Maximum Yield Australia/New Zealand May/June 2019 | Page 60

CULTIVATION DIFFERENCES
“BESIDES HAVING different
levels of THC, hemp and
marijuana are grown differently
for different market purposes.”
BOTANICAL DIFFERENCES
Botanically, most biologists consider hemp and
marijuana to be varieties of the same species
(Cannabis sativa). So, how can two plants that are
almost genetically identical be so different in function
and form? Think of the differences in dogs. All dogs are
classified as Canis familiaris, but we have all seen the
great variation in their sizes, colours, and temperaments.
Though they are closely related and genetically similar
enough to cross breed, nobody is going to confuse a Great
Dane with a Chihuahua. Industrial hemp and marijuana
are no different; they are of the same genus and species
but have different characteristics.
Hemp leaves tend to be skinnier than marijuana’s
wider leaves. Hemp also tends to be a taller and
skinner plant, while marijuana grows fuller, fatter,
and shorter. Not to add even more confusion, but there
are similar physical differences between the different
marijuana types of sativa, indica, and ruderalis.
As noted above, the primary difference between
marijuana and hemp is in their chemical compositions.
Hemp, having little to no THC, tends to have high
levels of cannabidiol (CBD). The level of CBD, of course,
is not the main defining factor as sativa, indica, and
ruderalis marijuana strains can have varying degrees
of CBD in tandem with varying degrees of THC.
58
Maximum Yield
There is a wide gap between the cultivation methodolo-
gies for hemp and weed. Hemp crops can tolerate a wide
range of temperatures and are grown in many parts
of the world, whereas marijuana plants are usually
restricted to warmer climates. The typical growing
season for hemp crops is between 100 and 120 days.
Marijuana’s range is generally more like 60 to 90 days.
Industrial hemp plants are grown as close together
as 10 centimetres, often in large plots, with up to
50 plants per square foot. This dense planting
reduces branching and flowering, meaning
industrial hemp plants are typically grown as a
single main stalk with a few leaves and branches.
Hemp growers that wish to realise high yields grow
their plants tall. They can be towering, with some
species reaching heights of up to 4.5 metres. Hemp
is grown primarily for its two types of fibre: bast
and hurd. Bast is the outer portion of the hemp
stem and hurd is the pith, or interior fibre.
When cannabis is grown for marijuana, it is almost
always done with the intent to produce and harvest
the female flowers (and often the leaves). The female
flowers are short, clustered, and full of THC. So,
unlike with hemp cultivation, marijuana is cultivated
to encourage the plant to become bushy with wide
branches and heavily foliated to promote flowers
and buds. This requires that plants be well-spaced,
generally two to three metres apart, with no more than
two plants per square yard. That’s more than 200 times
more space than a single hemp plant is afforded.
It should be noted that growers who produce both
hemp and marijuana (or produce one crop near a
grower who produces the other) do so at their own
risk. Cannabis plants are open-, wind-, and insect-
pollinated, and hemp and marijuana are related
closely enough to cross breed (again, think of dog
species). Cross-pollination between the two crops
would spell disaster for the quality and intent of
either. It could reduce the desired psychoactive
effects of marijuana or render a hemp crop
illegal due to increased THC levels. Even the
cross-pollination of a hemp crop with inferior
hemp plants (or a marijuana crop with
inferior weed plants) is not desirable. Some
fibre and seed crops are valued based on
their purity and any dilution of that could
make a crop less marketable.
All these differences do not cover the full
spectrum of variations between industrial
hemp and marijuana, of which there are
thousands. This does not even consider
the scores of differences in legal opinion,
laws, ordinances, and other governance
pertaining to the differences between
the two crops, regardless of the
intended use and if based in science
or popular opinion. The bottom line is:
they are very closely related, but
are not the same plant.