Diseasea Flashcards
Rose blackspot
Fungus
Likes warm, moist, damp air caused by a lack of airflow.
PHYSICAL CONTROL Open up crown, remove congestion and dry out canopy.
Remove diseased leaves and stems and leaf litter and burn it.
Can pass from plant to plant due to overcrowding.
Ash mould (a type of Botrytis)
Billows plumes of spores so as you cut it off, bag it, so the spores don’t spread around. They spread on high sugar, soft tissue cells so often on fruits.
Box blight
Fungal infection caused by damp and congestion.
Starts as brown tip on leaf and slowly spreads though plants.
CULTURAL CONTROL Give it more space by planning for ideal spacing and monitoring frequently.
Reduce stagnated air pockets and avoid cutting in wet conditions.
Burn all cuttings
Bacterial canker
Found on prunus species.
Cherry plum apricot
Bacteria backtracks into stem tissue and it acts like an
Open wound seeping sap.
PHYSICAL CONTROL Cut it out or compartmentalise infection and improve abiotic factors.
(Fungal canker is dry and peeled bark and you can cut back to healthy tissue)
Damping off
Fungal infection
Cell collapse that spreads from radicle and no recovery from it.
can be caused by botrytis when it’s humid, damp and warm.
CULTURAL CONTROL this is a HYGEINE problem. Clean water, watering cans, trays and pots. (use bleach/ alcohol or fairy liquid in small amounts)
Don’t oversaturate your seedlings, ensure drainage is good,
Black bean aphid
PHYSICAL CONTROL Often found on broad beans at the top of the plant under leaf so taking out the apex of plant removes their habitat and helps plant bush out.
CULTURAL CONTROL Sowing too early gives these pests more opportunity to thrive.
cabbage white butterly/ caterpillar
decimate cabbages
PHYSICAL CONTROL- Net cabbages with a very fine gauze, raise the net as plant grows so that the foilage doesn’t touch net, pick caterpillars off or blast with hose, encourage blue tits and birds
BIOLOGICAL CONTROL a bacterium spray that kills caterpillar only
Capsid bug
approx 4mm, 28 species
Nocturnal
Live in the leaf litter and old shrubs
They blind shrubs by damaging the foliage at juvenile growth, creating a weak/ lacy leaf. Can affect all plants.
PHYSICAL CONTROL Clean up leaf litter and rotting materials and burn
Chafer bugs (Cockchafer beetle larvae)
Bugs have brush like antennae
Acorn size bug, they just fly mate and die but their large (50p size) grubs are bothersome in lawns, feeding on grass roots, killing grass and then being dug up by wildlife. Large white grubs with brown heads and LEGS.
PHYSICAL CONTROL Aerate, scarfiy and feed lawn, avoid waterlogging.
BIOLOGICAL CONTROL Use pheromone flying insect trap in APril/ May to trap the female and stop breeding cycle.
Flea beetle
eats spinach, lettuce, brassicas and other leafy greens
Tiny round black bugs with oily type shine
CULTURAL CONTROL Sow thin and thin out crop so that you dont have a dark dense canopy.
These perpetuate in soil or can come in on the wind, so crop rotation and growing late or early can help
Froghopper in cuckoo spit- looks unsightly
Adults suck sap from plants and so can allow eg fungus into rhodedendron bud blast
PHYSICAL CONTROL knock them off or hose them
Glass house red spider mite
Arachnoid family
Feeds thru probiscus on plant sap and protects itself ina web.
CULTURAL CONTROL These like hot dry conditions so temperature control can help. Regulate temperature and ventilate and introduce moisture.
BIOLOGICAL CONTROL Introduce a predatory spider mite that will eat them all and then die off itself.
Horse chestnut leaf miner moth larvae
The egg is laid in leaf anf then larvae eats its way thru palisade mesophyll layer adn drops in the leaf litter below.
CULTURAL CONTROL Remove and burn leaf litter each year to impact on breeding population.
PHYSICAL CONTROL Use a pheromone trap for the males.
Lily beetle
red beetle on lillies, fritillaries
breed prolifically
Grub covers itself in its own faeces so unattractive to predators.
They make holes in the leaves of plants
Defense mechanisms- the bugs drop to the ground and lie on back
PHYSICAL CONTROL Burn leaf litter
Mealy bug
A sap sucker that draws out sugar from leaves, It excretes a waxy honeydews which keeps predators away
especially found on Clivia and cacti, mainly indoor and in warm weather
PHYSICAL CONTROL knock them off wiht paint brushes and squash them, they can survive and walk to new plant so kill
Scale insect
Puts proboscis into plant and then forms a scaly cover and stays there for remainder of lifecycle
Adult scales and egg masses can be removed when seen but this may not reduce large populations
CULTURAL Encourage predators in the garden, some ladybirds, parasitoid wasps and some birds will eat scale insects
BIOLOGICAL The nematode Steinernema feltiae
sciarid fly
Larvae causes damage and they thrive in damp. anaerobic conditions.
they cause damage to roots during germination
CULTURAL freeze compost before you re pot to ensure it is sterile, and drop organic content from compost
Slugs
Like moisture rich soil and shade, love Hostas
PHYSICAL CONTROL Surround susceptible plants with gravel or mulch with wool pellets as slugs don’t like the texture.
Keep plants away from walls as slugs can climb and drop onto them, overcoming barriers.
BIOLOGICAL CONTROL USe nematodes above 12 degrees in wet conditions
Copper tape oxidises too quickly
Egg shells/ coffee grinds change the pH of soil
Vine weevils
Create notches in the edges of leaves
Found in pot plants, hostas, heucheras, bay, eunonymus
Adult weevil is nocturnal and can live in the stem tissue of plants and come out at night to eat leaves
The grub is large, c shaped and has NO LEGS
Remove and destroy or use a BIOLOGICAL nematode that eats grubs
Whitefly
2mm, problem in glass houses
small see thru fly that can be found on the back of the leaf like clouds of white dust
larvae are sap suckers
they like spells of hot dry weather
BIOLOGICAL Incarsium formosa is a parasitic wasp that lays eggs in their grubs and kills them
Downey mildew
Caused by overhead watering, water logging and excessive wetness.
Yellow splotches, inconsistent colouring
An oomycyte.
CULTURAL CONTROL Affects similar crops so crop rotation and plant spacing can solve it
Honey fungus
Visible dark honey coloured carpet of mushrooms are the fruiting body of the organism underneath which is black shoelace type rhizomorph strands which affect and kill the bark and eventually the whole plant.
Doesn’t usually affect herbaceous plants.
Sometimes there is a bulge on root flare of tree as the plant is trying to respond to the infection.
PHYSICAL CONTROL Scrape back bark, there will be a strong odour of mushroom soup. Cut it all out and burn it, you cannot replant on the same soil.
NO CHEMICAL CONTROL for this.
Pear rust
A fungus that takes the vigour out of plants, affects leaves and photosynthesis.
Looks like a brown wart with white spore pods hanging off it. It overwinters on junipers (does no harm) then returns to Pear
PHYSICAL CONTROL Cut out tissues affected and burn
CULTURAL CONTROL Choose rust resistant specimens
Powdery mildew
Appears when conditions are dry as a white talc like powder across leaves (cucumber, flox, aster etc)
Irrigate well in dry conditions, take away leaves , mulch plants and improve abiotic factors.
Fasciation
A genetic disorder where cells mutate and do something unusual, these don’t always perpetuate in the plants seeds and can be pruned out.
