Copper sprays are the most important measure for control of citrus canker. Mechanical wounds caused by cultural practices are entry points for the causal bacterium, Xanthomonas citri subsp. citri, and exacerbate the disease. It is not known whether additional applications would protect mechanical wounds from infection by X. citri. This study aimed to assess the predisposition of mechanical wounds to infection and the efficacy of a single copper spray applied at different times for protecting wounds against X. citri under greenhouse conditions. Access of wounds to infection was assessed by spray-inoculating a suspension of the bacterium on leaves from 0 to 7 days after wounding. Timing of a copper application was assessed by treating the wounded leaves at different points before or after bacterial inoculation and/or wounding. The incidence of wounds with citrus canker decreased over time after wounding. No lesions developed in wounds inoculated 7 days after injury. Copper sprayed at all timings reduced the incidence of citrus canker at wound sites compared to the non-treated leaves. Copper sprayed before wounding and/or inoculation showed the greatest reduction (>90%) in the incidence of citrus canker. The reduction in canker associated with wounds ranged from 91.8 to 96.1% for copper sprays applied from 24 h before to 0.5 h after wounding and inoculation, and was 67.8% when copper was applied up to 8 h after wounding and inoculation. As X. citri is splash-dispersed, we conclude that wounds need to be protected with copper sprays if rain is forecast within 7 days of a wounding event. In case no rain is expected, there is no need to protect the trees with copper. However, if trees are wounded when the canopy is wet, a copper spray should be applied before or immediately after the wounding event (but not more than 8 h later). A single appropriately timed copper spray allows the protection of wounds against citrus canker even after the tissue is injured.

喷铜是控制柑橘溃疡病的最重要措施。由文化习俗引起的机械性伤口是病原细菌柠檬黄单胞菌亚种的切入点。柠檬酸，加剧了这种疾病。尚不知道额外的应用是否能保护机械伤口免受柠檬黄杆菌的感染。这项研究旨在评估机械性伤口易感性，以及在不同时间施用单一铜喷雾剂以保护伤口免受柠檬黄单胞菌感染的功效。在温室条件下。通过在伤口受伤后0至7天将细菌的悬浮液喷雾接种在叶子上来评估伤口是否被感染。通过在细菌接种和/或受伤之前或之后在不同点处理受伤的叶子来评估施铜的时间。柑橘溃疡病的伤口发生率随着时间的推移而降低。伤后7天接种的伤口中未出现病变。与未处理的叶子相比，在所有时间喷洒的铜都减少了伤口部位柑桔溃疡的发生率。在受伤和/或接种之前喷洒的铜显示柑橘溃疡病的发生率降低幅度最大（> 90％）。从受伤前和接种后24小时到接种后0.5小时施用铜喷雾剂，与伤口相关的溃疡病减少幅度为91.8％至96.1％，伤口和接种后8 h内施用铜时为67.8％。作为X.citri是分散飞溅的，我们得出结论，如果在伤人事件后7天内预计下雨，则需要用铜喷雾剂保护伤口。如果预计不会下雨，则无需用铜保护树木。但是，如果树冠在雨天弄湿时受伤，则应在受伤事件发生之前或之后（但不超过8小时）使用铜喷雾剂。一次适当定时的铜喷雾即使在组织受伤后也能保护伤口免受柑橘溃疡病的侵害。