Topic 3: Crop Protection Flashcards
What do weeds compete with?
Crop plants
What do pests and diseases damage and why is it bad?
Leaves of crop plants reducing productivity
What are the characteristics of annual weeds?
Rapid growth,
short life-cycle,
high seed output,
long-term seed viability
What is the competitive adaptation of perennial weeds?
Storage organs, vegetative reproduction
What is the category most pests of crop plants arise from?
Invertebrate animals such as; insects, nematode worms, molluscs
Plant disease can be caused by what?
Fungi, bacteria, viruses
Plant diseases are often carried by what ‘thing’?
Invertibrates
What are some cultural methods to control weeds, pests and diseases?
Ploughing, weeding and crop rotation
What are the names of some pesticides?
Herbicides, fungicides, insecticides, molluscicides, nematicides
What is the function of a herbicide?
To kill weeds
What is the function of a fungicide?
Control fungal diseases
What is the function of an insecticide?
Kill insect pests
What is the function of a molluscicide?
Kill mollusc pests
What is the function of a nematicide?
Kill nematode pests
Pesticides can be of two categories, what are they?
Selective or systemic
What is a selective herbicide?
Have a greater effect on certain plant species (broadleaved weeds),
Mimic the action of natural plant growth substances to stimulate the rate of growth
What is a systemic herbicide?
Spreads through vascular system (transport system) of plant and prevents regrowth
How do you systemic insecticides, molluscicides and nematicides function?
Spread through the vascular system of plants and kill pests feeding on plants
How are fungicides best used?
Based on DISEASE FORECASTS rather than trying to treat already diseased crops
Why can spraying diseased crops with pesticides be wasteful?
It is better to use disease forecasting to predict a fungal outbreak and spray before disease spreads
What are some problems included with the use of pesticides?
They may be toxic to non-target species,
persistent in environment,
biomagnification,
bioaccumulation,
production of a resistant population of pests
What is bioaccumulation?
The buildup of a chemical in an organism
What is biomagnification in a food chain?
An increase in the concentration of a chemical moving between trophic levels
How can weeds, other pests and diseases be controlled?
By biological control and integrated pest management (IPM)
what does Integrated pest management (IPM) include?
combines chemical, biological and cultural control
What does biological control involve the use of?
A natural predator, parasite or pathogen of the pest
What are the risks with biological control?
- Control organism may become an invasive species
- May parasitise, prey on or become a pathogen of other species
