In the quest for sustainable agriculture, researchers are turning to unexpected allies: common food preservatives. A recent study led by Lamyaa Zelmat from the Laboratory of Phytopathology and Post-Harvest Quality at the Regional Center for Agronomic Research in Kénitra, Morocco, has uncovered the potent antifungal properties of potassium sorbate and sodium benzoate against Alternaria alternata, a widespread pathogen that plagues citrus crops. Published in *Caraka Tani: Journal of Sustainable Agriculture* (which translates to *Journal of Sustainable Agriculture*), this research could revolutionize citrus disease management, offering a low-toxicity alternative to conventional fungicides.
Alternaria alternata is a notorious fungus that causes significant losses in citrus production worldwide. Traditional fungicides, while effective, often come with environmental and health concerns. Zelmat’s study explored the efficacy of generally recognized as safe (GRAS) salts—potassium sorbate, sodium benzoate, sodium bicarbonate, and sodium tetraborate—as eco-friendly alternatives. The findings are promising. “Potassium sorbate and sodium benzoate were the most potent inhibitors, suppressing the fungus in vitro by 71% and 67% at 2,000 ppm, respectively,” Zelmat explained. These results are comparable to the commercial fungicide imazalil, which achieved 100% suppression.
The study’s in vivo trials on ‘Maroc Late’ orange fruits further validated these findings. When applied curatively, potassium sorbate and sodium benzoate reduced disease severity by 80% and 100% at a low concentration of 2% (w/v). Preventive treatments with 4% (w/v) of these salts reduced disease symptoms by up to 100%. “These GRAS salts could serve as alternatives to conventional fungicides registered for managing Alternaria diseases of citrus,” Zelmat noted, highlighting their potential to mitigate the environmental impact of current agricultural practices.
The implications for the citrus industry are substantial. With growing consumer demand for sustainably produced food and stricter regulations on chemical use, the shift toward low-toxicity alternatives is inevitable. Zelmat’s research provides a viable path forward, demonstrating that everyday food preservatives can be harnessed to protect crops without compromising safety or efficacy. As the agricultural sector continues to innovate, studies like this one will shape the future of disease management, paving the way for more sustainable and resilient farming practices.