5 June 1998

YR 6/17 present in commercial crops

YELLOW rust strain YR 6/17, only seen in trial plots last year, is now present in commercial wheat crops and is affecting varieties other than just Brigadier, warn National Institute of Agricultural Botany scientists.

"This strain is now coming in on samples of Madrigal and Equinox from Lincolnshire," says NIAB plant pathologist Phil Stigwood. Recommended list candidate Aardvark is also showing the strain in trial plots, but other candidates Claire, Malacca and Shamrock are clear so far.

The straight YR17 strain of the disease is widespread in Brigadier crops across the UK. Occasional samples of susceptible varieties Hussar, Reaper and Savannah are also being received.

Mr Stigwood urges vigilance whatever the weather. "Warm days caught a lot of people out last year – if the nights are cool and damp the disease will continue to develop rapidly if uncon-trolled."