Chrysanthemums in Aberdeen
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UK Directory of
Common
 Chrysanthemum
Ailments

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Common Pests:
-
Aphids
- Thrips
- Leafminer
- Earwigs
- Slugs 
- Whitefly
- Capsid Bug
- Caterpillars
- Red Spider Mite
- Vine Weevil
- Sciarid Fly
- Stool Miner

Common diseases: 
- White Rust
- Verticillium Wilt
- Powdery Mildew
- Crown Gall
- Chrysanthemum Rust
- Botrytis

Common disorders:
- Nitrogen 
- Phosporus
- Potassium 
- Magnesium
- Manganese
Boron
- Copper
- Iron
- High Salt levels

Suggested settings:
- Monitor
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Printer

Webmaster:
- contact me

Date last updated: 
19 October 2008

 

Botrytis/Grey mould (last updated 19 October 2008 )

Grey Mould (Botrytis cinerea) is probably the most common disease of vegetables, ornamentals, tubers, corms, bulbs, fruit, as well as many arable crops, and is almost certainly the most common disease in glasshouses. Predominantly a blossom blight and a fruit rot, it can also cause damping-off, stem canker, leaf spots and root rot. Infection often spreads to other adjacent produce after harvest. Small yellow-tan, depressed leaf spots enlarge eventually coalescing to cover the leaf, then sporulate as a light grey felt on the dying tissue. 

Plants are rarely infected directly by conidia, but indirectly though decaying petals or leaves that stick to healthy leaves. After diseased fruit or fleshy stems develop soft and watery pale brown rots, grey mould sporulates profusely on them as they split open. Squat black sclerotia may form, submerged within the tissue as it eventually wrinkles and dries. Seedling infection is worse in cold damp soil. Bulbs, corms and tubers are often infected while still in the ground. Lesions generally start at the crown or base. These appear soft and watery then enlarge, turn brownish spongy or corky, lose weight. Chrysanthemums develop purple spots on their leaves and mummified flower buds. Any attack is at the least disfiguring so prevention is best.

Generally, Botrytis cinerea overwinters in the soil on plant debris as mycelium. Scierotia or infected plant debris can be spread with seed. Growth and sporulation during cool damp weather favours release and germination of conidia, and establishment of infection through wounds, or via mycelium, on old flowers or dead foliage.

Some foot rots may also be caused by grey mould (Botrytis cinerea) that can grow down the plant inside or over the outside of the stems and between the leaves. On bedding plants, grey mould produces leaf spotting of various types which may later behave as a general decay organism if widespread necrosis occurs.

Impact/effects on chrysanthemums
Predominantly a blossom blight and a fruit rot, it can also cause damping-off, stem canker, leaf spots and root rot. 

Controls
Professional products: 
Iprodione - Rovral 
Carbendazim. 

For amateur gardeners:  Cheshunt Compound.


Other information 

 

Website designed and published by Paul Barlow with input from Ivor Mace
Copyright 2008 Paul Barlow.