This document discusses the relationship between humans and plants. It begins by identifying coffee plants and their origins in Africa. It then discusses how coffee plantations have damaged environments by clearing large areas of land for monocultures. This makes the crops more susceptible to pests, requiring pest control methods like mechanical, biological, and chemical approaches. The document also discusses hydroponic and aeroponic culturing as alternatives to traditional farming. It outlines how fertilizers supply nutrients to plants but can damage them if overused. Finally, it lists several uses of plants for humans, such as for food, medicine, clothing, building materials, and aesthetics.

1. PLANTS & US

2. PLANTS & US
Identify this plant:

3. PLANTS & US
This is a coffee plant
-Coffee plants are
evergreen shrubs or
small trees that grow
in shaded areas
-Coffee “beans” are
actually the seeds of
coffee berries
-Coffee plants are
native to Africa

4. PLANTS & US
Coffee is the second
most-valuable-traded
commodity in the
world (second only to
petroleum)
Its demand has
resulted in the mass
development of coffee
plantations.

5. PLANTS & US
Coffee plantations:
-Damage the environment
(and animal habitats)
through the mass clearing
of land in order to create
plantations
-Are monocultures, which
lack diversity and are more
susceptible to disease and
pests
-As a result, a number of
pest control methods are
necessary to protect the
crops

6. PLANTS & US
Pest control:
Mechanical
control
-physically
trapping pests
PEST CONTROL

7. PLANTS & US
Pest control:
Crop rotation and
mixed planting
-When farmers do not
grow monocultures in
the same location year
after year, pest
populations do not have
the same opportunities
to establish and prosper
PEST CONTROL

8. PLANTS & US
Pest control:
Crop rotation and
mixed planting
PEST CONTROL

9. PLANTS & US
Pest control:
Biological control
-Predatory insects,
mites, and disease-
causing micro-organisms
prey on and infect pest
species
(i.e. parasitic wasps and
lady bugs)
PEST CONTROL

10. PLANTS & US
Pest control:
Baiting pest
-Pheromone baits can be
used to confuse mating
insects
-can be used for trapping
too
PEST CONTROL

11. PLANTS & US
Pest control:
Chemical control
- Using chemicals (i.e.
pesticides) to remove
pests
PEST CONTROL

12. PLANTS & US
Pest control:
Chemical control -
Pesticides
-Can be dangerous to non-pest
organisms (including beneficial
organisms) and humans
-Overuse or improper use can
lead to pesticide resistance
PEST CONTROL

13. PLANTS & US
Pest control can also be managed through growing plants
without relying on fields and soil
Hydroponic culturing
-Growing plants on mineral nutrient solutions without soil
PEST CONTROL

14. PLANTS & US
Advantages:
-No soil is needed
-The water stays in the system and
can be reused- thus, lower water
costs
-It is possible to control the
nutrition levels in their entirety-
thus, lower nutrition costs
-Stable and high yields
-Pests and diseases are easier to
eliminate than in soil because of
the container's mobility
PEST CONTROL

15. PLANTS & US
Disadvantages:
-Creates an environment which
encourages salmonella bacteria
growth
-Some plants cannot grow
effectively (and may begin to wilt)
due to the constant high moisture
levels
-Gases do not dissolve very well in
the water solution, so gas
exchange where the plants contact
water is limited
PEST CONTROL

16. PLANTS & US
Aeroponic culturing
-roots are continuously
or discontinuously kept
in an environment
saturated with fine drops
(a mist or aerosol) of
nutrient solution
-More plant species can
grow with this method
because water exposure
is catered to the needs of
the plant, and air can
reach more parts of the
plant
PEST CONTROL

17. PLANTS & US
To maximize crop yields,
farmers often rely on
fertilizers.
Fertilizers
-supply plants with
nutrients
-focuses on 3
macronutrients for plants:
Nitrogen (N)
Phosphorus (P)
Potassium (K)
Fertilizers

18. PLANTS & US
Fertilizers
-the overuse of fertilizers
can result in the drying of
roots and damage to the
plant
-plants that have received
too much fertilizer exhibit
“fertilizer burn”
Fertilizers

19. PLANTS & US
Aside from coffee,
humans use plants for
many other purposes:
Food
Cereals, fruits &
veggies, food for
livestock
Medicine
Taxol, Aspirin,
Morphine
Clothing
Cotton, linen, hemp
Building material
Wood
Fuel

20. PLANTS & US
Plants as Food

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Plants as Medicine
Some plants contain
chemicals that protect the
plant by partially
debilitating the herbivores
that ate them.
These chemicals are
psychotropic (they alter
perception, emotion, or
behaviour).
Ex. Marijuana contains
tetrahydrocannabinol
(THC) which has been used
in medicine to increase
appetite, decrease nausea,
and reduce muscle spasms

22. PLANTS & US
Plants for Clothing
Cotton Hemp

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Plants for Buildings

24. PLANTS & US
Plants for Fuel

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More uses:
Aesthetics

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More uses:
Fragrances

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More uses:
Gardens

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More uses:
Gardens:
Plants have tropisms that
enable gardeners to achieve
various “looks” for their
garden
Tropism = A directional
growth response to unequal
stimulation from the
external environment.

29. PLANTS & US
Phototropism:
Light affects the growth of
the plant
The parts of the plant that
are positively phototrophic
are the leaves and stems
The parts that are
negatively phototrophic are
the roots.
Auxin allows the cells on the
shaded side of the plant to
grow and elongate. This
causes the plant to lean
towards the light source.

30. PLANTS & US
Gravitropism:
Gravity affects the growth of
plants.
Roots are positively
gravitropic
Stems and leaves are
negatively gravitropic (they
tend to grow in a direction
against gravity)

31. PLANTS & US
Thigmotropism:
Plants that are affected by touch and
contact.
Vines are examples of thigmotropism.
They coil around each other.