Trial product boost for broad-spectrum herbicide activity

27 August 1999




Trial product boost for broad-spectrum herbicide activity

POORER than expected results from glyphosate can often be traced back to water supplies that are too alkaline, says distributor Profarma

"If you are in a hard-water area, such as the limestone regions, increasing the dose of glyphosate may not get over the problem," says technical manager, Mark Palmer.

Now the value of using a novel water conditioner to maximise weed kill has been highlighted in company trials.

"Its main function is to adjust water pH and improve spray efficiency. It works by binding with magnesium and calcium salts in the water, and it buffers the pH to the optimum of 4.5-5. It also eases tank-mixing by making spray products more compatible and enhances wetting and spreading," says Dr Palmer.

Simple acidifiers based on acetic, hydrochloric or sulphuric acid have been less effective in Profarma trials, he says. "Another problem is that when we use them with growth regulators they become concentrated on the crop leaves by evaporation and can cause a phytotoxic reaction.

"We have had this new product in replicated cereals trials for three years and find it gives very consistent results with growth regulators Moddus and chlormequat.

"It also works well with Dursban, dimethoate and the blight spray Curzate. They are all chemicals, which tend to break down quite quickly at high PHS. A January wheat bulb fly spray of Dursban left unapplied because of catchy weather could, depending on the pH, lose 10-15% of its activity in a matter of hours," he says.

"With glyphosate in hard water conditions it can be better than adding an extra litre/ha of the herbicide. And at about £1.80/ha it is also cheaper." The tallow amine, Ethokem, often used as a glyphosate enhancer costs about twice as much, he notes.

Application rate is determined using a simple water testing kit.

Although already used by the firms customers, the products identity is subject to a secrecy agreement.n

GLYPHOSATE ENHANCER

&#8226 Water conditioner.

&#8226 Overcomes hard water.

&#8226 Dose guide kit.

&#8226 More consistent results.


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