Transcript Topic 3 - mrhebert.org

TOPIC 3
Plant Reproduction and Breeding
BREEDING
Selective Breeding: People choose specific plants with specific
characteristics and encourage these plants to
reproduce
- Canola was made by the selective breeding of rapeseed
Genes: The part of the cell that controls
plants’ characteristics (DNA)
TYPES OF REPRODUCTION
Sexual: Involves the specialized seeds and fruits of two plants.
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TYPES OF REPRODUCTION
Asexual/vegetative reproduction : Occurs when a parent plant
grows plants from its roots, stems, or leaves.
-E.g. Grafting – taking the branch of one tree and attaching it to another.
SEED PLANT
REPRODUCTION
Cones: The part of the tree that has a series of wooden scales.
Female cones contain ovules (eggs); Pollen grains containing sperm
develop on the smaller male cone. When the two meet the sperm swims
down the pollen tube and fertilizes the egg.
Pollination: The process of pollen traveling to the female cone.
FLOWERS
A flower’s main job is to attract insects that will spread the plant
pollen to other plants.
PARTS OF A FLOWER
Stamen: Male part of the flower
Pistil: Female part of the flower
Petals: Usually brightly coloured
Sepals: Green parts found underneath the flower.
The pistil has 3 main parts…
Stigma: Sticky tip of the pistil that catches pollen
Style: The tube connecting the stigma and the ovary
Ovary: A tiny chamber that holds the ovule (eggs)
CONTINUED
The Stamen has 2 parts…
Filament: The stalk
Anther: The tip
produces the pollen
PARTS OF THE FLOWER
SEED TO FRUIT
Once a plant is pollinated a seed is formed, inside the seed is a
tiny living plant called an embryo which is surrounded by food to
keep it alive.
Fruit: A growing ovary of a plant, which swells and protects the
seeds until they are ripe.
POLLINATION 3 STEPS
1) Pollen grain lands on the stigma
2) A pollen tube grows down the style into the ovary and enters
an ovule
3) A sperm travels down the tube to fertilize the egg.
PATHWAY FROM POLLINATION
TO GERMINATION
HOW SEEDS ARE
DISPERSED
- Animal Transportation
- Caught in fur
- In their droppings
- Insects
- Bees spread pollen
- Humans
- Throwing seeds
- Caught on clothes
- Heat Exposure
- Trees burn down launch seeds
- Cones explode under heat
- Wind
- Blows pollen around
- Blow spores and/or seeds
- Water
- Seeds / cones fall in water and
swept to other fertile locations
Germination: The development of a seed into a new plant
TOPIC 4
Meeting the Need for Food & Fibre
AGRICULTURE
Canada is one of the
leading exporters of
food and fibre in the
world.
Sustainability…
Being able to grow
food and fibre
while keeping our
natural systems healthy
for long term.
CROPS IN ALBERTA
Wheat: Ground up for flour
Barley: Fed to livestock, Used for making malt
Oats: Mostly fed to livestock some for breakfast cereals
Legumes: Such as peas and lentils, all high in protein.
Canola: Used to make margarine, salad dressing, vegetable oil, etc.
Potatoes: French fries, potato chips
Alfalfa: Feeds livestock, strong root system
Specialty Crops: Ginseng, beans, sunflowers and spices
CROPS IN ALBERTA
Wheat
Barley
Oats
Legumes
Canola
Potatoes
Alfalfa
Name That Crop!
FARMING PRACTICES
Irrigation: Watering crops using a system of large pipes and sprinklers.
Monoculture: Growing only one type of plant in the field for greater efficiency
GREENHOUSES
What are the disadvantages and advantages of greenhouses?
Pros
- You can control all variables
- Water
- Wind
- Temperature
- Soil (sort of…)
Both
- It can keep bugs out
which is good for
limiting pesticide use
however you cannot
have the It
pollen or seeds
spread naturally because
of it
Cons
- It can be very expensive
- You cannot grow all
crops / plants in any
greenhouse
FORESTRY
Forestry in a major industry in Canada.
Diversity: Variety of plants and animals in an ecosystem.
How many different trees can you think of ??
COMMON TREES FOUND
IN ALBERTA
Lodgepole Pine: Largely used in construction.
