Industrial Hemp Agronomic Trials Western Australia, Sept 1996 – May 1997


An agronomic trial program was implemented in the southwest of western Australia
 to examine growth and production of six European cultivars of industrial (low-THC) hemp. The trials were planted on eight farms located at Carnamah, Wagerup, Burekup, Mullalyup, Manjimup, Scott River, Denmark and Two peoples Bay in the spring of 1996.

Licenses were issued to the eight participating farmers and two research officers from Agriculture Western Australia under the Poisons Act 1964, administered by Health Western Australia.

The crops grew slowly in the cool weather of October and flowered prematurely, restricting final yields — all cultivars flowered six weeks after planting at every site. Yields were very low by national and international standards. These results show that the European cultivars available are unsuited to the Western Australian environment. Furthermore, they showed no consistent response to irrigation. These results are consistent with reports from other States.

The trial program was publicized widely, and attempts made to create interest in processing the raw product. No serious interest in processing hemp into pulp for paper, yarn for textiles or fiber for building materials, was expressed to the Industrial Hemp Steering Committee or to Agriculture Western Australia by June 1997, It is therefore concluded that there is no potential for an industrial hemp industry on a large scale in Western Australia. There may be some potential for cottage industries based on hemp, however, and a small project is recommended to examine this prospect further.


 Trials should continue at Denmark and include two additional cultivars of low-THC hemp from the Netherlands.

2.2 The remaining seven trials should be terminated, as it is unlikely they will produce sufficient additional information to justify the cost to the participating farmers or the New Industries Program. The farmers are licensed to continue with trials for another two years, but they will be required to meet all costs, as stated in the license conditions -“All services by government agencies will be provided on a fee for service basis.” (Appendix B). During the first year, services provided by the Agriculture Western Australia coordinators were not charged for.

2.3 A small trial should be implemented on the Ord River Irrigation Area provided a Kununurra-based officer of Agriculture Western Australia can be issued with a license and costs kept to a reasonable level. This trial would provide information from the extreme range of environments in the State; however, the cultivars adapted to European latitudes above 460 are likely to be even less suited to the low latitudes of Kununurra (160) than they are to the agricultural areas in the south-west of the State (350 to 280).

2.4 The focus of industrial hemp activities should shift towards the development of small, cottage craft industries, should the demand arise. One or two restricted licenses could be issued to enable interested parties to test the potential for small-scale development. The Minister for Health can issue such licenses under section 41A of the Poisons Act 1964, according to advice from the Attorney General to the Industrial Hemp Steering Committee in a letter dated 30 June 1995. The letter states:

“The offence provisions of the Misuse of Drugs Act 1981 and the licensing provisions of the Poisons Act 1964 are sufficient to form the basic legal framework for legal commercial hemp production.”; and

“Section 41A of the Poisons Act 1964 states:

(1) Subject to this Act the Commissioner of Health may grant for any person a license to cultivate, sell, purchase or have in his possession any prohibited plant.

(2) A license granted pursuant to this section shall be subject to such conditions as may be prescribed and as the Commissioner of Health may in his discretion impose.”

3. BACKGROUND In 1995, the Minister for Primary Industry and Fisheries, Monty House MLA established a Ministerial Review Committee to examine prospects for an industrial hemp industry in Western Australia. The committee’s Terms of Reference included agronomic, economic and legal aspects of such an industry. The committee concluded that:

  • There is strong and widespread public support for a hemp industry in WA. There were over 140 written submissions, and 176 people attended the public meetings; almost all of these were in favor of an industrial-Hemp industry.
  • There is no significant market for hemp fiber (for paper or fabric manufacture) in Australia at present; although, one Western Australian company is proposing to establish a processing plant for exporting paper pulp, and several people have expressed interest in establishing cottage industries based on fabric.
  • Industrial hemp grown for fiber and cannabis grown for drugs are closely related cultivars of the plant species, Cannabis Sativa L., which is prohibited in Australia (Appendix A). As the two types appear identical, fiber hemp is prohibited and can not be grown either commercially or experimentally without approval from the Minister for Health under the Poisons Act 1964,
  • Hemp is a summer crop, which flowers and matures in autumn (short-day plant), so will probably need irrigation to grow well in the southwest of WA. An experimental program was needed as, in the absence of data from local trials or practical experience, this conclusion was based on a computer model relating crop growth with climate. The model, PlantGro ™ (Hacket 1991), indicated that the temperatures, daylength and soil properties in southwestern Australia were not favorable for fiber hemp production.

