January 2017. A photo of lesions on a lime leaf from the Sudan. The email was sent via Dr Stephan Winter of the German Collection of Microorganisms and Cell Cultures, Braunschweig. The disease is new in the area, and serious.
Members suggested that the image (top, left) was showing symptoms of citrus canker, Xanthomonas citri.
Later, a member from Gezira University sent photos (rows 2 & 3) from Sinnar State, near the centre of Sudan. He mentioned that researchers there "noticed the prevalence of scale insect on the lime trees prior to the appearance of the bacterial canker symptoms". However, the trees recovered when the scale was controlled, and "nothing happened with the application of bactericides".