Impact of zein and lignin‐PLGA biopolymer nanoparticles used as pesticide nanocarriers on soybean growth and yield under field conditions

Abstract

Abstract Nanoparticles are being utilized in agriculture as fertilizers, pesticides, and agrochemical‐carriers. Designed to be biocompatible and degradable, biopolymer nanoparticles were developed as an alternative to metallic nanoparticles, and though safe‐by‐design, polymeric nanoparticles must be field‐tested prior to largescale use. Several field studies were conducted to observe detrimental effects of biopolymer nanoparticles on plant growth and yield using soybean, Glycine max (L.) Merr., as a model system. Biopolymer nanoparticles made from lignin or zein were applied as seed treatments to soybean seeds or as foliar sprays (zein only) to soybean plants. Studies using biopolymer nanoparticle seed treatments (nano‐STs) measured the germination rates and seedling growth were evaluated in the laboratory, while stand counts, plant height, growth stage, yield, and hundred‐seed weight were measured in the field. Foliar treatments assessed nanoparticle impact on flower abortion and pod production. To ensure nano‐STs would not compromise the plant's defensive capabilities, herbivore feeding was assessed using a leaf bioassay for defoliators and a seed damage index for pod feeders. Growth rate, percent germination, or root length were not impacted by nano‐STs. In the field, nano‐STs had no impact on stand counts, heights, growth stage, yield, and hundred‐seed weights. Leaf feeding assays and damage indices indicate plant susceptibility to herbivore attack was not increased due to nano‐STs. Foliar applications of zein nanoparticles did not increase flower abortion or decrease pod set. These results indicate that biopolymer nanoparticles have no negative effects on growth, yield, and herbivore susceptibility and should be suitable for use in agriculture.