26 March 1999

French eyespot risk test evaluated

A FRENCH method of evaluating eyespot risk by monitoring the primary and secondary release of eyespot spores has been tested in the UK by Novartis this season.

Spore counts, obtained from a series of spore traps located in crops, are added to other information held in an eyespot development model, to help quantify the risk of infection.

Chris Rowsell of Novartis says that while the spore trapping technique worked well in the field, the actual spore counting had to be done in France. "There were some postal delays and interruptions which meant that a few of the results were invalid. It was also difficult to get the work done over the Christmas and New Year period."

Gaps in the 1998/99 spore release data mean Novartis will continue to evaluate the technique before introducing it in the UK. "It will never give the whole picture, but it adds to our knowledge." &#42