Main fungal diseases:
The same fungal diseases that occur in the garden generally develop on the terrace. One of the most easily manifested is oidium; it is a fungus that attacks the upper page of the foliage, causing large white spots, similar to flour or icing sugar; over time the spots darken and curl the leaf page. This type of disease develops preferably in spring, and is favored by the presence of moisture on the foliage; to prevent the development of powdery mildew it is generally sufficient to avoid watering the plants in the aerial part when the daily temperature range is high. In periods with cool nights and high rainfall oidium tends to develop easily, it is cured using sulfur-based fungicides. Another very common fungal disease is the fumaggine, caused by fungi that colonize the honeydew percolated on the foliage by insects, such as aphids or cochineal; generally taking care of the plants affected by insects in a timely manner prevents the possibility of fumaggini developing; if they develop sometimes it is sufficient to clean the foliage with a microfibre cloth, but in the case of widespread development of the disease it is advisable to carry out treatments based on copper. The other fungal diseases that develop easily are gray mold (botrytis), and root or collar rot; these are molds and spots that develop at the base of the plant or on the foliage, with consequent rapid deterioration of the whole plant; generally the development of these types of mushrooms is highly favored by environmental conditions and unsuitable cultivation methods. The rots develop preferably in asphyxiated, damp soils with stagnant water; therefore correct waterings prevent the development of such pathologies. Lack of ventilation, high environmental humidity and excesses of sulfur-based fertilizers favor the development of botrytis, the main cause of gray mold.