Sustainable Use of Chlorides Against Biotic and Abiotic Stresses

Abstract

This chapter explores the multifaceted role of chloride salts in sustainable agriculture, moving beyond their traditional association with salinity stress to reveal their potential in mitigating various biotic and abiotic challenges. The review analyzes the effectiveness of diverse chloride salts, including NaCl, KCl, CaCl2, and MgCl2, demonstrating their efficacy in suppressing a broad spectrum of plant pathogens, with a primary focus on fungal diseases. Chloride salts achieve this through diverse mechanisms including cell wall reinforcement, osmotic regulation, and induced systemic resistance. For example, calcium chloride treatments have shown remarkable success in controlling postharvest diseases, in some cases reducing losses by up to 90%. Similarly, potassium chloride has demonstrated promising results in managing diseases such as take-all root rot in wheat, indirectly enhancing plant health and resilience. For bacterial diseases, chloride salts such as copper chloride offer direct antibacterial activity, while others such as calcium chloride can enhance plant defenses and reduce disease severity. Chloride-based disinfectants such as sodium hypochlorite have proven effective against various plant viruses. Beyond direct pathogen suppression, the chapter also explores the use of chloride salts for insect control, highlighting their potential against aphids, stable fly larvae, and termites by disrupting various aspects of their biology, from feeding behavior to social interactions. The review also addresses the role of chlorides in mitigating abiotic stressors such as drought and heat, notably the use of calcium chloride to alleviate heat stress through enhanced antioxidant activity and flavonoid biosynthesis. Furthermore, the potential of integrating chloride salts with other sustainable practices, such as combining them with beneficial microorganisms for enhanced disease control, is discussed. While acknowledging potential phytotoxic effects and the need for careful management of sodium chloride due to salinity risks, this review emphasizes the importance of optimized application strategies tailored to specific pathosystems and environmental conditions. This integrated approach, combined with the relative cost-effectiveness and lower environmental impact of chloride salts compared with many synthetic pesticides, offers promising avenues for developing sustainable and resilient agricultural practices. © 2025 Elsevier B.V., All rights reserved.