a farmer’s perspective, if the price settles to approximately 15¢/lb. in the long run. Harvest of the remaining stalk for low end use in pulp or particle board manufacture seems to make for a reasonably attractive scenario - ie a positive net return is likely.

Further development efforts are warranted, but one of the assumptions here is that readily accessible markets exist - in reality, such markets will take time to develop and stabilize. However, only actually growing and marketing hemp stalk or grain on a commercial basis will be the final proof of economic feasibility.

Table 7: Hemp seed stalk scenario - costs vs. returns summary (est. Feb/97 - Jack Moes, Manitoba Agriculture)

 

Hemp seed $/acre

Hemp seed $/acre

Residual Stalk $/acre

Residual Stalk $/acre

Canola $/acre

Your Farm
Operating Costs: Seed

$21.00

$21.00

$0.00

$0.00

$24.00

  
Fertilizer

$43.40

$43.50

$0.00

$0.00

$37.35

  
Chemicals

$20.00

$20.00

$0.00

$0.00

$29.00

  
Fuel

$11.00

$11.00

$4.00

$4.00

$11.00

  
Machinery Operating Costs

$15.00

$15.00

$6.00

$6.00

$10.00

  
Crop/Hail Insurance

$6.00

$6.00

$0.00

$0.00

$11.65

  
Other Costs

$7.50

$7.50

$0.00

$0.00

$7.50

  
Drying Costs

$0.00

$0.00

$0.00

$0.00

$0.00

  
Interest on Operating

$4.51

$4.51

$0.35

$0.35

$4.73

  
TOTAL OPERATING COSTS

$134.01

$134.01

$10.35

$10.31

$140.73

  
Fixed Costs: Land Investment Costs

$16.00

$16.00

$0.00

$0.00

$16.00

  
Machinery Depreciation

$17.50

$17.50

$5.00

$5.00

$17.50

  
Machinery Investment Costs

$7.00

$7.00

$7.50

$7.50

$7.00

  
Storage Cost

$2.14

$2.14

$2.14

$2.14

$2.14

  
TOTAL FIXED COSTS

$42.64

$42.64

$14.64

$14.64

$42.64

  
TOTAL OPERATING AND FIXED

$176.65

$176.65

$24.99

$24.99

$183.37

  
Labour

$13.50

$13.50

$13.50

$13.50

$13.50

  
TOTAL COSTS

$190.15

$190.15

$38.49

$38.49

$196.87

  
             
Price/lb

$0.15

$0.30

$0.03

$0.03

$0.14

  
Expected Yield (lb)

500

1000

3000

5000

1400

  
Total Return

$75.00

$300.00

$90.00

$150.00

$196.00

  
CASH SURPLUS ABOVE TOTAL

- $115.15

$109.85

$51.51

$111.51

- $0.87

  
             
Breakeven Yield (lb): Operating

893

447

345

345

1005

  
Operating and Fixed

1178

589

833

833

1310

  
Total

1268

634

1283

1283

1406

  

Table 8 - Hemp seed/stalk scenario - costs vs returns summary (est. Feb/97 - Jack Moes, Manitoba Agriculture)

 

Hempseed

Additional for residual stalk

Hempseed + stalk
Cash costs

134

10

144
Non-cash costs

56

29

85
Total costs

190

39

229
Price/lb

0.15 to 0.30

0.02 to 0.03

  
lb/acre

500 to 1000

3000 to 5000

  
Total return

75 to 300

90 to 150

165 to 450
Return above cash costs

-59 to 166

  

21 to 306
Return above total costs

-115 to 110

  

-64 to 221

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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