Pectobacterium caratovorum subsp. cacatovorum (Pcc) is one of the most important plant pathogens that cause a wide range of symptoms, such as soft rot in a wide range of plants. So in this work to control these pathogens, silver nanoparticles (NPs) were prepared by marigold flower extract using silver sulfate salt, for the first time. There are several ways to produce silver NPs; but, the use of plants in the synthesis of NPs has received much attention in recent years due to low cost, high production speed, efficiency, and environmental compatibility. The prepared silver NPs were characterized by UV–visible (UV–vis) spectroscopy, Fourier transforms infrared (FT-IR) spectroscopy, X-ray diffraction (XRD) and Energy Dispersive X-ray Spectroscopy (EDS). Field Emission Scanning Electron Microscopy (FESEM) was used to determine the morphology and size of the NPs. Also, their antibacterial effect was evaluated by three methods of determining the minimum inhibitory concentration (MIC), the minimum bactericidal concentration (MBC) and biofilm inhibition against Pcc. The present study showed that the green method produced uniform silver NPs with small size and antibacterial properties. It also showed that silver NPs synthesized due to the different chemical structure of silver sulfate salt have a weaker antibacterial effect than similar NPs synthesized from other silver salts. The MIC and MBC records were 40 and 160 ppm, respectively. The NPs showed a bimodal effect on biofilm formation as the lowest biofilm formation achieved in 2.5 and 40 ppm, respectively.

副杆菌芽孢杆菌亚种。卡卡托沃鲁姆（Pcc）是引起多种症状（例如多种植物的软腐病）的最重要的植物病原体之一。因此，在这项控制这些病原体的工作中，万寿菊花提取物首次使用硫酸银盐制备了纳米银颗粒。有几种生产银纳米颗粒的方法。但是，近年来，由于成本低，生产速度快，效率高和环境相容性好，在NP的合成中使用植物已引起了广泛的关注。制备的银纳米颗粒通过紫外可见光谱，紫外傅立叶变换红外光谱，X射线衍射（XRD）和能量色散X射线光谱（EDS）进行表征。场发射扫描电子显微镜（FESEM）用于确定NP的形态和大小。也，PCC。目前的研究表明，绿色方法可生产出具有小尺寸和抗菌特性的均匀银纳米颗粒。这也表明，由于硫酸银盐化学结构的不同而合成的银纳米颗粒比由其他银盐合成的类似纳米颗粒具有更弱的抗菌作用。MIC和MBC记录分别为40和160 ppm。NP显示出对生物膜形成的双峰效应，因为最低的生物膜形成分别达到2.5和40 ppm。