3.3 Flashcards
What do weeds do to crop plants
Compete
What do pests and disease do to crop plants
Damage them and reduce productivity
Annual weeds?
Rapid growth
Short life cycle
High seed output
Long term seed viability
Perennial weeds
Storage organs and vegetative reproduction
How can weeds,pests and disease be controlled
Cultural and chemical means
Selective herbicide
Have a greater effect on certain plant species
Broad leaves weeds
Systemic herbicide
Spread through vascular system and prevents regrowth
Problems with pesticides
Bioaccumulation
Biomagnification
Persistence in environment
Toxic to non target species
What is bioaccumulation
Build up of chemical in an organism
Biomagnification?
Increase in concentration of chemical between trophies levels
What is more affective than treating diseased crops
Application of fungicide based on disease forecasting
How else can weeds pests and disease be controlled
BC or integrated pest management
What is IPM
Combination of chemical, biological and cultural means
Risks of biological control
The control organisms may become an invasive species
Why is intense farming less ethical than free range
Poorer animal welfare
