24 July 1998

Fusarium record

THE highest ever levels of fusarium ear blight in wheat has been recorded in all regions of England and Wales, according to a Central Science Laboratory and ADAS survey.

Wet weather is being blamed for the epidemic. Not only does the disease cause poor grain fill, but it can also lead to mycotoxin development in affected crops.

Mycotoxins, whose development is favoured by cool temperatures and high humidity, can be harmful to humans and livestock if consumed in significant quantities.

"At this stage we do not know which species of Fusarium is involved in the epidemic," said Judith Turner, senior plant pathologist at CSL, York. "But if it is F culmorum then the threat of mycotoxin contamination will be greater," she added.

Predicting the magnitude of the threat to yield and quality and mycotoxin content is impossible, but survey data indicated that the disease was currently affecting 1% of the total ear area. Field trials carried out at CSL over the past three years have indicated that, under favourable conditions, disease severity could increase at least 10 fold between now and harvest.

Ms Turner added that there were also potential risks to next years crops from high levels of infected seed, and increased inoculum in the soil. "Farmers using their own seed should get it tested," she advised.