Enhancing agrichemical delivery and seedling development with biodegradable, tunable, biopolymer-based nanofiber seed coatings

T. Xu, C. Ma, Z. Aytac, X. Hu, K.W. Ng, J.C. White, P. Demokritou
The Connecticut Agricultural Experiment Station,
United States

Keywords: nanofiber seed coatings, agrichemical delivery, seedling development

Summary:

One of the challenges in agriculture is the inefficiencies in agrichemical delivery and utilization. Herein, a biodegradable, tunable, biopolymer-based nanoplatform was developed as seed coating to enhance agrichemical delivery and seedling development. The nanofibers are synthesized using electrospinning of biopolymer blends without using any toxic chemicals or post-treatment and enable tunable agrichemical release by modulating the polymer composition and hydrophilicity of nanofibers. The germination and subsequent growth of different nanofiber-coated seeds (tomato and lettuce) as a function of agrichemical release kinetics were investigated in greenhouse studies, in the presence or absence of a fungal pathogen (Fusarium species). Results from the greenhouse studies indicate the efficacy of such nano-enabled seed coating approach to significantly improve the germination and plant growth in both “healthy” and “diseased” media conditions, due to the precise delivery of agrichemical at the right place (around the seed) while utilizing a miniscule amount of agrichemical. Specifically, the various nanofiber coatings synthesized and assessed in “healthy” media conditions significantly decreased the time to seed germination by 22% and increased total plant mass by 12-29 % compared to untreated seeds. For pathogen-infested media conditions, nanofiber coatings significantly reduced time to germination (by 30-51%) and increased germination rate, indicating that this seed nano-coating approach might be used in pathogen infested soil conditions to increase production yields. In toto, the developed nanofiber seed coating approach brings precision to agrichemical delivery and significantly improved germination and seedling biomass for the model seeds used in the study compared to conventional film coating approaches utilized by the industry, owing to its unique porous and nanofibrous structure and controlled release kinetics.