Herbicides with SX factor Rewrites Washout Rules


By Mike Abram

 SULFONYLUREA TANK washing procedures will be much faster and simpler for growers using DuPont”s new SX formulations, which will replace the old DF formulations of most of the firm”s existing broad-leaved sulfonylurea herbicides this season. But DuPont is still stressing the need for maintaining good sprayer hygiene.

“Washout procedures for current sulfonylureas are very time consuming,” admits DuPont”s technical manager Steve Cranwell. “And research suggests some growers do not follow it fully, compromising safety.”

Using SX formulations will take out a major step in the procedure – namely that of completely filling the tank, adding All Clear Extra, and leaving to stand for 15 minutes – saving considerable time and water. “For a 3000-litre sprayer, it could reduce washings by 80%, and save 90 minutes in cleaning time, allowing another 10ha to be sprayed.”

The less stringent washing procedure works because of the change in formulation. Previous DF formulations formed a suspension containing undissolved particles, says Mr Cranwell. “Those particles, if the tank isn’t cleaned properly, can be released, potentially to cause crop damage. But SX dissolves completely in water [so there aren’t any particles].”

 The new two-stage rinsing process also doesn’t require the use of All Clear Extra, as previously. “But we are continuing to advocate its use because it is an effective tank cleaner for all products not just sulfonylureas.”

But don’t be tempted to use the quicker washout procedure with other sulfonylureas. “It is only for SX formulations,” he says.

For the coming spring, many of DuPont”s cereal broad-leaved sulfonylurea herbicides will be in SX formulations, replacing the DF formulation, which will not be available. “Ally, Harmony M, Quantum and Calibre will all be SX, the latter three all having new rates, as well as some other products that are sold by selected distributors,” says DuPont”s herbicide product manager Neil Morey.

But Ally Express and Harmony Express will not be this season, nor will grassweed sulfonylureas based on Lexus, or sugar beet herbicide Debut, he adds. Price for the new range has yet to be determined. “Any premium, if there is one, will be modest,” says Mr Morey. mike.abram@rbi.co.uk