Nano encapsulation
Encapsulation technique is one of the various formulation techniques, in which the active ingredient is encapsulated by a synthetic or biological polymer to allow for prolonged release of the pesticide over a period of time. Such nanomaterials can dissolve in water, be stable and have maximum effectiveness of these pesticides. This technique has gained prominence in recent years due to its long term advantages.
Pesticide formulation is an important issue in the field of agriculture. The primary aim of pesticide application for crop protection is the uniform spread of active ingredients in small amounts over a large area. To achieve this objective it is ideally desired that pesticide particles should not agglomerate over the crop. During pesticides formulations the industry is concerned about reducing higher manufacturing costs, harmful environment effects, and help deliver an active ingredient which has higher initial and residual efficacy.

Process
A wet chemistry process is used wherein nanoparticles are produced inside a charged polymer template. The charged polymers are then neutralized by precursor ions, making the polymers collapse around the core ions called "core collapse" resulting in final nanoparticles with a polymer stabilizer around it. The charged polymer surrounding the core repels other "like charged" polymers thereby preventing agglomeration and helps maintain the nano size of the particle.
Usually pesticide active ingredient formulated based on nano technology is highly effective in killing weeds, avoids the problematic chemical additives that are leading to product bans in a growing number of major markets, results in improved crop yield and reduced environmental impact. Its nanoparticles can load a variety of hydrophobic molecules including those commonly used to deliver fragrance and color, as well as many pharmaceuticals and have also shown the potential to efficiently remove hydrophobes from water.
Mechanism
These encapsulation techniques enable greater control over the circumstances in which encapsulated pesticides will be released. For example, pesticides could be released quickly or slowly depending on need and under specific conditions, such as moisture and heat levels. Pesticidal applications of nanotechnology promise to reduce pesticide use, due to their more precise and targeted nature. An example is microcapsule containing pesticides that will break open in alkaline environments, including the stomach of certain insects, they can also provide in-built pesticides for crops but also in-built switches to control the release and subsequent availability of pesticides. These nano-particle pesticide have improved capacity for absorption into plants and may not be washed off as readily, thereby increasing their effectiveness.
Risks

Risks related to nano-pesticides use are to the consumers of these products, farm workers and rural residents who are also being exposed to these nano-pesticides, in the absence of any required safety testing or regulation of nano-scale formulations of already approved chemical pesticides. The size and dissolvability of nanoparticle pesticides may also mean contamination of soils, waterways and food chains and toxins rreleased to the environments, but as such, nanotechnology is frequently portrayed as introducing environmental benefits.
In future nanotech research and development is likely to facilitate and frame the next stage of development of genetically modified crops, animal production inputs, chemical pesticides and precision farming techniques.
Leading agrochemical companies like BASF, Bayer Crop Science, Monsanto and Syngenta are engaged in nanotech research in these areas and have introduced products with emulsions that contain nanoparticles.