Phytophthora palmivora is an oomycete that causes bud-rot of palms, fruit-rot or kole-roga of coconut and areca nut.

Sporangia germinate directly in a nutrient medium by producing germ tubes that develop into mycelial masses.

In the presence of nutrients, chlamydospores germinate by producing germ tubes that continue to grow and form mycelial masses.

Zoospores are capable of long-term survival but do not play a significant role in the disease cycle because sexual reproduction requires the presence of opposite mating types, and the chance for this to occur in nature is very low.

[citation needed] During rainy periods, chlamydospores in soil may germinate in water to produce sporangia and release zoospores.

Chlamydospores formed in fallen fruit survive in soil and serve as the main source of inoculum for infection of roots of papaya seedling in subsequent plantings.

[citation needed] Favorable temperature is also a contributing factor to the severity of Phytophthora diseases because of its effect on growth and sporulation of the pathogen.

One common symptom of P. palmivora is fruit rots which are found in papaya, citrus, coconuts, durian, and cacao.

Root rots are another symptom of P. palmivora and can be seen in red maples, citrus, papaya, mango, durian, and black pepper.

The signs of P. palmivora are microscopic and can be differentiated from other oomycetes by the presence of oval shaped papillate sporangia with short pedicles and spherical oogonia with narrow stalks (Widmer, 2014).

Rain splash is needed for liberation of sporangia of P. palmivora from the surface of infected fruit into the atmosphere and for projection of the soil inoculum into air.

[citation needed] Since P. palmivora is an oomycete the simplest management technique is to control the amount of water present in the soil.

Other means of cultural control for P. palmivora include mulching to reduce the number of spores released via rain splash, complete removal of infected host plants and materials, and in some cases the use of companion crops.

[citation needed] Root rot of papaya seedlings, caused by P. palmivora, in replant fields can be controlled with the virgin soil technique.

Incidence of Phytophthora root rot of mature trees in waterlogged areas during the rainy periods can be greatly reduced by improving drainage in the orchards.

[5]: 126 Because P. palmivora infects multiple hosts that hold an economic significance including cacao, coconut, papaya, mango, olive trees, and black pepper, this is a pathogen of great concern.