Black Point
Alternaria spp
Pathogen
Fungus
Hosts
Wheat
Symptoms
Very similar to black mould with superficial mould developing on the ear. With Alternaria spp this may lead to a black stain on the grain, a symptom called blackpoint.
Development
Airborne spores from dead or decaying material. Infection usually associated with previous crop stress or damage.
Favourable factors
Cool, wet and humid conditions.
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
Fungicides can offer some degree of reduction or control
Alternaria on wheat seed
