Xanthomonas citri subsp. citri is a plant bacterium that causes citrus canker, an important disease in several citrus-growing areas. Due to its relevance, this pathosystem has been frequently investigated, requiring suitable protocols of inoculation for symptom reproduction. This study aimed to evaluate the effect of the concentration of X. citri and the duration of the moisture chamber period on the incidence and severity of citrus canker symptoms under greenhouse conditions. Inoculum concentrations ranging from 10⁰ to 10⁸ cfu/mL were evaluated using both infiltration and spray-inoculation methods. The effect of the moisture chamber on the development of citrus canker lesions was assessed for 24 or 48 h before and/or after inoculation. The minimum concentrations required to infect 100% of the inoculated leaves using infiltration and spray-inoculation were 10⁴ and 10⁷ cfu/mL, respectively. Intermediate severity levels, e.g., 3.2 to 11.4 and 2.5 to 6.7 lesions/cm², were observed using 10³ – 10⁴ cfu/mL for infiltration and 10⁶ – 10⁷ cfu/mL for spray-inoculation. This severity level is suitable when the number of lesions in a given treatment needs to be determined. Conversely, lower or higher inoculum concentrations resulted in severities either extremely low, with no or very few lesions, or excessively high, with coalesced lesions forming a large necrotic area, respectively. A moisture chamber period of 24 h after spray-inoculation was sufficient for reproducing citrus canker lesions under greenhouse conditions. Suitable inoculum concentrations and the use of a moisture chamber after spray-inoculation of X. citri are critical for the successful reproduction of citrus canker symptoms.

柑橘黄单胞菌亚种 柑橘是一种引起柑橘溃疡病的植物细菌，柑橘溃疡病是一些柑橘种植区的一种重要疾病。由于其相关性，该病理系统已被频繁研究，需要合适的接种方案来重现症状。本研究旨在评估温室条件下柑橘溃疡病菌的浓度和潮湿室持续时间对柑橘溃疡病症状的发生率和严重程度的影响。 使用渗透和喷雾接种方法评估10 ⁰至10 ⁸ cfu/mL范围内的接种浓度。在接种前和/或接种后 24 或 48 小时评估湿度室对柑橘溃疡病病变发展的影响。使用渗透和喷雾接种感染100%接种的叶子所需的最低浓度分别为10 ⁴和10 ⁷  cfu/mL。^{使用 10 3} – 10 ⁴  cfu/mL 进行浸润，使用 10 ⁶ – 10 7 cfu/mL 进行喷雾接种，观察到中等严重程度，例如 3.2 至 11.4 和 2.5 至 6.7 个病灶/ ^{cm 2}  。当需要确定给定治疗中的病变数量时，该严重程度是合适的。相反，较低或较高的接种浓度分别导致严重程度极低（没有或很少有病变）或过高（合并病变形成大的坏死区域）。喷雾接种后 24 小时的潮湿室时间足以在温室条件下再现柑橘溃疡病斑。喷雾接种柑橘溃疡病菌后合适的接种浓度和湿度室的使用对于柑橘溃疡病症状的成功繁殖至关重要。