Vascular fusariosis of the date palm (Phoenix dactylifera L.) caused by Fusarium oxysporum f. sp. albedenis (Foa). It is considered to be one of the most serious diseases, posing a permanent threat to North African palm groves, and has caused the disappearance of 20 million palm trees, including three million Algerian palm trees, since it first appeared in 1870. A collection of isolates representative of the diversity of Foa populations from symptomatic...