Nanoparticle pesticide carriers for soybeans
In June 2021, an article titled “Nanoparticle-Based Pesticide Formulations” was posted on this website. The subject matter of the article dealt with a potential technology that involves using biodegradable nanoparticles derived from cellulosic waste as an adjuvant that can be added to herbicide spray mixtures to reduce drift. The definition of a nanoparticle from that article is repeated here.
“A nanoparticle or ultrafine particle is defined as a particle that is between 1 and 100 nanometers (nm = 1 billionth of a meter) in diameter, or at least one dimension is less than 100 nm. Particles of this size cannot be seen with ordinary optical microscopes. Thus, their detection requires the use of an electron microscope. They usually do not sediment or ‘settle out’ like colloidal particles, and easily pass through common filters. They have a very high surface area to volume ratio, which makes them valuable for mixing with pesticides–i.e. the high surface area will hold a large amount of pesticide molecules.”
An article titled “Impact of zein and lignin-PLGA biopolymer nanoparticles used as pesticide nanocarriers on soybean growth and yield under field conditions“ by Bonser et al. [Agrosystems, Geosciences & Environment, 6, e20350, https://doi.org/10.1002/agg2.20350] evaluates using nanoparticle pesticide carriers on soybeans. Details of and results from the research follow.
• Biopolymer nanoparticles are designed to be biocompatible and biodegradable, and were developed as an alternative to metallic nanoparticles. However, they must be field-tested on a targeted crop prior to their widespread field use with pesticides.
• A series of laboratory and field experiments [conducted in Louisiana] were conducted to evaluate the impact of using biopolymer nanoparticles as carriers of pesticides on soybean seed germination, root growth, plant growth and development, and insect feeding on treated soybean plants.
• Two biodegradable biopolymer nanoparticles were used–zein [made from corn protein] and lignin [abundant plant material that forms key structural materials in support tissues of most plants].
• Both zein and lignin nanoparticles were applied as seed treatments to soybean, whereas nanoparticles derived from zein were applied as a foliar spray to soybean plants at stage R2.
• Feeding by soybean looper insects was used to determine the effect of the nanoparticles on the soybean plant’s susceptibility to foliar-feeding by insects.
• Growth rate, percent seed germination, and root length were not affected by seed treatment nanoparticles.
• The plant’s susceptibility to looper feeding was not affected by their application as a seed treatment or as a foliar spray at R2.
• Foliar application of the zein nanoparticles to soybean plants did not affect flower abortion or pod set.
• The results from this research indicate that biopolymer nanoparticles derived from zein and lignin can be used with seed treatments and foliar sprays applied to soybeans with no subsequent negative effects to the soybean plant or its susceptibility to insect feeding. These results thus support the use of nano-enabled pesticide delivery as a useful tool for the application of soybean pesticides.
As mentioned in the above-linked June 2021 article, any new technology that has the potential to reduce the off-target deposition of pesticides that are applied to soybeans is worthy of attention. The results from the research described in the above-linked journal article support the use of zein and lignin nanoparticles as adjuvants when applying pesticides to soybeans.
Composed by Larry G. Heatherly, July 2023, larryh91746@gmail.com