Synthesis of copper (II) citrate and evaluation of its in vitro antifungal and antibacterial activities, and the suitability of using this chemical as a plant protection agent

Abstract

In this paper, copper (II) citrate Cu₃(C₆H₅O₇)₂ was successfully synthesised in an aqueous solution. The factors for the synthesis process such as temperature and molar ratio of the reactants were investigated. The structural, properties and composition characteristics of the elements were investigated and evaluated by X-ray diffraction pattern (XRD), Fourier-transform infrared spectroscopy (FTIR), energy-dispersive X-ray spectroscopy (EDX), and UV-Vis spectroscopy. The yield of the copper (II) citrate in the reaction was 82.46% at the molar ratio of the CuSO₄/C₆H₅Na₃O₇ of 1.5/1 at 70^oC. The in vitro results showed that copper (II) citrate at a concentration of 1,000 ppm inhibits the mycelial growth of Sclerotium rolfsii and Fusarium oxysporum with control values ranging from 19 to 53% after 2 days of incubation. Besides, it strongly suppressed the plant bacterial pathogens Xanthomonas axonopodis (bacterial strain causing citrus canker), Ralstonia solanacearum (bacterial wilt of tomato), and Clavibacter michiganensis subsp. michiganensis (cause of bacterial wilt and canker of tomato). These results suggested that copper (II) citrate can be used as a promising fungicide/bactericide to control fungal and bacterial diseases on citrus and tomato plants.