In the first year of using the Hutton Criteria in the field, it has performed better than the Smith Period at indicating blight risk, according to James Hutton Institute researcher Siobhan Dancey.
“There is less variation for the Hutton Criteria than for the Smith Period for different climatic regions,” she said.
“Feedback from the industry is that it is good at indicating risk and triggers alerts more frequently than the Smith Period but it has been a warm and wet season so we would expect more risk periods.”
Some had queried whether the six hours of relative humidity greater than or equal to 90 per cent should be consecutive or cumulatively over a 24-hour period. “There is no significant difference,” said Dr Dancey.
Using in-field rather than BlightWatch weather data also tended to trigger Hutton Criteria alerts more frequently, said Dr Dancey.