R2103 1.1 – 1.3 Plant Health Maintenance COPY Flashcards
What is meant by physical control?
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:
- Can be expensive to set up in terms of obtaining equipment and keeping it maintained
- Potential safety issues relating to incorrect use of equipment, such as unsafe use of equipment due to poor training, unsafe removal of infected trees and unsafe burning of infected plant material
- Requires tools using hand methods to be kept scrupulously clean to avoid spreading pests and diseases
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 cultural control?
2 benefits 2 limitations
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:
- Fits 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
Limitations:
- Time consuming
- Not available for all pests
- Many only available for glasshouses
- Control may itself become a pest
Examples of cultural control and benefits/limitations
Benefits:
- Very simple to use, fits in with daily routines and has long-lasting effects
- Can be time consuming
- With regards to crop rotation helps maintain healthy soils in terms of structure, fertility and reduction of soil erosion
Limitations:
- Requires knowledge of the techniques and procedures for crop management
- Sole use will not suppress all pests and disease. Often required to be used in combination with other methods.
- Some diseases last longer in soil than rotation cycle
Benefits and limitations of chemical control?
Benefits:
- Rapid control
- Products are easily accessible
Limitations:
- Can be dangerous to humans, animals and plants
- Can result in pest, weed and disease resistance through overuse
How do garden practises disturb the natural balance?
- Monocultures – if a pest or disease is present then it is likely to spread more quickly.
- Disturbing the organic content of the soil by removing crops and crop residues and not adding more organic matter will cause a reduction in the soil micro-organisms and soil organisms. Some of these could be useful predators of pests.
- Over clearing and overly neat gardens leave no places for beneficial predators to shelter, such as hollow stems of herbaceous perennials.
- Pesticides will decrease the presence of natural predators and delay their build up.
- Removal of beneficial plant such as poached eggs will reduce number of hover fly.
How do we restore and maintain natural balances?
Range of habitats
- Sunny areas, to suit meadow flora and fauna
- Shaded and semi-shaded areas to mimic woodland and woodland edge or hedgerows
- Wet areas to encourage river and pond flora and fauna.
- Overgrown areas for seclusion for birds and animals and give shelter for larger animals such as hedgehogs. Vegetation including twigs and leaves should be left to decay, broken down by insects and fungi. Flowering plants should be allowed to set seed to provide food for birds (e.g. teasels for goldfinches)
- Introduction of nest boxes, hives, hedgehog boxes and log piles to provide homes for beneficial organisms
Grow a variety of suitable plants together
- Veg crops mixed with annuals to attract beneficial insects, e.g. Limnanthes douglasii for hoverfly
- Plants can be grown to attract beneficial organisms
Manage lawns
- Reduce use of herbicides and fertilizers
- Use wildflower and grass mixes
- Leave areas of uncut grass
Manage soils
- Living soil – ensuring soil organisms and micro-organisms are present and healthy in the soils
- Soil nutrition – make sure that organic content that is lost from soils is replenished. This is to ensure healthy soil organism populations.
Benefits of crop rotation?
• Soil fertility:
different plants need different nutrients, avoids depletion
• Maintains soil structure and reduces erosion:
dense planting keeps soil in place
• Weed control:
large leaves suppress weeds and their ability to re-seed
• Pest and disease control:
during periods when host plant absent this reduce build-up of spores, eggs and pests
Risks to people and the environment from cultural control?
- Follow guidelines and correct procedures for the use of cultural control methods
- Plants should be inspected regularly for signs of damage or pest and disease attack. Any badly affected parts should be removed. Diseased material should be disposed of according to correct procedures.
- Follow training received in the use of work equipment
What is meant by contact/selective/systemic=translocated/herbicides?
Example of weedkiller and name of active ingredient
Where it could be used
Contact:
- Direct contact. Enters the leaf or stem and kills the the tissues of susceptible plants in the areas where they have entered. Non-selective and non-residual and work simply by scorching off weed foliage.
- Weedol Gun!; acetic acid
- Annual weeds and perennial weed seedlings growing in between garden plants
Selective:
- Will cause death to only a restricted number of plant species. Systemic. Foliar, translocated, slightly residual
- Roundup for Lawns Weedkiller (No Glyphosate), 2,4-D
- Active ingredient: fluroxpyr
- Broad-leaved weeds in lawns
Translocated (systemic):
- When applied to the foliage the herbicide moves down via the vascular system into the root system of the weed.
- e.g. glyphosate is a total translocated weedkiller; along with 2,4-D and dicamba it is a foliar-applied herbicide
- Glyphosate Weedkiller, glyphosate
- Useful in control of deep-rooted perennial weeds
Total:
- Causes death of green tissues/roots of all herbaceous plant species
- Fast Action Roundup, glyphosate
- Clearing weeds on waste ground and parking areas
