Past paper June 2019 Flashcards
describe how and what damage is done to plants by the peach potato aphid
it sucks sap-there will be yellow/mottling leaves
curled/distorted young growth
produces honeydew
transmits viruses
what does the peach potato aphid excrete and what does that do to a plant?
excretes honeydew onto leaves.
This leads to a secondary infection of sooty mould that blocks light from reaching leaf so it cannot photosynthesise efficiently.
how does an aphid transmit diseases from plant to plant?
transmits disease through it’s stylet whilst sucking sap
name a disease transmitted by an aphid
potato leaf roll virus
what are some beneficial organisms that can be encouraged into the garden to help control the peach potato aphid?
blue tits parasitic wasps ladybirds lacewings Rove beetles
how would you encourage blue tits and other birds into a garden?
provide food eg: bird seed and fat balls,
hedges and bird boxes for nesting
name a parasitic wasp that feeds on peach potato aphids and what should you do with them to control an infestation?
Ahidus praon.
Place on plants in the evening
How do you encourage ladybirds/lacewings into the garden?
provide overwinter shelter
name some methods of shelter for ladybirds and other insects in the garden
hollow stems
herbaceous material
crevices in walls
insect hotels
what pests cause damage by biting?
vine weevil
deer
rabbit
caterpillars
what pests cause damage by rasping?
slug
snail
what is meant by the term annual weed?
completes its life cycle in one growing season.
germinates in spring, grows, flowers, sets seed and dies in one growing season
what are annual weeds found in recently cultivated soil?
Stellaria media
Poa annua
Veronica persica
what are the characteristics of annual weeds found in recently cultivated soil?
shallow fibrous roots
their seed can overwinter in the soil and remain viable for many years
four problems caused by perennial weeds in an established lawn are:
compete for light as large rosette shaped leaves block out light required by the grasses
compete for water as large leaves and deep tap roots can absorb water more readily than grasses
harbour pests and diseases
causes an uneven playing surface for sports eg: golf
Aesthetically unattractive as the broad leaves and tall flower heads look unsightly
Describe the life cycle of the black bean aphid (research a diagram)
overwinters on host plant as small, black eggs
eggs hatch in spring/april all female and wingless
colonies develop on young leaves/shoots and females produce live young
From May- winged females are produce
Winged females migrate to beans and summer host plants
in autumn, another winged generation of male and female aphids are produced that migrate back to winter host
mating takes place and the eggs are laid in crevices on stems and around buds on the winter host
what is a winter host for eggs of the black bean aphid?
Viburnum opulus
what is a summer host plant for the black bean aphid?
nasturtium
dahlia
poppies
describe the method that the black bean aphids use to breathe
tiny openings in the body wall and use of spiracles allow them to breathe.
the blind ended air filled tubes (tracheae) also disperse oxygen around the aphids body
what are physical control methods for black bean aphids?
squashing/rubbing off between finger and thumb
removal of bean shoot tips by pinching out by hand before the aphids can colonise the plant
use a strong jet of water to wash them off the plant-without damaging the plant
what are the chemical control methods for the black bean aphids?
the use of fatty acids eg:
pyrethrin
deltamethrin
what is meant by plant disease?
an abnormal growth and/or dysfunction of a plant caused by an infectious micro-organism (pathogen),
eg: virus, bacteria, fungi
what are the damages caused by honey fungus?
crown of tree can die suddenly
leaves smaller than usual
leaves paler than average
failure to flower
large crop can be produced followed by death of tree
cracking and bleeding of bark at vase of tree
dead/decaying roots
what does honey fungus do to the crown of trees in hot weather?
it can suddenly die back during hot/dry weather indicating a failure of the root system
how is honey fungus spread?
by rhizomorphs underground
through direct contact of the roots of infected trees with unaffected trees
how far can honey fungus spreads via rhizomorphs?
30m in the top 15cm of soil
what are methods of control for honey fungus?
plant resistant species
dig out the whole tree including the stump and as much root as possible
dig a trench around the affected tree and line with a butyl rubber sheet as a barrier
what are resistant tree species of honey fungus?
Ginkgo biloba
Quercus ilex
what are susceptible tree species to honey fungus?
Fagus sylvatica
what is the name of the rubber sheeting used to prevent the spread of honey fungus rhizomorphs?
Butyl
what is the purpose of a butyl rubber sheet when protecting trees from honey fungus?
by digging a trench around affected trees, you can line it with the rubber sheeting to form a barrier to prevent the growth of rhizomorphs
name some reasons for controlling weeds
remove comp. for light, water, nutrients
makes harvesting crops easier
remove host plants for pests/disease
Avoids weeds looking unsightly
name a weed in an established shrub border
Aegopodium podagraria
what would you treat Aegopodium podagraria with?
Glyphosate
what is Glyphosate and where would you use it?
a translocated chemical for a weed in an established border
name a weed in a newly cultivated soil
Cardamine hirsuta
what would you use to control Cardamine hirsuta?
Fatty acid
Acetic acid
Diquat
Fatty acid
Acetic acid
Diquat- what are there modes of action in weed control?
contact
name a weed in an established lawn
Ranunculus repens
what would you use to treat Ranunculus repens?
2,4-D
or glyphosate in bare ground
what mode of action does 2,4-D give?
a selective herbicide
how can pesticides disturb the natural balance of plant protection in a garden situation?
beneficial insects/natural predators can be destroyed esp. in middle of day-therefore biological control won’t work
overuse can damage other plants and natural habitats where beneficial insects would overwinter-pest problem could explode if no natural predators
excessive use of certain pesticides may cause resistant strains
describe effects of fasciation on plants
distorted stem that is flattened in appearance.
flowers appear distorted with flattened flower heads from the fasciated stem
describe the effects of growing an acid-loving plant in an alkaline soil
lime-induced chlorosis as manganese and iron unavailable to plant (interveinal chlorosis)
yellowing of leaves
photosynthesis reduced as Iron needed to make chlorophyll
Hydrangea flowers change from blue in acid soils to pink in alkaline soils
what colour is a hydrangea flower in acidic soils?
blue
what colour is a hydrangea flower in alkaline soils?
pink
describe two methods of avoiding frost damage on plants
take tender plants into a greenhouse/conservatory
wrap large tender plants that cannot be re-located in fleece or cover with bracken/straw to protect their growing tips
don’t plant tender plants in frost pockets or where early morning sun can damage flowers eg Camellias
apply a 75-100mm layer of organic mulch around the base of herbaceous perennials to protect the root zone
