Barclay Crop Protection

Pay close attention to you water quality

Getting the most out of glyphosate

Getting the most out of glyphosate

Weed resistance ranks as one of the most serious threats to face UK arable farmers.  In that context, squeezing the best performance out of non-selective herbicides has never been more important.

Growers are often encouraged to focus on application in order to secure the best efficacy, but there's another factor which, sadly, is rarely given the attention it deserves - water quality.

"Ignore the carrier of the chemical at your peril," says Bryan Pickles, technical sales executive at Barclay Crop Protection.  "There are three water quality variables that can 'short-circuit' the activity of many pesticides, leaving you with less-than-ideal performance and costing you money, both in wasted chemical and the longer-term aspect of poor weed control."

These variables are hard water, water pH (acidity/alkalinity) and the cleanliness of the water itself.

Why does hard water matter?

"When water is referred to as 'hard', this means that it contains more minerals than ordinary water," Bryan explains.  "Typically, these are calcium and magnesium.  Hardness of the water increases as more calcium and magnesium dissolve in it.

"Magnesium and calcium are positively charged ions.  When they're present, other positively charged substances will dissolve less easily than in water that does not contain calcium and magnesium.  Usually little regard is taken of the water that goes into every crop sprayer, but these dissolved minerals (cations) found in varying levels in all waters can have a negative effect on performance of certain pesticide groups.  

"For example, when glyphosate is added to the tank it binds with the cations in the water to form a strong complex which is not bio-available.  Only the remaining unbound glyphosate is fully available to act as a herbicide - and this is true for all glyphosate-based formulations."

How does Velox Arbiter solve the problem?

By adding Velox Arbiter to the water in the spray tank before the pesticide, it can 'bind-up' the deactivating cations.  All the glyphosate which is then added to the spray tank is unbound and fully available to work as intended.

Velox Arbiter is effective with all formulations of glyphosate and gives a significant performance enhancement.

What about alkaline hydrolysis?

Alkaline degradation of pesticides is almost always associated with hard water.  Many pesticides are less stable in alkaline solution: perhaps the best known example is phenmedipham.

Speed of hydrolysis measured by half-life (time taken for 50% of product to be hydrolysed)

Adding Velox Arbiter @0.25% spray volume to your spray will acidify your spray water to around pH 5 - minimising any pesticide losses.

What about water cleanliness?

Recent research has shown that the effectiveness of some herbicides can be reduced by the presence of suspended silt and organic matter, both of which can reduce the activity of the herbicides such as diquat and glyphosate.

"These products are very susceptible to inactivation by silt and organic matter," notes Mr Pickles, "so it is important to use only clear, clean water for mixing them.

"Remember that the same kind of inactivation can occur when these products are applied to plant surfaces that are covered with a layer of dust.  Dust kicked up during the spray operation may also result in reduced control, especially directly behind the sprayer."

Other benefits of Velox Arbiter

Velox Arbiter is formulated to provide two other benefits, humectancy and foam control.  Humectancy prevents pesticides drying out too quickly and crystallising on the leaf surface where they can't be absorbed.  Velox Arbiter forms a hydration sheath which prevents wash-off and allows maximum uptake.

Velox Arbiter also has a built-in anti-foam agent to ensure adequate foam control and to minimise time lost due to foaming during filling and mixing.