3.3 Crop Protection Flashcards
what competes with crop plants?
weeds
what damages crop plants? (2)
pests and diseases
Characteristics of annual weeds (4)
- rapid growth
- short life cycle
- high seed output
- long term seed viability
characteristics of perennial weeds (2)
- storage organs (so the plant has food in all environmental conditions)
- vegetative production (can reproduce with methods other than seeds)
most of the pests to crop plants are…
invertebrate animals
examples of invertebrate animals (3)
- insects
- nematode worms
- molluscs
what are plant diseases often caused by? (3)
- fungi
- bacteria
- viruses
what are plant diseases often carried by?
insects
two main methods to control weeds, pests and diseases
- cultural control
- chemical control
methods of cultural control (3)
- ploughing
- weeding
- crop rotation
ploughing
buries perennial weeds
weeding
reduces competition with crop plants (should be done early in the crop’s life)
crop rotation
a series of different crops are grown on the same piece of land over time (current crop will not have the same pests and diseases as the last one)
types of pesticides (5)
- herbicides
- fungicides
- insecticides
- molluscicides
- nematicides
selective herbicides
have a great effect on certain plant species
systematic herbicides
spread through the vascular systems of plants and prevent regrowth
systematic insecticides
spread through the vascular systems of pests and kills them
the application of what is more effective than treating diseased crops
the application of fungicides based on disease forecasts
problems with pesticides (4)
- may be toxic to non-target species
- may persist in the environment
- may produce a resistant population of pests
- can cause/contribute to bioaccumulation/biomagnification
bioaccumulation
a buildup of chemical in an organism
biomagnification
an increase in the concentration of a chemical moving between trophic levels
biological control
when the control agent is a natural predator, parasite or pathogen of the pest you are trying to eliminate
integrated pest management
a combination of chemical, biological and cultural control
risks of biological control (3)
- the control organism may become an invasive species
- they may become a parasite
- they may prey on or become a pathogen of other species