The committee recommended the implementation of a small agronomic trial program for industrial hemp in Western Australia, to be conducted and funded by the private sector under the guidance and supervision of the Industrial Hemp Steering Committee. The Steering Committee, with representatives of the Health Department, the Police Department, Agriculture Western Australia and the farming community was established to:

Develop conditions attached to, and protocols for, licenses to grow industrial hemp for experimental purposes; and

· Select participants to implement trials under license.

The system of licensing and conducting trials on private farms developed by Agriculture Victoria was adapted for Western Australia. Conditions and protocols attached to licenses were designed to satisfy the security requirements of the Departments of Health and Police (see Appendix B).

Advertisements seeking expressions of interest in participation in a trial program were lodged in various media. From the 54 applications subsequently received, eight applicants were selected and issued with licenses to grow industrial hemp. The licensed farmers were required to meet the costs of production and security of hemp grown in the trials, and were not permitted to sell any material produced in the trials. The trials were located at Carnamah, Wagerup, Burekup, Mullalyup, Scott River, Manjimup, Denmark and Two Peoples Bay (Albany).

Two research officers from Agriculture Western Australia were issued with licenses to be in possession of Cannabis Sativaseed and parts of plants grown from it. Their duties included:

  • The design and coordination of all trials;
  • Monitoring and recording observations at critical stages of growth;
  • Harvesting, drying and weighing samples for measurement of stem production; and
  • Taking samples of flowers for testing for level of THC.
  • Analyzing data and preparing reports.

4. GENERAL APPROACH The general approach is described in this section; individual differences in design and operation are covered in the detailed description of each site.

Each site was chosen to represent commonly available soil types in areas of greatest production potential. Four sites compared irrigation with natural rainfall, and the other four were not irrigated.

Six cultivars were selected from the published list of certified, low-THC hemp varieties, available from research institutions in Europe (de Meijer 1995). These had been bred for quantity and quality of industrial fiber, and had been tested and accepted as commercial crops. To cover the range of flowering types, two early flowering cultivars, two medium, and two late flowering cultivars were chosen for the trials. These had all been tested elsewhere in Australia with varying success, but all were proven low-THC types. The group was made up of five French cultivars — Ferimon 12, Fedora 19, Felina 34, Fedrina 74 and Futura 77 — and one from the Netherlands — Kompolti.

The trials were planted in spring into well-prepared seedbeds. Three to four weeks before planting, the sites were sprayed with a total knockdown herbicide (glyphosate). They were cultivated and worked back a few days before seeding.

The crops were planted with cone seeders at a depth of 20 to 30 mm and at a rate calculated to produce 260 viable seedlings per square meter (approximately 50kg of seed per hectare). The germination rate was tested and the average weight per 100 seeds was measured on samples of each cultivar to determine the weight of seed required for each plot. The plots at all sites, except two, were 50 meters long and 1.44 meters wide, each with eight rows of plants; the length of the plots at Wagerup and Burekup were reduced to 30 meters.

Fertilizer (a 3 to 1 mixture of Agras No. 1 and Muriate of Potash providing N:P:K:S in the ratio 13.1 : 5.7 : 12.5 : 12.7) was applied at 200kg per hectare on the rainfed crops and 400 kg per hectare on the irrigated crops. The higher rate provided approximately 25 kg of nitrogen, 50 kg of Phosphorus and 25 kg of potassium per hectare. This was applied on the surface of the soil in front of the planting tines to prevent excessive concentration around the seed.

Three weeks after planting, the density of establishment of seedlings was estimated by counting the number of viable plants in a one meter-wide strip across every plot.

The crops were harvested approximately three weeks after flowering was first observed and before seed-set was completed. At harvest, the average height of the plants was measured, and a sample from each plot was cut at ground level from an area of 1.44 square meters. These samples were oven dried and weighed to estimate total yield of dry matter. The yield of stems was estimated by separating the stems from the leaves and flowers in representative samples and weighing each component.

