Spotlight on new barley fungicide

The 2014 cereal season looks to have good potential, but there are very likely to be extra disease pressures to cope with. That was the view of Dr Fiona Burnett, research team leader with SRUC, Scotland’s Rural College, at the launch of a new barley fungicide.

Given the importance of malting barley the event was held in the appropriate setting of the historic Glen Garioch Distillery at Old Meldrum.

“Winter barley was mostly early drilled last autumn and advanced crops mean more disease pressure.

“The autumn was warmer than usual and we have had very few days of frost so far.

“The autumn rainfall was around average, but of course January has been very wet, with around double the normal rainfall, “she said.

These factors alone are enough to put Dr Burnett and fellow agronomists on red alert, but they also have to cope with a range of varieties which tend to have only moderate to poor disease resistance especially to the Scottish scourge, rynchosporium.

There is also a fairly limited chemical armoury, with much reliance on the active ingredient prothioconazole.

As Peter Hughes of chemical manufacturer BASF pointed out, frequent use of one chemical is not sustainable – while claiming that his company’s new product Adexar offers a new alternative.

This is essentially a formulated partnership of BASF’s established SDHI wheat fungicide Xemium and epoxiconazole, which Mr Hughes said was the strongest member of the azole family of fungicides.

Adexar now has the all-important approval for use on malting barley and will be available for use this spring, but only at half full label rate.

Dr Burnett stressed it was important to stick to the recommendations. As with most chemicals, using high rates only hastened the build-up of fungicide resistance.

“This is an important stressed Dr Burnett.

In general a good fungicide programme will lead to a two-tonne per hectare response in winter barley and a 1.5 tonne per hectare response in spring barley.

In trials in 2012Adexar showed good green leaf retention. This is especially important in barley where even an extra 5% of green leaf late in the season can be significant in terms of yield.

BASF is based in Lumbergerhof, West Germany, and spends around 430m euros annually on agricultural research and development.

With a new molecule taking around 10 years to reach the stage of becoming an approved and tested active ingredient, the costs are very considerable and the

matter,” risks high – especially if it fails to meet all the regulatory requirements.

On the other hand the rewards can be high. Scottish farmers may represent a tiny proportion of the global market but they still spend around £25m on fungicides each year.

Mr Hughes said: “There is no doubt regulatory constraints are becoming more stringent almost annually, and it is slowing up our ability to release new molecules.

“The problem is that we don’t know what these constraints will be 10 years from now when an active ingredient developed in 2014 could be expected to reach the market.

“Add in increasing resistance to existing fungicides, and the impact could be far reaching.”