Pest & Diseases

Question 1

Name 5 diseases

Answer 1

Bacterial canker
Coral spot
Honey fungus
Botrytis (grey mould)
Rose blackspot

Question 2

Name 5 pests

Answer 2

Vine weevil
Stem and bulb eel worm 
Slugs & Snails
Squirrels
Aphids

Question 3

Coral spot - how it looks & how to treat

Answer 3

Coral pink raised spots on woody stems.
Cut out diseased branches/stems and destroy.
Affects woody plants, Acer, Lime, Horse chesnut.

Question 4

Bacterial canker - how it looks & how to treat

Answer 4

Sunken patches on the stem/trunk. Die back. Brown leaves.
Cut out diseased branches or stems back to healthy growth and destroy.
Affects fruit trees such as apple, and prunus and plum trees.

Question 5

Powdery mildew - how it looks & how to treat

Answer 5

Powdery white residue on leaves. Plants will lose vigour as unable to photosynthesise.
Caused by humid top, dry roots.
Irrigate at roots. Mulch to retain moisture. Remove damaged leaves/stems and destroy.
Courgette, sweet pea, roses, honeysuckle.

Question 6

Honey fungus - how it looks & how to treat

Answer 6

Dieback. In spring branches are bare. Decreased vigour. Toadstools at the base of the tree.
No cure!
Excavate and destroy.

Question 7

Rose black spot -how it looks & how to treat

Answer 7

Black spots which appear on leaves and may merge.  Leaves will then turn yellow and die. Decreased vigour.
Remove fallen leaves and destroy.
Prune in February.
Promote good air flow.
Tebuconazole.

Question 8

Stem & Bulb eelworm - how it looks and how to treat

Answer 8

Twisted contorted foliage. 
If cut bulb in half brown rings.
Loss vigour
Yellow leaves
No flowers just leaves
Remove infected plants and leave ground fallow for 3 years
Buy certified stock (onions, garlic)
Hot water treatment –
commercial 44.5 °C for 3 hours kills nematode

Question 9

Grey mould (Botrytis) - how it looks and how to treat

Answer 9

Affects any plant. Remember strawberries!
Grey powdery coating covers flowers/leaves.
Flowers & buds shrivel and die. Grey fuzzy mould.
Remove infected foliage. Reduce humidity. Prune or space plants to allow air flow. Do not overwater.

Question 10

Vine weevil - how it looks and how to treat

Answer 10

Affects many plants particularly in containers.
In autumn through to winter the larvae eat the roots.
Adults eat notches in leaves, which doesn’t kill the plant but is a visible sign. Discolouration of foliage.
Treat with a nematoid which is watered in. Pick off adults at night. Copper tape. Or water in a chemical on ornamental plants only.

Question 11

Aphid - how it looks and how to treat

Answer 11

Lots of different types.
Shiny coating on leaves due to honeydew excretion. Distorted foliage. Treat with soapy water spray and wash off with fingers. Or spray off with powerful jets of water. Or use a chemical spray. Or encourage biodiversity - ladybirds.