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Botrytis



P_rosebotysis

Botrytis

Usually appear in

All year


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Caused By:-     The Fungus Botritis cineria

Description

Botrytis cinerea(Botryotinia fuckeliana) has a very wide host range and produces white to gray to brown fungal growth on infected areas. The affected area eventually turns black and can resemble blackspot on roses.
It is usually always present in the wind, but there a number of closely related species which are much more specific, including those infecting snowdrop (B. galanthina), peony (B. peoniae) and broad bean (B. fabae).
Botrytis cinerea is a saprophyte (a micro-organism living on dead organic material, where it forms black, seed-like resting structures (sclerotia)) on dead plant material, but it can also infect living plants under damp humid conditions.
It normally needs a wound or other stress for the infection to get a hold and can lay dormant in fruits until they ripen probably because it needs the sugars generated by a ripening fruit.
On soft fruit, particularly gooseberries, Botrytis may cause die-back of branches with or without the grey mould being present. On strawberries, grapes and other fruits, Botrytis infection leads to brown rot of the fruit, often as the fruit is ripening.
Picture by Petr Kapitola, State Phytosanitary Administration, Bugwood.org.
See these other Grey Moulds and Botrytis fungi Bean Chocolate Spot, Grey Mould, Lettuce Grey Mould, Lily Disease, Onion Neck Rot, Peony Wilt, Rose Grey Mould, Snowdrop Grey Mould, Strawberry Grey Mould.


Control

Controlling this fungus is often difficult as it is so widespread so prevention is better than a cure.
Affected areas of the plants should be cut out and disposed of or burnt. Spraying with a fungicide is often not successful, but I have found that Scotts Rose Clear gives some control. Several sprayings over a long period may be necessary. Systemic fungicide is often necessary as the fungus can live in the tissue of the plant and can cause branch die back.
Good hygiene and anything done to improve air flow will to helps prevent an attack.
Soil sterilants like Armillatox or Jayes fluid can be used on soil in winter.



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