White Spruce: Used in plywood, pulp and paper
Black Spruce: Lumber and strong paper
Aspen: Good for furniture, pulp and paper
White Birch: Furniture and firewood
Tamarack (Larch): Has a fungus that resists decay, so it is used on fence posts and
railway ties.
STEPS IN HARVESTING TREES
1) Planning the cut
(based on careful
review of the site)
2) Building a road into the area
3) Felling and delimbing trees
4) Dragging the logs to a central
loading point
5) Hauling the logs to a sawmill
6) Preparing the site for reforestation
7) Reforestation
GLOBAL PROBLEMS
Erosion: Soil that is blown away by wind and water.
- Is that it?
Human Activity!
Desertification: As a result of drought, desert takes over
agricultural land.
TOPIC 5
Sustaining The Soil
TOPIC 5: SUSTAINING
THE SOIL
Developing Soils – 5 main factors that affect how soil develops.
1)
Parent material: piece of matter (non-organic) formed by layers of rock, soil,
clay and sand
2)
Vegetation: determines the amount and type of organic matter in, and on, the
soil
3)
Landscape: a healthy area that has a healthy balance of water and nutrients
4)
Climate: determines what kind of plants will grow and how fast they will
decompose
5)
Time: all of these processes happen over time so they occur at different paces
in different places
SOIL CONTINUED…
Humus: A dark soil rich in nutrients and holds water well.
Healthy soil needs decomposers to break down dead organisms so
plants can use the nutrients. There are 4 key types, which work
differently…
1) Bacteria – actively break down dead material
2) Fungi – make nutrients available to plants
3) Microscopic actinomycetes - special kind of bacteria that help
to create humus
4) Earthworms – Grind, digest and mix soil
HEALTHY PLANTS
Healthy plants require six nutrients
1)
Nitrogen
2)
Sulfur
3)
Phosphorous
4)
Calcium
5)
Potassium
6)
Magnesium
CHALLENGES AND SOLUTIONS
Salty Soil: Caused by too little vegetation and too much water (salinization)
Solution??
Replant areas so the water can’t dissolve the salt and leave it behind
Soil Erosion: Caused by too much cultivating mixed with water and wind
Solution??
Leaving a root system in place to hold the dirt, shelter belts, crop rotation
HOW DO WE SAVE SOIL
• Different ways of preparing fields
• Using “Seed Drills”
• Using “Wide Shovel Cultivators”
• Being Shelterbelts
(Rows of trees that surround crops to protect from wind, encourage
wildlife and retain moisutre)
• Reshape and seed waterays
HYDROPONIC TECHNOLOGY
Growing plants without dirt!
Hydroponics is a subset of hydroculture and is a method of
growing plants using mineral nutrient solutions, in water, without soil. Terrestrial
plants may be grown with their roots in the mineral nutrient solution only or in
an inert medium, such as perlite, gravel, mineral wool, expanded clay pebbles or
coconut husk.
Seems good but any cons?
High energy cost!!
High initial start up cost!!
TOPIC 6: PESTS AND PEST
CONTROL
Pest: Any organism that humans find annoying or harmful.
Dandelions – the most successful plant pest, here’s why…
1) Powerful roots
2) Broad leaves
3) Super seeds
4) Adaptable
5) Chemical weapons
PESTS
• In normal systems there are pests
• - Insects
- Typically eat crops
• - Fungi
- Cause infections / disease in plants
• - Weedy Plants
- Steal moisture/nutrients/space
• Pests consume, on average, over 50% of Canada’s annual harvest
• Farmers spend millions on eliminating & controlling them
INTRODUCED SPECIES
Introduced Species: Species not common to an area (often with no
natural enemies)
Pests were controlled by herbicides, insecticides, fungicides, and a
bunch of other “cides”. Problems are associated with all of these
chemicals
E.g. Bioaccumulation, and poisoning “innocent” species.
On top of this, some pests are becoming resistant to chemicals
Biological Control: introducing a pest’s natural enemy to control it
What are introduced species to Canada?
ORGANIC FOOD
Organic Food: Food grown without the use of pesticides or
chemical fertilizers.
The need for chemicals is reduced by:
1) Sowing good quality seeds
2) Removing weeds early
3) Cutting weeds along property edges
4) Cleaning equipment so that it doesn’t transfer weeds
5) Using biological control