Curl is a physical distortion of plant foliage, usually caused by viral infections, fungal pathogens, or severe aphid feeding. The affected leaves roll inward or pucker tightly, which reduces the photosynthetic area and stunts the plant's overall growth. In historic contexts, it specifically referred to potato leafroll virus, a devastating disease that wiped out entire harvests before certified seed programs existed.
Heard on the job
We've got a bad case of peach leaf curl on the early varieties, so we need to hit them with copper fungicide once they drop their leaves.
Also heard as
- leaf curl
Do not mix it up with
- Curly top: Curl is a general symptom of many pathogens, while curly top is a specific viral disease transmitted by leafhoppers.