Black rot

Black rot (Xanthomonas campestris / Phytophthora palmivora) is a destructive disease affecting various agricultural crops such as crucifers (cabbage family) and cocoa. In crucifers, bacterial infection causes V-shaped yellow lesions on leaf margins that progressively turn black, rotting the vascular tissues down to the stem. In cocoa, pathogen infection manifests as rapidly expanding dark brown to black spots on the pod surface, causing the pod to harden, mummify, and destroying the beans inside.