Pests and Diseases Viewer

Grey Mould


Grey Mould

Usually appear in

All year

Back to Pests and Diseases

Caused By:-     The Fungus Botrytis cinerea(Botryotinia fuckeliana)


Grey mould(also called Botrytis) is a disease usually caused by the fungus Botrytis cinerea(Botryotinia fuckeliana). This fungus has a diverse genetic variability(polyploidy) and some strains are specific to one type of plant. It normally affects plants under stress or plants that have been damaged in some way. This is especially so if the humidity around the plant is high. It will also infect healthy plants and can be expected at any time of the year. Usually there is a dense grey fungal mass affecting any part of most plants or even fruits in storage if the conditions are right. As the infection ages black sclerotia about 2mm accross are produced. These then fall to the ground and act as the over-wintering stage that is difficult to eradicate. Knocking infected leaves, buds or fruits releases a clouds of spores into the air where air currents transport them to infect new plants. Infections may start as discrete spots, but can spread rapidly. Any attack is at the very least disfiguring so prevention is best.
See these other Grey Moulds and Botrytis fungi Bean Chocolate Spot, Botrytis, Lettuce Grey Mould, Lily Disease, Onion Neck Rot, Peony Wilt, Rose Grey Mould, Snowdrop Grey Mould.


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 to kill the sclerotia or as a greenhouse sterilant.

P_mildew1 P_mildew1

Click picture to see larger view and more information   

Back to top