14 July 1995

Activator to control disease

"ITS NOT the end of fungicides as we know them, but it is something very new."…"A totally new concept in plant technology."… "Quite revolutionary."

Those are some of the comments surrounding the launch of Ciba Agricultures new non-fungicide disease control agent – CGA 245704.

Promoted as a "plant activator", the active ingredient benzothiadiazole works by stimulating the plants immune response, explains Andy Leadbeater of Ciba. That triggers the plant to increase its defences as it would in response to disease attack. But the effects are "earlier and more reliable".

Although initial activity lags by 4-7 days, excluding knockdown use, subsequent activity against powdery mildew in wheat is claimed to persist "longer than current fungicide standards".

Target timing

Target timing is the T1 spray, with treatment before second node (GS32) offering up to nine weeks protection, until ear emergence.

Good systemic activity moves the material up and down the plant, and conventional spray application will be recommended. Tank mixing will be feasible, and one of the first products is expected to be a formulated mix with Cibas eyespot fungicide A8779A.

Some suppression of rusts (30-40%) and septoria has been noted, and could allow adjustments to spray programmes, suggests Mr Leadbeater.

If mildew pressure remains intense, a conventional mildewicide would then be used at the flag leaf timing, comments Cibas product manager, Richard Leech.

Efficacy is good on all varieties, and the technology is being developed for other crops and diseases.

A very low active ingredient rate (30g/ha), low mammalian toxicity, 1 hour degradation in soil and no leaching make for a good environmental profile.

&#8226 CGA 245704 was launched to scientists last week in the Hague. Approval is expected in Germany and Switzerland in 1997, and the UK a year later.

Although other manufacturers are working on some similar technology, Ciba reckons it is "well ahead of the game with a commercial product".