Carbonates and bicarbonates: A sustainable approach for managing plant diseases, pests, and abiotic stresses

The growing global food demand necessitates sustainable agricultural practices that minimize environmental impact while ensuring high yields. Synthetic pesticides, while crucial for crop protection, raise concerns about environmental contamination, resistance development, and harm to non-target organisms. Carbonates and bicarbonates (e.g., NaHCO₃, KHCO₃, CaCO₃) offer a promising, Generally Recognized as Safe (GRAS) alternative for integrated pest and disease management and abiotic stress mitigation. These compounds exhibit broad-spectrum efficacy against diverse fungal, oomycete, bacterial, and insect pathogens, including the clubroot protist (Plasmodiophora brassicae). Their direct antimicrobial mechanisms involve disrupting pathogen cell membranes and walls, inducing osmotic stress, and altering pH, which leads to pathogen death. Beyond direct toxicity, carbonates and bicarbonates also elicit plant defenses, inducing systemic acquired resistance (SAR) and stimulating defense enzymes (e.g., peroxidase, polyphenol oxidase). Furthermore, they enhance soil health by raising pH, improving nutrient availability, structure, and water retention, while reducing heavy metal bioavailability. These soil improvements increase plant resilience to drought, salinity, and metal toxicity, with potential benefits also arising from improved stomatal regulation. Recent advancements have introduced carbonate nanoparticles as nano-fungicides and biostimulants, offering enhanced efficacy at lower application rates. Integrating carbonates/bicarbonates into Integrated pest management (IPM) programs, especially in combination with biocontrol agents and other beneficial salts, demonstrates synergistic effects and reduces reliance on conventional pesticides. However, further research is needed to elucidate detailed molecular mechanisms, assess long-term soil impacts, optimize application methods (e.g., foliar sprays, soil amendments, nanoformulations), and evaluate compatibility with other agrochemicals. Addressing these knowledge gaps will enable the full potential of these sustainable compounds for resilient and food-secure agriculture.