Microbial Seed Coating and Pelleting: Benefits for Field Performance

Global agriculture faces mounting pressure from climate change, stricter pesticide regulations, and the need to protect crops sustainably. This review examines microbial seed coating and pelleting as strategies for delivering beneficial microbes to suppress soil-borne pathogens and enhance crop vigor. A central challenge is maintaining microbial viability through the harsh drying, coating, and storage steps of formulation; we use this challenge as a framework for linking beneficial microbial traits with the formulation processes and materials. The value of different binder polymers, protectants, stabilizers, and inorganic fillers are discussed for improved microbial function during seed germination and early seedling growth. Preservation of microbial viability and the rapid expression of their plant promoting traits varies with microbial choice. The nonsporulating organisms, such as the effective pseudomonad biocontrol agents, require more protection in seed encapsulation than spore formers. Field studies for major global crops, soybean, maize, and tomato, with three proven biocontrol microbes, are summarized to connect microbial selection and seed coat formulation strategy with crop outcomes. We outline current regulatory and commercialization hurdles and identify research gaps toward next-generation seed encapsulation for sustainable disease management and sustained crop production.