crop protection Flashcards
What do weeds do to crop plants?
Weeds compete with crop plants.
What damages crop plants besides weeds?
Other pests and diseases damage crop plants.
What is the overall effect of weeds, pests, and diseases on crop plants?
All of these factors reduce productivity.
What are the properties of annual weeds?
Rapid growth, short life cycle, high seed output, and long-term seed viability.
What are the properties of perennial weeds with competitive adaptations?
Storage organs and vegetative reproduction.
What types of animals are most pests of crop plants?
Invertebrate animals such as insects, nematode worms, and mollusks.
What can cause plant diseases?
Fungi, bacteria, or viruses, often carried by invertebrates.
What are some cultural methods for controlling weeds, pests, and diseases?
Ploughing, weeding, and crop rotation.
What are the advantages of pesticides?
They can be selective or systemic.
What types of pesticides are there?
Herbicides to kill weeds, fungicides to control fungal diseases, insecticides to kill insect pests, molluscicides to kill mollusc pests, and nematicides to kill nematode pests.
What are problems associated with pesticides?
Toxicity to non-target species, persistence in the environment, bioaccumulation or biomagnification in food chains, and producing resistant populations of pests.
What is biological control?
Control of weeds, other pests, and diseases using natural predators, parasites, or pathogens.
What is integrated pest management?
A strategy that combines biological control with other pest control methods.
What is a selective herbicide?
A herbicide that has a greater effect on certain plant species, such as broad-leaved weeds.
What is a systemic herbicide?
A herbicide that spreads through the vascular system of a plant and prevents regrowth.
What do systemic insecticides, molluscicides, and nematicides do?
They spread through the vascular system of plants and kill pests feeding on the plants.
When are applications of fungicide most effective?
When based on disease forecasts rather than treating diseased crops.
What is bioaccumulation?
The build-up of a chemical in an organism.
What is biomagnification?
An increase in the concentration of a chemical moving between trophic levels.
What is integrated pest management?
Integrated pest management is a combination of chemical, biological, and cultural control.
What are the risks associated with biological control?
The control organism may become an invasive species, parasitise, prey on, or be a pathogen.
