3.3 Crop protection Flashcards
Weeds..
Compete with crop plants, while other pests and diseases damage crop plants, all of which reduce productivity.
What are properties of annual weeds?
Rapid growth, short lifecycle, high seed output and long-term seed viability
What are properties of perennial weeds with competitive advantages?
Storage organs and vegetative reproduction
Most of the pests of crop plants are..
Invertebrate animals such as insects, nematode
worms and molluscs
Plant diseases can be caused by..
Fungi, bacteria or viruses, which are often carried by invertebrates
Control of weeds, other pests and diseases by cultural methods
Ploughing, weeding and crop rotation
Pesticides include..
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
Describe selective herbicides
Have a greater effect on certain plant species (broad
leaved weeds)
Describe systemic herbicides
Spreads through vascular system of plant and
prevents regrowth
Systemic insecticides, molluscicides and nematicides..
Spread through the vascular system of plants and kill pests feeding on plants
Problems with pesticides
Toxicity to non-target species, persistence in the environment, bioaccumulation or biomagnification in food chains, producing resistant populations of pests
What is more effective than treating diseased crops
Applications of fungicide based on disease forecasts
What is bioaccumulation?
Bioaccumulation is a build-up of a chemical in an organism
What is biomagnification?
Biomagnification is an increase in the concentration of a chemical moving between trophic levels
Biological control
In biological control the control agent is a natural predator, parasite or pathogen of the pest
