Gummosis disease of citrus is caused by a fungal infection.
Gummosis is a plant disease that affects citrus trees, among others. The disease causes a variety of symptoms, including oozing or bleeding of sap from the trunk or branches, as well as the formation of gum-like lesions on the bark. In severe cases, gummosis can weaken the tree and make it more susceptible to other infections or stressors.
The disease is caused by several species of fungi, which infect the bark and wood of the tree. The fungi are often introduced into the tree through wounds or other damage to the bark, and they can then spread through the tree's vascular system. As the fungi grow and reproduce, they cause the tree to produce excessive amounts of sap or gum in an attempt to defend itself.
Overall, gummosis disease of citrus is caused by a fungal infection that can damage and weaken citrus trees if left untreated.