Blackspot is a plant disease of black blotches, leaf loss and rotting from bacterial or fungal infection. It also denotes handling injury to plant foods such as potatoes, where bruising shows as black patches beneath the skin. Both forms downgrade appearance, shelf life, and marketability, though only the pathogenic form spreads between plants. Prevention combines field disease management, including resistant varieties and fungicide programmes where appropriate, with gentle harvesting, proper curing, and careful handling to minimise the bruising that later appears as dark blemishes in stored crops.