7 March 1997

Activator gives Germans the edge

GERMAN wheat farmers are gaining a competitive advantage over their British counterparts by using a new approach to boost disease control.

"The plant activator, already marketed in Germany under the product name Bion, provides the missing link of disease control," explains Richard Leech, product manager at Novartis.

"We already have disease prevention through cultural control or use of fungicides – now we have a system which fits between the two, very similar in principle to vaccination techniques used in humans.

"The chemical triggers the plants own resistance to disease early in its life cycle. It takes about five days to become fully active and presymptomatic application can provide disease resistance for much of the plants life. Used in conjunction with conventional pesticides, disease management is easier and can mean a reduction in fungicide usage."

Currently undergoing UK pesticide registration, the activator has an anticipated commercial release date of 1999.

Meanwhile German farmers, benefiting from a less bureaucratic registration process, are already taking advantage of the chemical.

"The activator is a very safe, environmentally friendly product," explains Mr Leech. "In Germany, it falls into a category termed plant tonics. These chemicals dont have to undergo registration through conventional routes.

"In the UK, this chemical group is not recognised, and therefore the activator must follow the standard three-year registration process for pesticides."

German commercial usage of the activator showed positive yield benefits last year. "We had about 100,000ha of commercial usage across a wide range of soil and farm types throughout west and eastern Germany," explains Mr Leech.

"The conventional disease control programme used by Germans is very similar to our own. Stem base treatment at GS32 for septoria, rust and eyespot is followed late in the season with a flag leaf treatment.

"In trials the activator went on earlier than normal fungicide treatments at GS29. It was applied at a standard rate of 60g/ha using conventional machinery and often in conjunction with other early season treatments, such as growth regulators or liquid fertiliser.

"In some cases the activator was the sole form of disease control, whilst in others it complemented a chemical regime."

Susceptible varieties, such as Kanzler, already showed mildew establishment. In those cases Bion was applied in conjunction with a curative application of fenpropidin, to knock out the mildew first and then allow Bion to take full affect.

"The average yield benefit achieved from the trial was over 0.5t/ha," says Mr Leech.

"Weve typically seen 60-70% control of mildew infection when using the activator. Even in cases where there has been good inherent varietal resistance to mildew, the activator has been able to increase resistance."n

Early season sprays of plant activator or tonic awaken cereals disease defences, says Richard Leech.


PLANT ACTIVATOR


&#8226 Stimulates plants defences.

&#8226 Applied about GS29.

&#8226 Best on mildew.

&#8226 100,000ha treated in Germany.

&#8226 0.5t/ha yield benefit in trials.