Impact of Soil Chemical Attributes on the Behavior and Spread of Fusarium Oxysporum in Date Palm

Fusarium wilt of date palm (<i>Phoenix dactylifera</i> L.), caused by <i>Fusarium oxysporum</i> f. sp. <i>albedinis</i>, continues to threaten oases across the Maghreb. However, the disease has failed to establish in Southeastern Algeria, despite the ongoing movement of potentially contaminated plant material. This study investigated whether soil chemical properties contribute to this apparent epidemiological boundary. A total of 48 soil samples were collected from healthy and diseased date palm groves across infected (Adrar, Ghardaïa) and uninfected (Biskra) regions. Soils were analyzed for pH, electrical conductivity (EC), organic matter, calcium carbonate (CaCO₃), soluble cations (Ca²⁺, Mg²⁺, Na⁺, K⁺), and available phosphorus (PO₄ ^3-). While no consistent differences were observed between healthy and diseased trees within infected areas, five parameters-EC, Ca²⁺, PO₄ ^3-, Mg²⁺, and CaCO₃-differentiated uninfected from infected regions. Higher levels of EC, Ca²⁺, and CaCO₃ in uninfected soils suggest a suppressive effect on the pathogen or enhanced host resistance. These findings align with previous studies showing that elevated salinity and calcium can limit Fusarium development by altering cell wall integrity, enzyme activity, and spore production. Phosphorus and magnesium may further modulate disease expression through effects on plant immunity and pathogen metabolism. Our results support the hypothesis that <i>F. oxysporum</i> f. sp. <i>albedinis</i> is constrained by edaphic factors in Southeastern Algeria. This study highlights the importance of soil chemistry in shaping pathogen distributions and suggests that nutrient-based management may help suppress Fusarium wilt in date palm agroecosystems.