New formulations using nanotechnology could help either boost
activity or reduce doses of agrochemicals, a researcher in the
field has claimed.
Many organic pesticides had a low solubility in water making
them difficult to apply in water, Steve Rannard of
IOTA NanoSolutions explained
at the British Crop Production
Council congress.
That was overcome by a number of different methods in existing
formulations, such as dissolving the active ingredient in a solvent
or emulsion or grinding it into such small particles it formed a
suspension or dispersion, he said.
But both methods have drawbacks, particularly in the use of
solvents, which is under increasing regulatory pressure, while
grinding only works on active substances that have high melting
points.
"We've been working on a
technology
that allows a particulate dispersion without grinding," he
said.
By using a neat procedure, that involves dissolving the active
in oil, mixing the oil with water containing a water-soluble
material, freeze drying, and then removing both the ice and oil,
tiny nanocrystals of the active ingredient are formed mixed with
the powder form of the water-soluble material.
That dissolves when put into a spray solution dispersing the
nanoparticles into the solution. "They won't dissolve but form
dispersions that behave almost like solutions."
Nano-dispersed formulations have a number of advantages, his
colleague David Duncalf explained, including improving performance,
and reducing packaging waste and shipping costs, as well as not
containing any solvents.
In trials with a "world-leading" fungicide, which the firm
wouldn't name at the conference, its new nano-dispersal formulation
had shown far superior fungicidal activity than the commercially
available formulation, he said.
"On fungus-inoculated agar plates the commercial formulation
starts to lose control at 0.1% and gives no control at 0.01% dose.
The plates are still fungus-free at 100 times dilution with the
nano-solution," he claimed.
In greenhouse tests a quarter dose of the new formulation gave
the same level of performance as full rate of the commercial
product, Prof Rannard said. "It gives the chance of enhanced
efficacy with the same dose, or equal efficacy with a lower
dose."
The new formulations could be on the market in a couple of
years, he hoped. "We have ongoing relationships with some big
companies. We're not trying to develop our own products but rather
partner with experts."