Guidelines for handling living biostimulant products for seed treatment

Abstract

Commercial biostimulant products are gaining momentum among growers as a novel way to promote crop health and yield while reducing pesticide and chemical fertilizer application. Although preparation instructions vary across manufacturers and products, most biostimulant products that contain living organisms lack detailed handling guidelines to maintain their stability prior to application. Any accidental contamination during product preparation could therefore lead to decreased product effectiveness. In this proof‐of‐principle study, we tested how this contamination affects microbial composition over time. In the short‐term, we demonstrate that products kept at room temperature are more reliable when applied within a day of preparation. While refrigerator storage provides the most product stability across years, we recommend ordering new products each year. Our findings show that storage practices directly affect living biostimulant product composition and therefore quality. These results provide growers and distributors with practical recommendations on handling biostimulant products to maximize their effectiveness.