Statistical analysis of data was performed using Genstat. Least Significant Differences (LSDs) are included in the tables of results in Section 4.

Female flowers were cut from 40 plants of each cultivar grown at each site immediately before harvest and analyzed at the Chemistry Center (WA) for level of THC (delta-9-Tetrahydrocannabinol). The maximum allowable level, under the conditions of the licenses, is 0.35% THC (w/w). These test results are presented in Appendix C.


5.1 Carnamah
5.1.1 Site details
The site is south of Lake Yarra Yarra. The soil consisted of pate and yellow deep sands at the lower end of the site, and grey, deep, sandy duplex soils at the higher end (Launer 4 association).

The mean daily temperatures recorded at Carnamah (20 km northeast of the site) during the growing period are shown in Table 1.

Table 1. Mean daily maximum and minimum temperatures for September to December, 1996 at Carnamah
(variation from long term averages are in brackets)

Mean max.20.9 (-1.2)26.9 (+1.2)31.3 (+1.5)33.3 (-0.1)
Mean min.9.1 (+1.0)11.5 (+1.3)14.3 (+1.3)15.9 (+0.1)

5.1.2 Design

Treatments:Five cultivars (all except Kompolti which was planted in the buffers)
Rainfed vs. irrigation (using overhead sprinklers)

The rainfed plots received 35 mm, 7 mm and 16 mm of rain in September, October and November. The irrigated plots received an additional 27-mm, 96-mm and 9 mm through overhead sprinklers in the same months.

5.1.3 Results
The germination rate was a little over half of the anticipated 260 plants per square meter, yet as high as that observed in the other trials.

The rainfed crop failed to grow and was not harvested. The irrigated crop grew poorly, and reached about 35 centimeters at flowering (45 days after germination). The yield was estimated from samples taken from three 1.44 square meter quadrate cut from each plot. The samples were pooled within plots and across replicates, partially air-dried, and weighed.

Table 2. Plant establishment and air-dry yield at Carnamah

Plants established per sq. meterYield (air dry) Tonnes/ha
Ferimon 121901371.19
Fedora 191861531.19
Felina 341751500.89
Fedrina 741401301.33
Futura 771351551.24

5.2 Wagerup 
5.2.1 Site details
The site is located on an irrigation bay, Wagerup, 5 kilometers southwest of Waroona. The soil system is gently undulating Pinjarra Plain, deep acid mottled yellow duplex soils with moderately deep sandy loam topsoil over clay subsoil.

The bay, 35 meters wide and about 450 meters long, was divided into two long sections by an earth mound to enable one side to be flood-irrigated, leaving the other side dry (rainfed).

Rainfall during the growing period was recorded at the Waroona Post Office — Table 3.

Table 3, Rainfall recorded at the Waroona Post Office, October 1996 to January 1997 compared with the long-term means.

Total (mm)6064224
Average (mm)62331415

The first time of planting received 86 mm while growing, and the second time of planting received 44 mm while growing.

5.2.2 Design

Treatments:Six cultivars
Flood irrigation vs. rainfed
Two times of planting (31 October vs. 19 November)

5.2.3 Results
First planting — sown on 31 October and harvested after 47 days.

The plants germinated quickly, but grew slowly. Rainfall was above average and the plots were not irrigated until after harvest, so the differences between the “irrigated” and “rainfed’ blocks was due to differences in fertilizer application — the irrigated block received 400 kg of the fertilizer mix and the rainfed block, 200 kg per hectare.

Table 4. Plant establishment, final height and yield of dry matter, first time of planting — Wagerup

 Plants per sq. meterHeight (cm)Yield (Tonnes/ha)

One replicate was harvested after a further 20 days of growth (day 67). The dry matter yield of the irrigated plots increased from 2.8 to 3.9 tonnes/ha; and the rainfed, from 1.2 1.8 tonnes/ha.

Mean stem diameter at harvest in the rainfed block was 3.32 mm, and in the irrigated block was 4.18 mm.

Statistical analysis
Statistical analysis (Appendix C) showed that the cultivars differed significantly only in the establishment counts:

  • On the irrigated block, Fedora had a higher establishment count than Ferimon, Futura and Kompolti, while Felina had a higher count than Ferimon and Futura.
  • On the rainfed block, Fedora had a higher count than Ferimon and Futura, while Felina was higher than Ferimon.

