Lecture 7 Flashcards
What is a plant stress?
Anything that prevents a plant from growing to its full potential
Abiotic stress is caused by
a non-living organism
examples of an abiotic stress
salt, temperature, and nutrients.
stresses by salts
salts in soils deprive plants of water and dissolve nutrients
Low temperature plant stress
Lower temperatures will result in slow plant growth and development.
Where is winter burn particularly noticeable?
Evergreen species.
High temperature plant stress
Damage plant tissue. the cell proteins coagulate and plant cell dies.
Wilting
When plants are unable to take up moisture, they will eventually die because the N.A.R is negative.
What is a stomata?
Openings in plant that allow for movement of gases. E.g., photosynthesis and respiration.
What do guard cells respond to in order to regulate the opening?
turgor pressure.
Trichomes
Hairs. May be unicellular or multicellular.
What is a biotic stress?
A stress to a plant caused by a living organism.
What are weeds?
Any plant that is growing in a place where it is not wanted.
Harvest loss caused by weeds
May occur if the weeds are so thick that harvesting is difficult.
toxic weeds
Death cama’s
Why are weeds a problem?
Weeds are hard to control because they are very suited to their environment.
Rhizomes
Horizontal underground stems
Seeds and fruits can be distributed in several ways, such as:
- ) wind adaptations.
- ) Water
- ) Animals
The disease cycle is broken in to a number of stages
- ) Inoculation
- ) Incubation
- ) Infection
Causes of Infectious Disease
Caused by micro-organism which attack susceptible plants.
What is the most common (and important) plant disease causing organism in Western Canada?
Fungi
How does Fungi reproduce?
Spores. spreader by wind, water, machinery, animals, insects, contaminated seed, etc.
What do plant disease cause?
Yield loss and quality loss.
Sclerotinia
Sclerotinia stem rot, commonly known as white mould, is caused
by the fungus Sclerotinia sclerotiorum.
What is an Ergot?
A fungal pathogen that creates sclerotia as overwintering bodies.
Aster Yellows
A disease caused by phytoplasma that results in phyllode and is transmitted by leaf hoppers.
2 groups of insects
- ) beneficial insects
2. ) Harmful insects
Beneficial Insects
Perfect duties advantageous to humans.
Harmful Insects
damage to crops, food, buildings, etc.
Insect damage. extent of damage depends and how well the plant recovers is dependent on:
- ) insect population.
- ) Plant growth stage.
- ) growing conditions.
- ) Weather.
Who suffers the most from insect damage?
Smaller plants
the Cyclical Nature
Damage occurs in a cycle related to life cycle of insect.
