Diseased Plants: Black Leaves and Sooty Mould

2024-07-17 Gallura Disinfestazioni posted:

The superficial blackening of the leaves and trunks of plants is due to a disease that is found in many plant species, sooty mold.

Sooty mold appears as a dark blackish veil with a dusty appearance, resembling soot, hence the name "sooty mold".

Sooty mold is made up of various fungal microorganisms that are found in correspondence with the honeydew produced by insects, such as aphids, whiteflies and scale insects that use the sugary substances contained in the honeydew for their growth.

The fungal agents that cause sooty mold are saprophytes that do not directly infect the plant, but develop on its surface, feeding on the sugary substances naturally emitted by the tree or often on the honeydew produced by scale insects.

The presence of scale insects and conditions of high humidity, due to the climate or incorrect management of the foliage, favor infestations, which in fact occur especially in the autumn-winter period.

Sooty mold indirectly damages the affected plants by covering the leaves and trunk with a dark patina that reduces their photosynthetic activity and weakens them, making the plants sick.

The damage caused by sooty mold can therefore be considered indirect: the blackish patina on the leaves causes a reduction in the photosynthetic capacity and gas exchanges. When a large portion of the crown is affected, the tree can grow poorly, as well as decreasing its productive capacity.

Furthermore, this coating causes aesthetic damage to the plants and fruit, which must be cleaned before being consumed. Leaves, shoots, twigs and fruit of many herbaceous and arboreal plants are affected. The development of sooty mold is favored by high humidity and high temperatures.

The maintenance of the lawn, plants and our entire garden is crucial.

It is therefore essential to adopt defense strategies aimed at removing factors favorable to the development of sooty mold and improving the vegetative conditions of the plant in order to prevent future infestations.

The technicians of Gallura Disinfestazioni carry out a careful analysis of the infested plants to plan the best control and/or prevention plan to protect the health of the plants.