Rosellinia bunodes is the causal agent of black root rot of many herbaceous and woody perennials in both tropical and sub-tropical regions of the world.

[2][3] Species in the genus Rosellinia can be microscopically identified by the characteristic pear-shaped (piriform) swelling near the septa of adjacent hyphal cells.

[2] Rosellinia bunodes is a facultative soil saprophyte capable of infecting a wide range of hosts, including native forest species and important agricultural crops like tea, citrus, coffee, yam, fig, rubber, cassava, banana, avocado, pepper, potato, cocoa, ginger, daffodils, yerba mate and poplar.

[3] As mycelia grow, they form dense mats over roots and at the base of tree trunks that thicken into irregular knots and aggregate into rhizomorphs.

[1] Rosellinia bunodes' mycelia can also aggregate and extend through the soil as rhizomorphs to cause new infections on nearby susceptible hosts.

[4] The saprophytic nature of R. bunodes allows the fungus to survive easily without a host, and the pathogen can increase inoculum by colonizing dead or felled trees and stumps with large underground root masses.

[3] Even though R. bunodes has only been found in tropic and sub-tropic environments, it is distributed worldwide with outbreaks occurring mainly in the Americas, Africa, India, Indonesia, the Philippines, and Sri Lanka.

[3] Considered an opportunistic root pathogen, R. bunodes typically infects plants that are already stressed from abiotic and/or biotic factors such as nematode or insect attack and poor soil nutrient levels/availability.

[4] Removal of crop residue, dead or felled trees, and in situ burning of stumps have likewise shown to be helpful in preventing the build-up of inoculum.

Fungicide treatments usually include broad-spectrum approaches such as metam sodium, benzimidazoles, chlorophenyls, imidazole, morpholine, oxathiin, triazoles, and some inorganic compounds.

[4] Some research has shown biocontrols using mycorrhizal or mycoparasitic fungi (i.e.: Trichoderma spp., Clonostachys spp., Glomus manihotis, and Entrophospora colombiana) to be effective in suppressing the disease, but it is not clear if these interventions are successful only in certain environments or in specific host-pathogen combinations.