21 March 1997

Ignore adjuvant advice and miss a vital trick…

MODERN spray adjuvants eliminate the "snake oil" image from which the chemical group has suffered, says a leading agronomist.

They increase pesticide reliability, offer good crop safety and are cost effective, CSC Crop Care director Keith Dawson maintains. "Farmers who ignore them are missing a trick."

Last year CSC CropCare used adjuvants Arma and Slippa on more than 16,000ha (40,000 acres) to boost sulfonylurea herbicide activity, increase uptake of late growth regulators and enhance fungicide performance.

"In our cool, wet conditions we have real concerns over uptake of trace elements and growth regulators. We have limited spray windows, and a variety of problems – broad-leaved weeds, more foliar disease and intense lodging pressure," says Dr Dawson.

Interagros managing director Mike Roche believes modern adjuvants can help offset the squeeze of falling grain prices and higher fungicide costs. By using them growers could omit a spray, cut rates or use cheaper, older triazoles.

Three years of independent work show Arma, a broad-spectrum non-ionic surfactant, boosts the efficacy of several fungicides, notably cyproconazole (eg Alto), flusilazole (eg Sanction) and flutriafol (eg Pointer), says Interagros technical director, Richard Newman.

It increases chlormequat growth regulator uptake by four times at 4C and doubles uptake at 12C, and enhances the activity of sulfonylurea herbicides which have low surfactant levels, he adds.

Slippa, an organosilicone spreader, helps fungicide penetrate between cereal leaf sheaths and stems which boosts eyespot control, says Mr Newman. It also spreads fungicides to the stem base, giving good control of diseases like mildew, he claims.n