As the name suggests, symptoms can be described by leaf deformation. The initial curling begins on the lower leaves and rolls upward followed by an inward curl lengthwise. Usually, they will recover if environmental conditions and cultural factors are adjusted to reduce stress. The leaves can appear paler, stunted, with yellow edges or purplish veins on the lower side.
The physiological disorder of leaf curling occurs due to environmental stress. Excessive moisture and high nitrogen levels are the main causes of leaf deformation, in addition to heat, dry conditions, severe pruning, root damage, and transplant shock. Leaf curling symptoms are also found and might be confused with viral infections. For example, whiteflies transmit a virus (Yellow Leaf Curl Virus - YLCV) that causes new leaves to become cupped.
No biological treatment is known against this physiological disorder. It can only be treated with preventive measures.
Always consider an integrated approach with preventive measures together with biological treatments, if available. This physiological disorder can only be treated with preventive measures.