Phytophthora
Phytophthora is a pseudofungus (oomycetes, such as pythium), which affects numerous ornamental and agricultural species (palms, citrus, oak, cuprusaceae, conifers and eucalyptus). They tend to proliferate in moderate temperature conditions (15-30ºC), such as spring or autumn, especially in areas with high soil moisture, flooded or with very high groundwater levels. The main symptom is the drying of the most distal areas of the crown, which will not be able to receive enough water and nutrients because the root loses absorption capacity due to the action of the pathogen.