Under the most sustained and intense blight pressure during 2007, Revus has demonstrated that it leads the field as a mid-season blight fungicide, with its combination of outstanding persistent protection and rainfastness. This has been confirmed in independent trials across the UK and Ireland reports Syngenta Potato Technical Manager, Jon Ogborn.
Speaking at the BPC British Potato 2007 in Harrogate this week (28-29 November 2007) he highlighted results from the renowned Agrisearch trials site in Derbyshire. In the trial a Revus based programme kept out blight more effectively than all other comparative fungicides, including cyazofamid and fluopicolide+propamocarb.
"In an inoculated trial designed to create very high disease pressure, the untreated crop rocketed to very high levels of infection within a week of application of the first test treatment," said Mr Ogborn. "However, the Revus programme held infection back at a very low 10% right through to the end of the first week of August, when infection in other fungicide programmes had already reached almost 30%."
Trials by Teagasc at Oak Park in Ireland also demonstrated the strength of REVUS under very high blight pressure. REVUS applications mid-season, following two early applications of FUBOL GOLD and finished off with three applications of SHIRLAN at 0.4 l/ha, produced the best result for blight control.
Cymoxonil+mancozeb again proved a far weaker mid-season combination, with infection levels at over 25%.
An SAC trial at Auchcruive tested fungicides under very extreme conditions and with extended spray intervals - longer than would be used in commercial practice, according to Mr Ogborn. "However, the extreme blight pressure highlighted the strength of the Revus based programme, which kept out blight for longer than fluopicolide+propamocarb. The trial ably demonstrated the persistent protection between applications provided by Revus," he added.
Potato growers and agronomists can now get full details of the Revus foliar blight trials results on a dedicated web site: www.revus.co.uk
Trials in 2007 have shown that using two consecutive Revus applications during periods of intense blight pressure could enhance levels of foliar blight protection.
An independent trial by Agrisearch highlighted two Revus applications during a period of high disease pressure, in mid-July, were extremely effective in holding back foliar blight infection. This was superior to a comparative programme where Revus was alternated with another fungicide.
Syngenta Potato Technical Manager, Jon Ogborn, advises this demonstrates the cumulative benefit that a pair of Revus applications can give in protecting crops through periods of intense bight pressure.
"Under normal conditions, interspersing Revus applications with alternative blight fungicides mid-season will be a common practice for prolonged protection. However, if blight pressure turns high, the trial indicates a pair of consecutive applications may be beneficial," he added.