Despite trees being a source of medicine and herbs that treat diseases and wounds, they are also prone to infections. Like other living organisms, these diseases can be diagnosed and treated accordingly. Trees can be affected by various diseases such as bacterial, fungal, viral, parasitic, insect or nematode infections. These diseases may cause the tree's death or lead to its decline in health. Diseases that Affect Trees Here we have listed 3 of the major categories of the most common diseases that affect trees: 1) Bacterial Diseases Bacteria are one of the most common causes of plant disease. They are microscopic single-celled organisms that grow fast. The bacteria are usually found on dead leaves, bark, branches, twigs, roots, and soil. Bacterial diseases can be divided into two categories - systemic and non-systemic. Systemic illnesses spread through the entire body of the plant, while non-systemic diseases attack only specific parts of the plants. Common bacterial diseases inc