Second planting — sown on 19 November 1996 and harvested after 71 days. The irrigated plots all died; the data in Table 5 is from the rainfed plots.

Table 5. Plant establishment, final height and yield or dry matter, second time of planting — Wagerup.

CultivarPlants per m2Plant Height (cm)Yield (Tonnes/ha)

Statistical analysis
The statistical analysis (Appendix C) showed that the following differences were significant:

· Kompolti, Fedora and Fedrina had higher establishment counts than Ferimon.

· 9 Futura and Kompolti grew taller than Fedrina and Fedora.

· Felina grew taller than Fedora.

5.3 Burekup 
5.3.1 Site details
The site is located on the irrigated flats 2 kilometers east off Burekup. The plots were planted in an irrigation bay divided into two long rectangular areas, 17 meters wide and 80 meters long, separated by an earth mound, allowing one side to be kept ‘dry’ and the other flood-irrigated.

The soil-landscape system, the Pinjarra Plain (Sub Unit P1 b), is a broad, low relief plain west of the Darling Scarp foothills. The soils are derived from predominately Pleistocene fluvial sediments and some Holocene alluvium associated with the major drainage systems. The soil is a sandy loam over clay. It is imperfectly drained and moderately susceptible to salinity at the lower end of the site.

The total rainfall and mean daily temperatures recorded at the Bunbury Racecourse (15km southwest of the site) for the months of October, November and December, 1996 are shown in Table 6.

Table 6. Rainfall and temperatures recorded at the Bunbury Racecourse, October to December 1996

Total (mm)384032
Average (mm)522613
Mean max.(°C)20.923.425.5
Mean min. (°C)

The crop received 76 mm of rain while growing.

5.3.2 Design

Treatments:Six cultivars
Flood irrigation vs. rainfed

This trial was planted on 31 October and harvested after 54 days. The irrigated bay was flooded once, two weeks after planting.

5.3.3 Results
Irrigation caused many plants to die and others to become chlorotic and burn at the leaf margins — typical signs of excessive salinity and waterlogging. The results in Table 7 show that the plants did not recover fully from this setback.

Table 7. Plant establishment, final height and yield of dry matter — Burekup

 Plants per sq. meterHeight (cm)Yield (Tonnes/ha)

Mean stem diameter at harvest was 3.83 mm in the irrigated block, and 5.31 mm in the rainfed block.

Statistical analysis
There were no statistically significant differences between cultivars.

5.4 Mullalyup 
5.4.1 Site details
The site is 2 kilometers east of Mullalyup on the lower slopes of the Balingup Subsystem which has moderately sloping, deeply incised valleys with loams. The soil is a well-drained grey-brown loam over a lateritic gravel interface with the mottled yellow clay subsoil.

5.4.2 Design

Treatments:Five cultivars (all except Felina which was planted in the buffers)
Urea (60 kg/ha) vs. Urea (60 kg/ha) plus CLM. seed and soil treatment

Immediately before planting, the seed from the CLM block (Creative Land Management) was treated with bacterial slurry, and after planting, the block was hand top-dressed with the company’s ground granite product.

The trial was planted on 8 October 1996 and harvested after 56 days.

5.4.3 Results
There was a good germination of hemp, but wild radish germinated at the same time. Where the radish was dense, the hemp did not compete and grew poorly.

Table 8. Plant establishment, final height and yield of dry matter — Mullalyup

CultivarPlants per sq. meterHeight (cm)Yield (Tonnes/ha)

Mean stem diameter was 3.68 mm at harvest.

Statistical analysis
The statistical analysis (Appendix C) showed that the following differences were significant:

Fedora had a lower establishment rate than the other cultivars. Futura and Fedora grew taller by harvest than Ferimon and Kompolti.

5.5 Manjimup 
5.5.1 Site details
This site, located 6 Kilometers south of Manjimup, represents the red earths (also known as karri loams) of the Pemberton Subsystem. The topsoil is red-brown loam over gravelly, mottled yellow clay at 60-cm depth.

