Agriculture Reference
In-Depth Information
3 m
height
of crop
fibre maturity
end of flowering =
end of growth
HARVEST
2 m
fibre and seed
maturity
FLOWERING
1 m
early variety
SOWING
EMERGENCE
late variety
beginning of phase of active growth
May
June
September
July
August
Fig. 5.2.
Growth of hemp. Example of a crop sown in early May showing growth of an early and a late
developing variety.
14
Phase 2: rapid growth
Phase 3: slow growth
Phase 1: slow growth
12
y = -0.0145x
2
+ 0.4893x + 2.7181
R
2
= 0.7288
10
8
6
4
2
0
Dates
Fig. 5.3.
Daily growth rates for hemp. ADG = average daily gain in height (FDGEDA de l'Aube, 1999).
5.2.3
Absorption of organic elements
and minerals by hemp
cytoplasm of cells and plays an important role
in plant metabolism. This element is obtained,
in its mineral form, from the soil.
Nitrogen has a significant influence on
plant growth. It is found in particular in young
plant tissues and in certain storage tissues. It
promotes the development of the stem and
leaves, which become dark green as a result
of their high chlorophyll content (a molecule
high in nitrogen). The green parts of the plant
allow carbon to be assimilated into the plant
The breakdown of mature hemp plants into
constituent organic compounds and minerals is
presented in Table 5.2.
Nitrogen
All plants contain a certain amount of
nitrogen. It is an essential constituent of the
