3.3 Flashcards
Describe weeds
. Compete with crops
.Unwanted and reduce productivity of crops
. Annual or perennial
Describe an annual weed
.Short one year
.Rapid growth
.large output of seeds
.Long term viability
Describe a perennial weed
Long several year life cycle
Vegetative reproduction
Storage organs
What are some cultural methods
Ploughing
Crop rotation
Biological control
Weeding
What is ploughing
.Turning and loosening top layer of soil and burries weeds
How does crop rotation a method to crop protection?
Growing different crops on the same land over several season thus decreasing diseases in one species of crops
How do systemic insecticides, molluscide and nematodes work?
Spread through vascular system of plants and kills pests that feed on the plant
What is important when using fungicides?
More effective to apply before the disease infects the plant
Name the problems with pesticides
.Toxic to non-target species
.Persistence in environment
.Bioaccumulation
.Biomagnification
.Production of resistant populations of pests
What is bioaccumulation
Build up of pesticides in one organism
What is Biomagnification
The increase of pesticide concentration between tropic levels i to the next in a food chain
What is a biological control
Introduction of a natural predator to the pest
What types of predator agents?
Parasite
Pathogen- disease causing microbe
What are the risks of a biological control
Becomes invasive and prey upon non-targeted species and causes harm to the environment
What is the combination of chemical, biological and cultural controls .
Integrated pest management
