1. Decay of roots. A fairly common disease in this flower. Blackening and wilting of leaves are direct signs. This is due to the amount of moisture in the soil. The plant should be transplanted and the decayed roots should be cut off. Perform the procedure with gloves on.
2. Fall of young leaves. This is most often due to low room temperatures, drafts or dry air. Carefully review the growing conditions for your pet.
3. Black spots on the plant. This is a direct sign of fungal diseases, most often due to the high percentage of moisture. Watering should be reduced, for a while, stop spraying the flower, and it is imperative to treat the entire plant with a fungicide preparation.
4. Dark spots on the leaves. This problem occurs due to direct sunlight falling on the leaves, they cause strong ooi. Move the dieffenbachia to partial shade, and cut off the damaged leaves.
5. Brown spots on the tips of the leaves. This factor speaks of a very dry soil. The damaged parts must be cut off (use gloves) and the plant must be watered sufficiently.