A Seed Coating Delivery System for Bio-Based Biostimulants to Enhance Plant Growth

Abstract

A novel delivery method for the application of bio-based biostimulants as seed coatings was developed using different sources of liquid and powder forms of vermicompost and soy flour. Micronized vermicompost (MVC) and soy flour (SF) were mixed in different combinations as dry seed coating blends and applied using rotary pan seed coating equipment. The physical properties of coated seeds were measured, and as binder concentration increased, coating strength increased. The rates and percentages of germination of the newly developed coating formulations of SF+MVC did not decrease the germination parameters and were not significantly different than the control. However, the SF, SF with concentrated vermicompost extract, and SF + MVC from dairy manure increased the seedling vigor index by 24, 30, and 39 percent, respectively, compared to the control. Plant biometric parameters and nitrogen uptake per plant were also significantly higher for SF and SF+MVC coated seeds than the control, in a greenhouse environment. This is the first seed coating study to show an enhancement of plant growth with vermicompost, and vermicompost in combination with a plant-based protein that serves as a dry seed coating binder and biostimulant, respectively. Seed coatings developed in this study can serve as a model for development of the delivery systems of seeds for the application of bio-based biostimulants to enhance early plant growth.