A new oil dispersion formulation of boscalid will offer enhanced uptake and activity over existing formulations, according to manufacturer BASF.

In new ODs, being developed as co-formulations with epoxiconazole and pyraclostrobin, the epoxiconazole component is dissolved in an oil mixture, while boscalid is dispersed within the mixture, giving improved performance in terms of uptake, spreading, rainfastness and curativity.

According to BASF European cereal fungicide technical manager Martin Semar, the OD formulation - as opposed to the current suspension concentrate (SC) formulations used for Tracker (boscalid+epoxioconazole) and Opus (epoxiconazole) - also provide improved adhesion to leaf surfaces, particularly as the spray droplet hits the leaf for the first time. Older SC and EC formulations tend to ‘bounce’ when they strike the leaf, says Dr Semar.

The OD formulations follow last season’s launch by BASF of epoxiconazole co-formulations Brutus (epoxiconazole+metconazole) and Ennobe (epoxiconazole+prochloraz), in which epoxiconazole was completely molecularly dissolved for the first time to give the highest-ever bioavailability.

According to BASF both Brutus and Ennobe have more advanced solvent and wetting systems, leading ultimately to 30-40 per cent more active ingredient being taken into the leaf, compared with Opus SC.

“An Opus droplet needs 16 minutes before it is dry on the [leaf] surface, a Brutus droplet needs two minutes,” says Dr Semar.

BASF is developing two new boscalid-based OD co-formulations for the UK market, one in mix with epoxiconazole and one in mix with epoxiconazole and pyraclostrobin. First sales are planned for spring 2011, subject to successful registration of the products for use in the UK.

According to BASF UK fungicide manager Peter Hughes, Tracker will continue, in the short term at least, to be available as an SC formulation.