The rainfall recorded at the nearby Manjimup Horticultural Research Station, for the period October to December 1996 is shown in Table 9, and temperatures recorded in Manjimup are in Table 10.

Table 9. Rainfall recorded at the Manjimup Horticultural Research Station, October to December 1996, compared with long term averages.

Total (mm)764782
Average (mm)794725

Table 10 Mean daily maximum and minimum temperatures for October to December 1996, recorded in Manjimup
(variation from long-term averages are shown in brackets).

Mean max. (°C)19.2 (+0.6)23.1 (+1.5)22.5 (-2.1)
Mean min. (°C)8.9 (+0.7)11.5 (+1.5)10.8 (-0.7)

5.5.2 Design

Treatments:Five cultivars (all except Fedrina, which was planted in the buffers)
Urea (60 kg/ha) vs. Urea (60 kg/ha) plus CLM. seed and soil treatment

The trial was planted on 16 October 1996 and harvested after 49 days.

5.5.3 Results
Germination was generally good but uneven, probably because the site was being cropped for the first time and was too uneven to control the depth of planting. The southern end of the site was wetter than the remainder, and the plants there showed poor germination and growth

Growth over parts of the site was vigorous and continued well after harvest, indicating that it may have been harvested prematurely

Table 11. Plant establishment, final height and yield of dry matter — Manjimup.

CultivarPlants per sq. meterHeight (cm)Yield (Tonnes/ha)

Statistical Analysis
No differences were statistically significant.

5.6 Scott River 
5.6.1 Site details
The site is 40-km southwest of Nannup, in the northeast region of the Scott River Plain Land System. The soil is deep, bleached siliceous sand over a clay subsoil, with a high water table in winter and moisture near the surface in summer.

The total monthly rainfall on the property, recorded by Denis Avery for the months of October, November and December 1996 was 68,27, and 96 mm. The crop received 131 mm during growth.

5.6.2 Design

Treatments:Six cultivars

The trial was planted on 6 November and harvested after 75 days.

5.6.3 Results
After an even germination, the plants grew vigorously until heavy rain (80 mm in one day) on 12 December inundated the plots. Water lay on the surface over about one-third of the site for nearly three days. All plants on the wet areas died from waterlogging within a week. MI sampling and measurements were taken from the surviving areas which continued to grow vigorously until harvest.

Table 12. Plant establishment, final height and yield or dry matter — Scott River.

CultivarPlants per sq. meterHeight (cm)Yield (Tonnes/ha)

Mean stem diameter at harvest was 7.48 mm.

Statistical analysis
Differences between the cultivars were statistically significant in height and yield.

· Futura and Kompolti grew taller than the other cultivars.

· Futura had a higher yield than Ferimon, Felina, and Fedrina.

· Kompolti had a higher yield than Felina and Fedrina.

· Fedora had a higher yield than Fedrina, but was not significantly different from the two highest yielding cultivars, Futura and Kompolti.

5.7 Denmark 
5.7.1 Site details
Located 1 kilometer east of Denmarkthis site is on weathered siltstone and sandstone. The soil is duplex with light brownish grey fine sand over lateritic gravel at 50 to 60 cm below the surface, at the interface of the clay B-horizon.

The total rainfall for the period October 1996 to January 1997, recorded at the Denmark Post Office, 3 kilometers west of the Denmark Agricultural College, are shown in Table 13.

Table 13. Rainfall recorded at the Denmark Post Office, October 1996 to January 1997, compared with long term average falls for those months

Total (mm)117385919
Average (mm)100523527

5.7.2 Design

Treatments:Five cultivars (all except Futura, sown in the buffer plots)
Rainfed vs. Irrigated with overhead sprinklers

The trial was planted on 7 November 1996 and harvested (samples taken to estimate yields) at 60 and 90 days after planting.

Water was applied to the irrigated plots under the schedule shown in Table 14.

Table 14. Irrigation schedule for Industrial Hemp — Denmark

DateWater applied (mm)
11 December32
18 December30
20 December25
23 December10
27 December25
31 December35
2 January25
9 January25
2 February15

By the first harvest-date, the irrigated plots had received 172 mm through the sprinklers in addition to 214 mm of natural rain. By final harvest the irrigation supplied 222 mm in addition to 233 mm of natural rain.

