Fiber crops hemp & flax

Question 1

Cultivation of cotton - requirements, sowing and fertilization

Answer 1

Requirements:
- requires ample H2O supply
- needs warm temperatures

Sowing:
- February to June

Fertilization
- Requirements not very high

Question 2

Harvest of cotton

Answer 2

October to February
Yield would diminish in second year, replanted each year
Cultivation only in monocultures; therefore enormous pesticide requirements
Organic farming: <1% globally

Question 3

Hemp systematics

Answer 3

Cannabis sativa, Cannabaceae
Var. indica (indian hemp), gigantea (giant), ruderalis (wild)
Dioecic plant, annual

Question 4

Hemp products

Answer 4

Fibres, oil-rich seeds, THC
Traditional and very durable fibre for paper

Question 5

Origin of hemp

Answer 5

China, east Asia

Question 6

Dissemination - Hemp

Answer 6

Today mainly India & China
Banned in lots of countriees today because of high THC content of some cultivars

Question 7

Flax systematics

Answer 7

Linum usitatissimum, Linaceae
L. dehiscens (wild, annual to perennial), L. bienne (annual, overwintering)

Question 8

Products - flax

Answer 8

Fibres, oil-rich seeds
relatively soft and durable linen cloth was used for lots of purposes

Question 9

Flax origin

Answer 9

Fertile crescent

Question 10

Dissemination - flax

Answer 10

Europe, North America
Arrived in Switzerland ca. 6000 years ago

Question 11

Morphology of hemp

Answer 11

Tall (1.5 - 4 m) annual plant grown for grain and fiber

Leaves are palmate with 7 to 11 leaflets having serrated edges

Outer protion of stem contains strong bast fibers

inner portion of stem contains hurd, which is used for paper and buliding materials

Question 12

Stem cross sections

Answer 12

Page 6

Question 13

Hemp use

Answer 13

Page 9

Question 14

Why has hemp declined in the past 150 years?

Answer 14

Decreasing interest in hemp fibers and risk o addiction to THC as a drug

Question 15

Hemp cannabinoids

Answer 15

THC = hallucinogenic compound of Marihuana
only some cultivars above the allowed content of 0.3%

Cannabidiol (CBD) is closely related to THC but does not act hallucinogenic, reduces fear & inflammations

Question 16

Hemp seeds for animal and human nutrition

Answer 16

Contains a lot of unsaturated fatty acids
Flour can be used to make bread and other bakery products

Question 17

Fatty acid coposition of linseed oil

Answer 17

Linolenic acid 57%
Linoleic acid 16%
Oleic acid 19%
Other fatty acids

Linseed oil is richer than any other vegetable oil in essential fatty acids of the n-3 family & has good reputation for treating a range of ailments, from heart disease to autoimmune disorders

Question 18

Uses of linseed

Answer 18

Beeders - Seeds

Food industy - bakery products

Linseed cake
- pharmaceutical industry - medicinal plants
- feed industry - feeding stuff

Linsed oil
- Food industry - edible oil
- Lacquer and paints industry - special soaps
- chemical industry - paints, lacquer

Question 19

Advantages of flax fibres

Answer 19

fibers are twice as strong as those of cotton and 5x as strong as those of wool

Hygroscopic, able to absorb up to 12% of own wight in water

strength increases by 20% when wet

low stretching capability

good heat capacity

resistant to high temperatures (up to 300 °C)

Question 20

Disadvantages of flax fibres

Answer 20

Irregular fiber length and thickness

Separation of fiber from stalk tedious and relatively expensive

Question 21

Uses of fiber flax (whole plant)

Answer 21

Long fibres - 9% textile industry
Tow (short, broken fibers) - 7% paper and textile industry
Seeds - 11 % oil chemistry, food and feeding industry
Shives (shredded, woody remainders of the hurd - 45 % panel industry
Wax - 1% cosmetic and pharmaceutical industry

Question 22

Flax harvest

Answer 22

When leaves wither, stem turns yellow and seeds turn brown

stalk should not be cut in the harvesting process of fiber flax, but removed from ground intact

plants are pulled out of ground by hand or by machines

stalks are tied in bundles and traditionally left on field for two to eight weeks to allow retting by alternating wet and sunny conditions

Question 23

Harvesting and post-harvest steps - flax

Answer 23

Pulling up - no cut

Rippling - pass plant through coarse combs which remove seeds and leaves

Retting - woody bark is decomposed by water

Breaking - dry plants are sent through fluted rollers to break up stem and separate exterior fibers from bast, shives are scutched

Spinning - fibers are combed and straightened in preparation for spinning

Combing - further parallelization and purification of fibres

Question 24

Hemp processing

Answer 24

Similar as flax, but cut not pulled up

Dew retting
- harvested hemp is placed into windrows and left to desiccate until fungal organisms can complete the retting process in the stem
- requires usually only 1 to 2 weeks
- the fibres should turn golden or grayish in color and should sparate easily from the interior hurd
- stalks should have less than 15% moisture when baled and should be allowed to dry to 10% in storage out of the water

Water retting - by submerging the stems in water

Question 25

Biology of hemp

Answer 25

commonly dioecious plant, male and female plant

Male plant: earlier harvest or one has to live with finer fibres

female plant: strogner, taller, more biomass

Question 26

Linseed morphology differencies by use

Answer 26

Fiber flax:
- no basal branching
- plant height >= 100 cm
- use: fibers

Double purpose flax:
- little branching
- intermediate plant height
- use: fibers and oil

Linseed:
- strong branching
- low plant height
- use: oil

Question 27

Breeding of monoecious plants in hemp

Answer 27

Male flowers and female flowers are separated
yield of monoecious plants (biomass) is lower than yield of dioecious cultivars, but fibers are more homogeneous

Question 28

Flax plant flowers

Answer 28

May be blue or white

Flax plants with blue flowers yield the finest linen fibres

Flax flowering starts beginning of June

Flowering period can extend to several weeks

Question 29

Fruit - flax

Answer 29

Spherical capsules

Question 30

Optimal harvest point of linseed

Answer 30

Plants are desiccated and eeds rustle in the capsule