Phytophthora

Phytophthora is a disease that is present mainly found in the substrate and is very aggressive,  as it can kill a tree with great longevity. 

Phytophthora species were originally grouped with fungi due to similarities in morphology and lifestyle but are now considered to be in a separate classification called oomycetes.

It is a soil organism that develops in tissues, is very resistant and behaves differently depending on the soil, temperature and oxygen conditions.

The infection of the plant begins in the roots, once the plant is affected it develops a rot or foliar necrosis in its root system that expands to the stem and neck of the plant. The attack is more frequent after germination. In adult plants, blackened roots are observed, and both the stem and the leaves turn yellow and wilt. This disease prevents the free circulation of sap, in addition, with necrotic roots, the plant does not assimilate the free water from the soil, generating a rapid wilting in the plant.

Identifying the symptoms is not easy, since at first it may seem that only the plant requires water and when trying to improve the situation it only improves the living conditions of this organism, generating the death of the plant

The first symptoms are observed in the leaves, after that they occur on the stems or on the entire branches.

There are different species of this disease, so it affects each plant differently, despite that some characteristic symptoms that most crops have are:

- Progressive drying of the branches. 

- Leaves may turn dull green, yellow, or in some cases red or purplish. 

- Trees develop darkened areas in the bark around the crown and upper roots. 

- Gum or dark sap may ooze from the margins of the diseased trunk area.

- Amber gummy secretion, better known as gummy.

- No mycelium (slender filaments of a fungus body) is visible in between the bark and wood.