5.7.3 Results
During the first two weeks after planting, germination was uneven and growth was slow, but then the crop improved rapidly.

The first harvest samples were taken on 6 January — three weeks after the initiation of flowering — and showed little difference between the rainfed and irrigated blocks (5.17 vs. 7.82 tonnes per hectare). However, during the next 30 days, the irrigated block yielded an additional 4.84 tonnes of dry matter, while the rainfed block added only 2.38 tonnes. Hemp i~ normally harvested at the stage of maturity represented by the first harvest date — between flowering and seed-set — to ensure that the fibers can be readily separated from the rest of the plant, and from each other, during processing. The first harvest, therefore, gives the more realistic estimate of likely yield for fiber production.

Table 15. Plant establishment, final height and yield of dry matter- Denmark

CultivarPlant count 4/12/96Height (cm) 6/1/97Yield (Tonnes/ha) 6/1/97Height (cm) 5/2/97Yield (Tonnes/ha) 5/2/97
Fedora 191631255.511369.09
Felina 341811295.501369.28
Ferimon 121501245.381248.20
Fedrina 741731295.781389.35

Statistical Analysis
· Kompolti was taller than the other cultivars at the second cut. The cultivars were similar in al other measurements.

· The Least Significant Differences shown in the table apply to cultivars only.

5.8 Two Peoples Bay (Albany) 
5.8.1 Site details
The site is located 30 kilometers east of Albany, in Two Peoples Bay Road, in a shallow valley of deep, leached sand which is grey brown at the surface, white-grey below 15 cm and with some lateritic gravel. The lower end of the site is adjacent to a summer-moist drainage line of humus podzol soil.

Rainfall was recorded at the site, and temperatures, at the nearest recording station (Albany town, 30 km west of the site) are shown in Tables 16 and 17.

Table 16. Rainfall recorded at Two Peoples Bay, October to December 1996

Total (mm)594028

Table 17. Mean daily maximum and minimum temperatures (degrees centigrade) for October to December 1996, recorded at Albany town (variation from long term averages are shown in brackets)

Mean max. (°C)18.820.9 (+0.1)20.7 (-2.8)
Mean min. (°C)9.4 (+0.4)11.0 (+0.4)11.6 (-0.7)

5.8.2 Design

Treatments:Five cultivars (all except Fedrina, planted in the buffer plots)

Initially it was planned to plant two separate blocks: one in the valley floor, straddling a “Summer-moist” drainage line; and one higher on the mid-slope. The plan changed at the time of planting as the unusually wet winter made the valley floor too wet and soft for the planting machinery. The first block was planted along the contour adjacent to the wet area, and the other, higher up the slope. As there appeared to be no effect due to distance from the moist area, the two blocks with four replicates each were treated as one block with eight replicates.

5.8.3 Results
The Kompolti was slow to germinate, but the other cultivars had high establishment counts. Growth at this site was generally poor.

Table 18. Plant establishment, final height and dry matter yield of industrial hemp sown at Two Peoples Bay

CultivarPlants per sq. meterHeight (cm)Yield (Tonnes/ha)

Statistical analysis
The only significant treatment effect was due to the low germination and establishment of the Kompolti.

6. PLANT GROWTH AND DEVELOPMENT Plant growth and development was monitored during the growing season on the Burekup site and development stages were observed during visits to the Wagerup and Scott River sites.


Leaf Development
Leaves emerged at a rate of one leaf pair each five days over the 54-day growing period, with the rate of leaf emergence increasing slightly towards plant maturity. There was little difference in rate of leaf emergence between cultivars.

Plant Growth in Height
Plants grew in height at about 1.5 cm per day for the first 36 days of growth but growth rate increased towards maturity so that growth rate from planting to harvest (day 54) was 1.8 cm per day.

There was little difference between cultivars in early season growth, but later maturing Futura 77 and Kompolti increased final stem growth rate to produce longer stems at harvest.

Flowering and Seed DevelopmentSeed development began at anthesis, with the ovule growing to reach final size at the watery dough stage of development. From the watery dough stage, seed developed through soft and hard dough stages as the seed and seed coat hardened to the final hard mature seed.

