Grey Mould
Botrytis cinerea
Pathogen
Fungus
Hosts
Wheat
Symptoms
Brown speckling, sometimes quite extensive, appears on upper leaves often in the presence of shed pollen. Individual grains on the ear are also infected.
Ear infection gives rise to a straw coloured lesion on most of the glume, the developing grain is then destroyed.
Development
Airborne spores arise from dead and decaying material.
Favourable Factors
The disease is favoured by cool, wet conditions from ear emergence onwards.
Importance
The effect on yield is not dramatic but quality is substantially reduced with a shrivelled, dull and dirty sample.
Germination, importance for seed crops or brewing grains will be impaired. The thousand grain weight will be reduced indicating the amount of shrivelled grain. If the infected grain is not dried properly, hot spots can be formed in the grain stores reducing quality even further.
Generally only a problem in stored grain but the inoculum arises from grain which is infected during ear ripening.
Control
Some fungicides, offer some degree of control.
