Advances in Formulation Technologies for Microbial Biocontrol Agents: Carrier Systems, Encapsulation Strategies, Commercialisation Challenges and Future Prospects

Abstract

Aims: This review examines recent developments in the formulation of microbial biocontrol agents (MBCAs) for the sustainable management of plant diseases and insect pests. Particular attention is given to formulation approaches that help maintain microbial viability, improve storage stability and enhance performance under field conditions. Methodology: Published studies on the formulation of important microbial biocontrol agents, including Trichoderma spp., Bacillus spp., Pseudomonas spp., entomopathogenic fungi and viral bioagents, were reviewed. Conventional formulations such as wettable powders, granules, liquid suspensions and oil-based products were considered alongside newer approaches, including nanoformulations, hydrogels, biofilm-based inoculants, microbial consortia and smart delivery systems. The role of different carriers, additives and encapsulation methods in protecting microorganisms and improving their release and persistence was also assessed. Key Findings: Formulation is one of the major factors determining the successful use of microbial biocontrol agents. Conventional carriers such as talc, peat and compost are widely used because they are relatively inexpensive and suitable for large-scale production. However, they may not provide sufficient protection to microorganisms when exposed to unfavourable environmental conditions. Advanced carriers, including alginate, chitosan, hydrogels and other biodegradable polymers, offer better protection and can improve controlled release and microbial persistence. Their wider application, however, is often limited by higher production costs and more complex processing requirements. Newer approaches such as nanoencapsulation and biofilm-based formulations have further improved microbial survival and storage stability. The development of climate-resilient formulations and the increasing availability of commercial microbial products in India and elsewhere show their growing potential for practical use. Nevertheless, variable field performance, limited shelf life, production costs, lack of standardisation and regulatory challenges remain important constraints to their wider adoption. Conclusion: Improved formulation technologies can make microbial biocontrol more reliable and practical for crop protection. Future research should focus on biodegradable carriers, climate-resilient and controlled-release formulations, better storage stability and precision delivery. Artificial intelligence-assisted formulation development may also help optimise microbial products and support their wider use as sustainable alternatives to synthetic pesticides.