First fertilization of female flowers started about 40 days after planting. Seed of early maturing Ferimon 12 and Fedora 19 had reached watery dough stage by day 48. Felina 34, Fedrina 74 and Futura 77 were at the watery dough stage by day 54. Kompolti had not started flowering on the dioecious female flowers when the trial was harvested on day 54. At final observation on day 61, some dioecious female plants were flowering, but these were a small proportion of the population.

Thermal time (cumulative mean daily temperature since planting (degree-days)) was calculated from Bunbury Racecourse temperature data.

Flowering started after about 700-degree days of thermal time, 40 days after planting, for all cultivars except Kompolti. Most Kompolti dioecious female plants had not started flowering by day after 61-degree days of thermal time.

At Wagerup, 47 days after a 31 October planting, Ferimon 12 and Fedrina 74 had reached the watery dough seed development stage, Felina 34 was approaching the watery dough stage and Fedrina 74 and Futura 77 had recently flowered. Kompolti dioecious females were not fertilized.

Thermal time calculated from Wokalup Research Support Unit temperature data (28 km south of the trial site) showed that about 880-degree days of thermal time had been received in the 47 days of growth.

From the 19 November planting, after 48 days, about 1000-degree days of thermal time had been received. At this time Ferimon 12 and Fedora 19 were about halfway between anthesis and watery dough stage, Fedrina 74 was recently fertilized and Felina 34, Futura 77 and Kompolti had not reached anthesis.

On 31 December, 55 days after the 6 November planting, (950 degree-days of thermal time) Ferimon 12, Fedora 19, Felina 34 and Fedrina 74 had developed to the watery dough stage. Futura 77 was between anthesis and watery dough stage and Kompolti dioecious female plant. had not reached anthesis. (Thermal time was calculated from temperature data from Pemberton and Nannup).

Anthesis commenced at these three sites about 40 days after an early November planting, after 700 to 800 degree days of thermal time. Ferimon 12 and Fedora 19 reached anthesis earliest with Felina 34, Fedrina 74 and Future 77 several days slower. Most Kompolti dioecious female plants did not reach anthesis within the duration of these trials, up to 75 days and more than 1300-degree days of thermal time.

7. SUMMARY OF RESULTS Yields of dry matter were generally well below those reported from Tasmania and Victoria where the same cultivars were tested) and from Europe where very high yields are commonly reported. Some — but certainly not all — of this discrepancy is undoubtedly due to the different method of estimating productions in Western Australia, samples were oven-dried in a forced draft of air at 60°C. for three days before weighing, while the Victorian estimates were from air dried samples which would have retained higher and variable amounts of moisture. Even allowing for this factor, however, the European hemp cultivars were clearly unsuited to Western Australian conditions. Not only were yields of dry matter low, but the plants matured at heights between 0.5 and 1.4 meters — heights of three meters are commonly attained in Europe, and two meters in eastern Australia,

Early growth at all sites was slow, and the plants did not compete well with weeds. Vigorous growth occurred between three and six weeks at most sites, but flowering was earlier than expected and ended vegetative growth by approximately 60 days.

The cultivars all flowered within 40 to 45 days of germination, whether planted in early, mid-or late spring. At Denmark, flowering occurred after only 22 days with the January planting, and after 15 days with the self-sown crops which germinated in mid-February. Surprisingly, the ‘late-maturing’ Kompolti male plants were first to flower followed a few days later by female and bi-sexual plants of all other cultivars. The Kompolti females were appreciably slower to develop than the flowers of the other cultivars, so vegetative growth continued longer in that cultivar.

Germination was lower than expected from the laboratory measurements on samples of the seed. Seeding rate was set to provide 260 plants established per square meter, but the highest count was 212 plants per square meter at Manjimup, and the lowest, 93 at Burekup. The lower density was not compensated by more vigorous growth of individual plants, as the stems were generally thin and short compared with reported standards.

