Decimal code for growth stages of Cannabis sativa L.

A Four Digit decimal code indicating growth stages ( and few more characteristics ) of Cannabis Sativa L.

Practical use of a code for fibre hemp growth stages

Depending on the use of the hemp crop, harvest time has an important effect on yield and
quality of hemp products. For best fibre quality, harvest should be carried out during male
flowering (code 2102) or during flowering of monoecious crops (code 2302; Bócsa and
Karus 1997). Unfortunately, the European Union states that hemp harvesting - independent
of utilisation - has to start after seed formation, i.e. code 2204 or 2306 (Hennink 1997,
European Union 199. This stage is the best time for seed harvest (Bócsa and Karus 1997).
For the production of essential oil, the recommended stage is one to three weeks before
seed maturity (codes 2203 and 2305; Meier and Mediavilla 199. At this time the highest
level of the secondary compounds (e.g., volatile compounds) is reached.
Another practical use of growth stages is fertilisation. In contrast to the custom in most
countries, where all fertiliser are given at planting, Mediavilla
et al.(199, recommends for Switzerland to split the nitrogen fertilisation in order to reduce nitrogen loss. One rate is given at the emergence (code 0002) and the second rate when the third leaf pair has been
formed (code 1006). For the determination of the cannabinoid content, in accordance with other authors,
the inflorescences were collected at the beginning of the seed maturity (code 2203 and 2305; de
Meijeret al.1992). The appearance of diseases can be easily described by using a decimal
code (McPartland 1996a, 1996b). For computer storage of data referring to the development
of plant populations, e. g. for growth analysis, the decimal code is very useful.

Click to expand...

Notes:

a) In contrast to the subsequent leaves, cotyledons are sessile and have
no serrate margin.

b ) We consider a leaf as unfolded when its leaflets are at
least one ( 1 ) cm long.

c ) The change of phyllotaxis (leaf position) from opposite
to alternate, indicates the induction of flowering
( „GV point“/ code 2000 ) ; Bócsa and Karus ,1997).


1st digit denotes 'Principal Growth Stage " .

0 = Germination & emergence
1 = Vegetative growth stage
2 = Reproductive stage ( Flowering & Seed Production )
3 = Senescence


2nd digit denotes "gender" ( Dioecious/Monoecious )

0 = not shown / not known
1 = male (staminate)
2 = female (pistillate )
3 =Monoecious / Hermaphrodite

3rd & 4th digit denote growth stage .



http://www.inaro.de/deutsch/kulturpf/hanf/hemp_key.pdf

0000 = Dry seed
0001 = Radicle apparent
0002 = Emergence of hypocotyl
0003 = Cotyledons unfolded

1000 = Cotyledons fully unfolded ,1st pair of true leaves under 1cm
1002 = 1st leaf pair ( 1 leaflet / blade )
1004 = 2nd leaf pair ( 3 leaflets / blades )
1006 = 3rd leaf pair ( 5 leaflets / blades )
1008 = 4th leaf pair ( 7 leaflets / blades )
1010 = 5th leaf pair ( 7/9 leaflets / blades )
.....
10xx = nth leaf pair ( xx= 2n )


2000 =GV point / induction of flowering
2001 = Flower primordia

(female sensimilla )

2200 = Flower formation
2201`= Beginning of flowering (Styles of first flowers)
2202 = Flowering ,50% of bracts formed
2212 = End of Flowering ,buds swelling ,95% of bracts formed
2222 = Harvest time

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(female pollinated)

2203 = Beginning of seed maturity ,first seeds harden.
2204 = Seed maturity 50% of seeds hard.
2205 = End of seed maturity 95% of seeds hard

(female end of cycle)

3201 = Leaf desiccation
3202 = Stem desiccation
3203 = Stem decomposition


Cheers.