5 June 1998

Call for relevant trials data…

LACK of published information on how cereal varieties perform under a strobilurin fungicide regime highlights the inade-quacy of official trials, according to John Blackman of CPB Twyford.

A long-term critic of the NIAB system Mr Blackman believes the arrival of strobilurins is a significant step forward, allowing growers to maximise cereal potential. "They offer levels of disease control not seen before. We have not been able to keep wheats free of mildew before."

Strob uptake by growers has been remarkable, he says. "They are even being traded on the black market which says something. But we see no results from the official testing system."

The current system is equally inappropriate in the way it rates varieties for straw strength, he maintains. "Remember that the NIAB ratings are based on untreated trials only. We dont think that is relevant."

In normal seasons nearly all commercial crops receive at least one growth regulator. Interactions with fungicides, particularly the latest compounds, may significantly change the ratings, he claims. "Some varieties fall over even when treated. We would like to see the data published for treated trials."