Bài báo khoa học

In this study, copper carboxylate (C 17 H 33 COO) 2 Cu (copper (II) oleate) was successfully synthesized in an aqueous solution. The factor for the synthesis process is the molar ratio of the reactants. The structural, morphological and composition characteristics of the elements were investigated and evaluated by Fourier-transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDX) and UV-Vis spectroscopy. The yield of the copper (II) oleate in reaction was 90.4 % at the molar ratio of the CuSO 4 /C 17 H 33 COONa of 1:3. The test microorganisms Xanthomonas axonopodis (bacterial strain causing citrus canker) and Colletotrichum spp. (fungal strain causing anthracnose) in this study were isolated from diseased fruits of Vinh orange trees, which was cultivated in Nghe An province. The results of the study show that the obtained copper carboxylate product has strong inhibition agaisnt X. axonopodis and Colletotrichum spp in vitro. The antibacterial effects of copper (II) oleate at concentrations of 1000 and 500 ppm were completely inhibitory against X. axopopdis and other bacterial pathogens including Ralstonia solanacearum (causal of wilt of tomato) and Clavibacter michiganensis (causal of canker of tomato). At a concentration of 1000 ppm, the inhibitory effect of copper (II) oleate on Colletotrichum spp. reached over 50 % after 2 days of culture. These results suggested that copper carboxylate can be used as a promising fungicide/bactericide to control canker and anthracnose diseases in the orange crops growing in Vinh as well as in a variety of citrus species and other crops. The product also could be considered as an alternative to harmful synthetic fungicides and bactericides.