Scientists combine nanotechnology and natural products to combat agricultural pests

In search of sustainable alternatives, researchers at the Universidade Estadual Paulista (Unesp) in Sorocaba have invested in the combination of nanotechnology and natural products to protect plants. The topic was addressed by Leonardo Fraceto, coordinator of the Environmental Nanotechnology Laboratory at Unesp, in a lecture presented at FAPESP Week France.

“There is a growing demand for food around the world and nanotechnology allows us to create methodologies to increase agricultural production. I’m not referring to an increase in planted area, but rather in productive efficiency”, said Fraceto.

As the researcher explained, the group's objective is to research different systems to encapsulate pest control agents, such as synthetic agrochemicals or insecticides and repellents of botanical origin. “Another line of research proposes the use of biological agents, such as fungi and bacteria, encapsulated in microparticles,” he said.

Within the scope of a Thematic Project supported by FAPESP, the Unesp group studies the mechanisms of action and toxicity of the methodologies developed.

According to Fraceto, the use of nanoparticles makes it possible to deliver the active compound directly to the location where the pest to be combatted is, reducing the amount of pesticide applied to the crop, toxicity to the plant and, consequently, environmental contamination. “The pest, on the other hand, receives a more concentrated load of the active ingredient, which allows the number of applications to be reduced,” he said.

The group developed, for example, a system for encapsulating atrazine, one of the best-selling herbicides in Brazil and already banned in the European Union due to its high toxicity.

“In laboratory tests, the polymeric nanoparticle formulation was more efficient for pest control than the conventional one. We managed to reduce the necessary dosage from 3 kilos to 300 grams per hectare. Our next step will be to evaluate the formulation in field studies”, said the researcher.

In another work, published in the magazine Pest Management Science, scientists mixed three different botanical compounds – geraniol (found in geranium, lemon and citronella, for example), eugenol (present in clove oil) and cinnamaldehyde (from cinnamon oil) – in polymeric nanocapsules made from zein, a corn protein.

“We are a multidisciplinary team and we seek satisfactory solutions from both an ecological and economic point of view. We have listed some substances that we consider interesting for the management of pests such as caterpillars helicoverpa [soybean pest], the fall armyworm [of corn] and the two-spotted mite [which attacks fruits, grains and other crops], for example,” he said.

The FAPESP Week France symposium was held between the 21st and 27th of November, thanks to a partnership between FAPESP and the universities of Lyon and Paris, both in France.