Plant health Maintenance Flashcards
What is meant by physical control? And state 2 benefits and 2 limitations
Material, mechanical or hand control where weed or pest is directly blocked or destroyed.
Benefits
Remain in place for a long time e.g. Rabbit proof fencing.
Relatively little maintenance needed
Limitations
Expensive
Sterile soil may lead to worse spread of disease if introduced into it.
One example of a physical control and how risks to people and environment can be minimised.
Barriers - plastic membranes for reducing weeds but need to be disposed of properly and not burnt
Pheromone traps for luring pests
Rodent traps - care with children and pets.
What is meant by cultural control?
2 benefits
2 limitations
Cultural control is a procedure or manipulation of the growing environment. Gardeners in their everyday activities remove or reduce organisms in different ways and thus protect the crop.
Benefits - fit in naturally with daily routines
Can have long lasting effects such as removal of host weed.
No damage to environment
No damage to contamination of food crops
Limits - time consuming
Not Available for all pests
Many only available for glasshouses
Control may itself become a pest
What is meant by chemical control?
Name 2 benefits and limitations.
Use of chemical control to prevent or kill pest or disease
Benefits - rapid
Easily accessible
Limits - can be dangerous to humans animals and plants
Can cause resistant strains of pests and weeds to develop
Indiscriminate and can destroy beneficial predators
Examples of cultural control and risks and how to minimise
Increasing soil fertility. Addition of well composted material usually provides correct concentrations of nutrients to the plant. Risks to leaching into water courses leading to poor water quality and death of fish in intensively farmed areas.
Rotavating and crop rotation but some diseases last longer in soil than rotation cycle.
Harvesting and planting times
Companion planting
Examples of chemical control and risks
Herbicides - e.g. Glyphosate - may cause damage also to desirable plants and harmful to fish
Fungicides - Myclobutanil
Explain what is meant by biological control.
2 benefits
2 limitations
Use of natural enemies to reduce damage caused by pest
Benefits - Non toxic
Balanced population oF predators and parasites is reached.
No resistance build up
Limits - need to understand both the pest and predators life cycles and control carefully - timing crucial.
Only really effective in glasshouses
Any chemicals used against pest will also kill enemy.
Example of biological control
And risks
Slugs - nematodes
Whitefly - Encarsia Formosa
Explain the Importance of balance in horticultural situations.
Some practices disturb natural balances of predators and parasites.
It is important to encourage indigenous predators and parasites.
Too much use of pesticides is harmful.
Overcultivatinf produces poor soil structure etc
2 examples of how to encourage beneficial organisms.
Encourage frogs and toads to eat slugs by placing a pond.
Log piles and bug hotels will encourage beneficial insects such as ladybird beetles to eat aphids.
How do garden practises disturb the natural balance?
Over clearing and overly neat Gardens leave no places for beneficial predators to shelter such as hollow stems of herbaceous perennials.
Unconsidered use of pesticides will decrease the presence of natural predators and delay their build up.
Sudden removal of particular plant such as poached eggs will reduce number if hover fly.
How do we restore and maintain natural balances to minimise the need for pesticides?
Plant the right plant in the right place Companion planting Crop rotation Swing at the right times Encourage natural predators
How does selecting plants avoid plant health problems.
Choice of a resistant cultivar such as Daucus carota ‘Flyaway’
Growing right plants for appropriate situation e.g. Nerine bowdenii on warm sunny south facing wall.
Right plants for soil type - carrots sandy soil.
What is the name for perfect amount of water. I.e. Water that remains in the soil after gravitational pull has worn off
Field capacity
Describe TWO examples to show how garden practices can disturb the natural balances of plant protection.
excessive use of inorganic pesticides, particularly during the middle of the day when the most beneficial creatures are active,
cutting hedges and other nesting sites for birds during the nesting season,
composting infected or diseased plant waste in the garden.
