Industrial Hemp Cultivation in the Tropics

by Karin Westdyk

Originally published in the Belize Ag Report, March 2018

hemp.growing
Industrial Hemp Cultivation

marijuana.field
Marijuana Cultivation


It is important to understand the differences between industrial hemp and marijuana.
Technically, industrial hemp and marijuana are from the same plant genus: cannabis. However,
the genetics of industrial hemp and marijuana have evolved from different subspecies and there
are many important chemical and physical differences.

Chemically, marijuana typically contains between five and twenty percent tetrahydrocannabinol
(THC), while industrial hemp contains only about one-tenth of that. Most THC is formed in the
resin glands called trichomes on the flowers of the female plant. These glandular trichomes
produce and store large amounts of cannabis resin and the female plants are particularly rich in
glandular trichomes. Unlike marijuana, industrial hemp is not cultivated to encourage high
levels of THC, and therefore lacks the primary component that would make it psychoactive.
Therefore, when growing, the plants have a distinctly different appearance; this single difference
in the chemical make-up is what most people rely on to distinguish industrial hemp from
marijuana. For example, in Canada, where hemp comprises a growing part of the agricultural
economy (over 90,000 acres planted with retail sales close to $40 million), there is a maximum
THC content of industrial hemp at 0.3%. Cannabis with higher levels of THC is considered
marijuana instead. Canada also maintains an online list of the names of seeds that produce
plants acceptably low in THC, many of which are no longer even checked for THC levels as they
have proven to be consistently low.

There are other distinguishing factors as well. Industrial hemp has a much stronger fiber; the
cellulose and hurds can be used in making rope, paper, building materials, fuel, and plastic.
Marijuana fiber is weaker and breaks easily, making it a poor fibrous plant when compared to
industrial hemp.

One of the main differences is in how the two are cultivated. Industrial hemp is tall and spindly
growing tightly compacted with 30 to 40 plants per square foot and reaching 6-15 feet in height,
while THC-producing marijuana plants are grown to an average of only 4-5 feet and are far more
spread out. The cultivation of psychoactive marijuana also requires a great deal more attention
since the objective is to encourage the plant’s flowers to produce more psychoactive THC
containing resin. Once the male plants declare, they are generally removed in order for the
female plants to pump out more THC resin awaiting pollination. These also produce few if any
seeds as a result of male plant pollinator removal. On the other hand, since the hardy parts of
industrial hemp are the most desired, along with the seeds, both male and female plants are
used producing a higher crop yield with many seeds that can be made into biofuel and/or a
highly nutritious food. Industrial hemp plants have very little potential to produce high-content
THC and when pollinated by members of their own subspecies, their genetics remain similar,
i.e., with continued low levels of THC.

Industrial hemp can be grown in a wider range of soils than can marijuana; it grows on marginal
land not suited for growing food crops. Depending on where and how it is grown, industrial
hemp requires little-to-no fertilizers or pesticides and the most effective pesticides can be
derived from organic sources such as neem oil. Ideally, and initially, industrial hemp could be
grown on fields that provide high yields for corn, which is why it makes a perfect rotation crop --
choking out weeds, eliminating the need for toxic, expensive herbicides and pesticides, cleaning
the soil from previous use of agrochemical poisons, while providing an excellent amendment to
the soil -- replacing organic matter and, with its extensive root system, aerating the soil that will
nurture the corn.

Depending mostly on the climate, sown seeds produce plants that can be harvested within 70 to
140 days. According to the Agricultural Marketing and Resource Center, a U.S. information
resource for value-added agriculture, “One acre of hemp can yield an average of 700 pounds of
grain, which in turn can be pressed into about 22 gallons of oil and 530 pounds of meal. The
same acre will also produce an average of 5,300 pounds of straw, which can be transformed into
approximately 1,300 pounds of fiber.” The fiber can be used for rope, fabric, paper, cellulosic
fuel, and/or building materials.

Those concerned about growing marijuana within industrial hemp crops can be assured that
since industrial hemp is grown tightly together and is very tall and thin, any THC-producing
marijuana would stand out like a sore thumb and would not thrive. Its wide growth would
require a large amount of space in order to get adequate sunlight from beyond the tops of the
taller competing industrial hemp plants.

Considering the fact that hemp is one of the most versatile and adaptable plants on earth and
grows and thrives just about anywhere, growing hemp in the tropics could present a unique set
of opportunities as well as challenges. Special cultivars for producing either seed or fiber or a
combination of both are needed as well as seeds that will grow well in a tropical climate.
Temperate cannabis seeds grow plants that depend on certain light conditions. The shorter days
in the tropics will cause them to quickly mature and flower, going into reproductive mode too
early. Another challenge is moisture during the rainy season; mold-resistant plants would be
best in the tropics. The success of industrial hemp in the tropics depends largely on the origin of
the seed. Latitude, day length and humidity are all factors to consider when choosing the best
seeds.

A successful tropical industrial hemp project conducted at the University of Hawaii initially used
3 different cultivars and found that the temperate zone seeds did not do well, but the tropical
seed hemp and tropical fiber hemp flourished. It demonstrated that the best tropical strains
were sativa plants (as opposed to indica or ruderalis varieties) evolving from Thailand,
Cambodia, Mexico, Jamaica or Colombia, as sativas grow taller with lots of space between the
leaves allowing for better air ventilation to help avoid mold.

An initiative to foster research and education has been established in Belize to support
agricultural practices and choices that do no harm. Industrial Hemp Education and Research
Association of Belize has a website to gather and research information on growing industrial
hemp in Belize. It is believed that industrial hemp could transform the economy of Belize in
positive and beneficial ways, and therefore should be explored to its full potential. The website is
www.hempbelize.org.

Since industrial hemp is so different from high-THC marijuana, it makes perfect sense that its
cultivation be fostered in Belize. Nutritionally, hemp seeds provide the highest form of amino
acids in the plant world, and is second only to soy in protein. Organizations and churches
interested in alleviating world hunger or in preparing for a future food shortage are working to
develop a highly nutritious and abundant food combining moringa with hemp seed. The
education of children has proven to be greatly improved when children’s bodies and minds are
nourished with good nutrition. Those interested in clean renewable energy and the
environment place hemp at the top of the chart in biofuels, rating it the best biofuel Mother
Earth can produce as it is carbon neutral, will grow on marginal land, needs no-to-minimal
fertilizer or pesticides, can be harvested 2-3 times a year, and can produce fuel from both the
seed and cellulose.

Economically, industrial hemp could greatly boost the economy in Belize as it has done
everywhere it is grown, producing jobs in cultivation, processing, and marketing. A press release
issued in the spring of 2017 by Vote Hemp, a US-based non-profit organization dedicated to
advancing a free market for industrial hemp, low-THC oilseed and fiber varieties of cannabis,
reported that annual retail sales in 2016 for hemp products were $688 million in the US alone
from just food, body care products, medicines, and supplements with a 25% growth from the
previous year.