Published on 21/07/2022
There’s a good reason for that – they are really important physical characteristics (along with adhesion). If the herbicide doesn’t stay on the plant after application, penetrate the outer tissue, and move freely from there to the roots, all before the plant locks down its own defensive mechanism, you might as well not bother spraying in the first place.
But have you ever wondered exactly how uptake and translocation are measured? For one of New Zealand’s best-known glyphosate suppliers, the answer comes down to some very fiddly, precise chemical science.
“It’s actually quite a complex process, quantifying the speed of uptake and translocation for a herbicide like CRUCIAL,” says Nufarm technical specialist Paul Addison.
It’s also a job best left to an expert. For CRUICAL, that expert was the now-retired Dr Robin Gaskin of Plant Protection Chemistry NZ, who for many years provided highly specialised analytical studies and research to agrichemical and adjuvant manufacturers world-wide.
Robin and her team at Rotorua did the uptake and translocation work on CRUCIAL before the advanced new glyphosate formulation was launched to the NZ market, and Paul says without their expertise Nufarm would not have been able to provide the hard data it has on these key performance attributes.
The same team was behind the technical analysis of CRUCIAL’s rate of uptake with Pulse Penetrant. This gave Nufarm the data to support the benefits of their premium glyphosate formulation CRUCIAL over other commercial formulations.
So how did they do it? “It’s quite interesting. That sort of laboratory study uses glyphosate labelled with the radioactive compound carbon 14, which shows up on autoradiograph imaging equipment. The concept is similar to the use of barium in human x-rays,” Paul says.
For the Nufarm tests, tiny doses of CRUCIAL with the14C marker were applied in solution to the leaves of ryegrass plants grown specifically for this purpose.
“The researchers have to simulate a normal commercial application, so they apply very small amounts of solution using a tiny micro pipette. Then the treated plants are left for a range of different intervals, from 30 minutes to 24 hours, depending on the trial protocol.”
After the designated time period has elapsed, the tiny drop (or what’s left of it) is washed off the treated leaf, and the amount of radioactivity in the plant is measured.
The treated leaf, the leaf opposite which is untreated, and the roots of each plant are processed and measured for the amount of radioactivity present.
“And that’s how we can present data and images showing exactly where the glyphosate molecule has travelled through the plant over what period of time,” he says.
Gathering such data is neither cheap nor fast but provides confidence for both resellers and end-users.
“It’s part of our product stewardship, making sure our formulations do what we say they will do.”
Key benefits of CRUCIAL and Pulse Penetrant for arable farmers are flexibility, reliability and speed, especially in spring when the natural protective waxy cuticle on grass leaves is at its thickest, Paul says.
“Without Pulse Penetrant, glyphosate cannot effectively penetrate this thick waxy layer. Uptake is reduced which then results in poor control.”
Time is always at a premium in spring, and weather can be very changeable, making rainfastness a high priority. CRUCIAL tank mixed with Pulse Penetrant should deliver commercially acceptable weed control even if light rain occurs just 15 minutes after spraying.
“No other glyphosate can match this standard. If it fails with our commercial performance guarantee, Nufarm will replace up to 100% of your initial use rate of CRUCIAL for re-treatment.”
Paddocks sprayed with CRUCIAL can be grazed, cultivated or drilled just one day after application for annual weeds, and three days for perennial weeds. This minimises downtime between spraying and sowing, and gives growers more options if they have to change their plans without warning because of the weather.
The importance of a good pre-plant spray programme can’t be overlooked when it comes to getting the very best out of your investment in fertiliser, seed and paddock preparation ahead of spring sowing.
Grass and other poorly controlled weeds can re-establish and will quickly compete with the newly sown crop. Often these grasses or weeds can’t be controlled in the crop resulting in significant yield loss, or if they can be controlled, it is usually a lot more expensive to do so.
CRUCIAL is the only formulation in the world which combines three glyphosate salts - potassium, monomethylamine and ammonium. It has a high load of active ingredient (600 g/litre), meaning more weed killing power per litre, using less product per ha. It pours easily, won’t foam and tank mixes superbly with other products, Paul says.
It comes in a range of pack sizes, from the OHS 15 litre pack, all the way up to the larger 1000 litre pod options.
For more detail contact your rural retailer or agronomy rep.