Ch 3. Crop Protection Flashcards
What is a monoculture?
The expansion of land devoted to single crops and year to year production of the same crop species on the same land.
What 3 factors reduce the sustainability of monocultures in agriculture?
- Weed Competitors
- Pest Populations
- Diseases
What is a weed?
An unwanted plant in a human-controlled setting i.e. farm fields and gardens.
What is an Annual weed?
A weed which grows from seed and disperses its seeds in one year.
What 4 properties make Annual weeds successful?
- Rapid Growth
- Short life cycle
- High seed output
- Long-term seed viability
Give two examples of Annual weeds.
- Chickweed.
2. Speedwell.
What is a Perennial weed?
A weed that lives for more than 2 years, will generally die back over winter and grow in spring.
What 3 properties make Perennial weeds successful?
- Storage
- Vegetative Reproduction
- Rhizomes
Give two examples of Perennial weeds.
- Dandelion
2. Bramble
Why are Annual weeds particularly problematic in cultivated areas of farmland?
Because the constant tilling of the soil unearths seeds that germinate and grow quickly.
Why are Storage Organs useful to Perennial weeds?
Because they provide food for the weeds when rates of photosynthesis are low.
What is Vegetative production?
A feature which some Perennial weeds possess, which means they have reproductive structures such as bulbs and tubers which new plants can grow from.
What makes Perennial weeds most compatible with crop plants?
They are already well established in the area the crop is being planted.
Name 3 different types of Invertebrate Pests to crops.
- Insects
- Nematode worms
- Molluscs
How do insects cause damage to plants?
By feeding on them.
How do Nematode worms cause harm to plants?
They are found in the soil and attack plants root systems.
How do molluscs cause harm to plants?
By eating them.
Give two examples of molluscs.
Snails
Slugs.
How do these pest invertebrates reduce crop yield?
Damage caused to leaves can reduce the rate of photosynthesis and therefore reduce crop yield.
What 3 things can plant diseases be caused by?
- Fungi
- Bacteria
- Viruses
How do Invertebrate pests cause disease?
They often act as vectors, facilitating the spread of disease caused by microorganisms.
How does disease reduce crop yeild?
Because a proportion of the diseased crop plant may be unmarketable due to its appearance.
Name a disease to tomatoes which reduces crop yield.
Bacterial speck disease.
What is Bacterial speck disease caused by?
A bacterium called Pseudomonas syringae.