Scientific Understanding of Nano-Pesticides

The emergence of any new innovation is invariably accompanied by numerous doubts and misunderstandings, and nano‑pesticides have been no exception. This concept, introduced this century alongside the application of nanomaterials and nanomedicines, remains far from fully understood. Recently, a reporter interviewed Huang Qiliang, a researcher at the Institute of Plant Protection of the Chinese Academy of Agricultural Sciences, in an effort to demystify nano‑pesticides.

Researcher Huang Qiliang, Institute of Plant Protection, Chinese Academy of Agricultural Sciences

The Past and Present of Nano‑Pesticides

In recent years, discussions on nano‑pesticides have gained considerable momentum. Surprisingly, the industry still lacks an authoritative definition, which is why no true nano‑pesticide has yet been registered. After reviewing numerous authoritative sources, Huang Qiliang defines nano‑pesticides as formulations in which, within a specific pest‑control context, the active ingredients of the pesticide are stably dispersed at the nanoscale—either in the formulation itself or in the application‑ready dispersion system—through the use of functional materials and nanotechnology. Such formulations exhibit performance characteristics that differ from those of the original formulation when applied.

Huang Qiliang further elaborated on four key elements: “control‑and‑prevention scenarios” refer to purposeful, targeted design; “functional materials and nanotechnology” denote well‑defined scientific principles and technological approaches; “nanoscale dispersion” signifies dispersion characteristics that distinguish it from conventional formulations; and “application performance distinct from the original formulation” underscores its potential to drive upgrades in pesticide products and serve as an effective substitute.
Its origins can be traced back to the emergence of microemulsion‑based pesticide products in the 1990s. From a dispersion‑scale perspective, it is classified as a type of nano‑pesticide, relying primarily on the solubilizing action of surfactants to enable water‑insoluble pesticides to spontaneously form microemulsions in water. “Perhaps we can also understand its origins from an application standpoint,” says Huang Qiliang. In recent years, low‑volume spraying technologies tailored for agricultural drones have advanced rapidly. As these systems are required to control multiple target pests and diseases simultaneously, they often necessitate the concurrent mixing and application of several active ingredients. However, conventional pesticide formulations typically suffer from issues related to tank‑mix compatibility and spray‑solution stability, which has in turn spurred the research, development, and deployment of nano‑pesticides—represented by companies such as Nanjing Shansi—that are designed to meet user needs.

Nanopesticide performance

“Nano‑pesticides possess unique small‑scale effects and controlled‑release properties that traditional pesticide formulations lack, thereby enhancing efficacy and utilization rates while aligning with China’s strategic goals of reducing pesticide use, improving efficiency, and achieving zero growth in pesticide application. Huang Qiliang is highly optimistic about their development prospects. Moreover, in terms of application technology, nano‑pesticides offer streamlined, high‑efficiency performance that conventional formulations cannot match, meeting the specific requirements of low‑volume spraying—such as that employed by unmanned aerial vehicles—for pesticide formulations. This helps reduce the physical demands of crop protection operations and boost operational efficiency.”

Moreover, it boasts broad applicability. “Nanoemulsions, nanosuspensions, and nano‑dispersions are all suitable for low‑volume spraying using agricultural drones,” Huang Qiliang added. Furthermore, slow‑release granules formulated with nanotechnology and controlled‑release systems can be integrated with agronomic practices to enable seed‑treatment applications, simultaneous application of pesticides and fertilizers, and precision spot‑application—delivering active ingredients via root‑zone, concealed release. During the growing season, these formulations can also be precisely applied at targeted locations as needed for disease and pest management, thereby helping to build crop‑health‑centric solutions or technical systems aimed at comprehensive, coordinated control of harmful organisms throughout their life cycles.

What about the cost of nanopesticides for farmers? “While their processing costs may be higher than those of conventional pesticides, they offer performance characteristics that traditional formulations lack in specialized pest management, boosting pesticide use efficiency and reducing the number of applications. From the perspective of comprehensive pest‑and‑disease control across a crop’s entire growth cycle, they ultimately save money,” Huang Qiliang told reporters. In pest and disease management, developing professional control organizations can shift from individual households relying on rudimentary, ad‑hoc measures to coordinated, large‑scale operations—akin to deploying “aircraft and artillery”—thereby effectively addressing the challenge of translating preventive and control strategies into practical field implementation. Nanopesticides’ “centralized formulation and application” represent the optimal solution for such group‑based, high‑impact operations, making them well suited for scaled‑up production. However, regulatory hurdles remain, as does the need to establish how specialized control teams can provide streamlined services—from custom formulation to on‑field “centralized formulation and application”—in response to actual production needs. Huang Qiliang further argues that it is essential to strengthen source‑level standardization and oversight of nanopesticides, rigorously manage their typical field‑use scenarios, and intensify policy guidance and support.

Research and Application of Nanopesticides

Currently, research on nano‑pesticides primarily focuses on their formation and stabilization mechanisms, their behavior during targeted delivery, and their efficacy against harmful organisms. “It is gratifying that China’s current level of research in this field is broadly comparable to that of the world’s leading countries,” said Huang Qiliang. He added that, in terms of application technologies for unmanned aerial vehicles and product performance, China’s nano‑pesticides remain at the forefront globally.

Through research, the small-scale effects of nano‑pesticides have now been largely elucidated. “However, this effect is a double-edged sword,” notes Huang Qiliang. On the one hand, it offers advantages such as enhanced stability of the spray solution; on the other hand, it may also alter the distribution patterns and dose–response relationships of the active ingredients within the target plant, potentially introducing safety risks even as it improves pesticidal efficacy. “Existing methods are no longer adequate or unable to accurately assess the safety risks of nano‑pesticides, necessitating the development of appropriate evaluation approaches and standardized protocols. This is both an urgent challenge and a major bottleneck in current nanopesticide research,” Huang Qiliang acknowledges.

“This touches on the issues of nanopesticide residues and food safety, which are of widespread public concern,” said Huang Qiliang. “We do need to accelerate the development of new methods and standards for assessing the safety risks of nanopesticides—this is a limitation inherent in the early stages of any emerging technology. However, under proper conditions of use, nanopesticides should, in theory, not give rise to novel pesticide residue or food safety concerns.”
Moreover, water-based formulations such as nanoemulsions and nanosuspensions—characterized by their nanoscale dispersion—are demonstrating superior safety and efficacy in aerial crop protection compared with conventional oil‑based or ultra‑low‑volume liquid formulations, leading users to refer to them as “nano‑pesticides specifically designed for aerial application.” “In reality,” Huang Qiliang notes, “these nano‑pesticides are not limited to aerial use; they are equally suitable for conventional‑rate spraying, with aerial application merely representing one mode of low‑volume pesticide delivery.”

Source: Farmer’s Daily, Yan Xu