Hemp appears to be highly susceptible to waterlogging. The flood irrigated plants died surprisingly quickly, and the well-established plants on the sandy soil at Scott River died when inundated for three days after one heavy rainfall — 80 mm fell in 24 hours in early December. At other sites, growth was consistently poor where particular areas within the sites were wetter than average; at Denmark, for example. where the highest yields were attained, depressed growth was obvious in circular areas around each sprinkler head. These observations were consistent with reports of outright failure of flood irrigated crops in Victoria and unusually wet sites in Tasmania,

Crop growth did not seem to be strongly related to soil type. Growth was poor on the shallow clays at Wagerup and Burekup, not only due to flood irrigation. Low yields were also recorded on the deep sands at Carnamah and Two Peoples Bay; however, vigorous growth occurred at Scott River on deep leached sands. The results on the karri loam at Manjimup were below expectation, while the fine sandy soil at Denmark provided the highest yields.

Common crop pests were observed on the hemp at all sites. Native budworm (Helicoverpa punctigera), African black beetle (Heteronychus arator), Rutherglen bug (Nysius vinitor) and brown pasture looper (Ciampa arietaria) were active at all stages of growth of the crops at most sites, but did not appear to reduce production. In the Victorian trials, the heliothis caterpillars were apparently active only on the developing seed heads.

As expected, the hemp produced acceptably low levels of THC (the prohibited drug, delta-9-Tetrahydrocannabinol). The levels were all well below the legal limit of 0.35%, ranging from 0.1204 down to levels below the limits of reliable reading for the test procedure.

8. CONCLUSIONS The hemp cultivars tested in this trial program do not appear suited to the Western Australian environment. They were all bred in, and therefore adapted to high latitude regions above 48C while the Western Australian agricultural areas are alt below 350, Despite an abnormally favorable season for late spring growth, with late rains and mild weather, yields were not encouraging.

The development of cultivars suited to this environment would need a long and expensive breeding program. It is unlikely that such resources would be allocated to industrial hemp at this time because there are no significant local markets for raw hemp; furthermore, transport storage and handling costs would present practical difficulties and make export markets uneconomic, according to the latest study, “Some Opportunities for Hemp Products in Australia”, commissioned by the Rural Industries Research and Development Corporation (IURDC Research Paper No 97/31).

Security was adequate at all sites, with only one reported and unsuccessful — attempt of unauthorized entry to a site. The levels of THC were all well below legal limits.


We gratefully acknowledge the following for their assistance and advice:

  • the participants in the trials who obtained licenses, committed their time and resources to the project and were most helpful throughout.
  • The Librarians, and staff of the library, Agriculture Western Australia, who always respond professionally and quickly to our many requests for help
  • The biometricians, for their advice and instruction.
  • The Industrial Hemp Steering Committee — State Crime Squads, Police Department.
  • Document Support Center, Agriculture Western Australia, for their assistance in preparing the manuscript

10. REFERENCES Hannay, J. and Graham, C. (1995). Industrial Hemp. A report from the Yorke Regional Development Board, South Australia,

Lisson, S. and Mendham, N. (1995). Hemp (Cannabis sativa) — a Potential Multi-purpose Crop for Tasmania. A report from the Department of Agricultural Science, University of Tasmania.

Lolicato, S., Bluett, C. and Blackstock, 1(1996). Low-THC Indian Hemp (Cannabis sativa Trials in Victoria. A report for the First New Crops Conference, University of Queensland, July 1996

Meijer, E. de (1995). Fibre hemp cultivars: A survey of origin, ancestry, availability and brief agronomic characteristics, Journal of the International Hemp Association, Volume 2, Number 2.

“Some Opportunities for Hemp Products in Australia”, a study commissioned by the Rural Industries Research and Development Corporation (RIRDC Research Paper No.97/31).

Perry, M (1995). Fibre hemp production in the south-west land division of western Australia environmental suitability. in: Industrial Hemp, Prospects for and Industry in Western Australia, Appendix E, Ministerial Review Committee Report to the Minister for Primary Industry and Fisheries, Hon Monty House MILA, October 1995.

Reichert, G. (1994). Government of Canada Report on Hemp. Published by the Policy Branch of Agriculture and Agri-food Canada. Vol.7 No.23.

Van der Werf H.M.G. (1991). Agronomy and crop physiology of fibre hemp. A literature review. Centre for Agrobiological Research (CABO-DLO) Wageningen, The Netherlands.

Van der Werf H.M.G. (1994). Hemp facts and hemp fiction. Journal of the International Hemp Association, Vol.1, No.2.

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