Soil attributes, plant nutrition, and Fusarium wilt of banana in São Paulo, Brazil

Abstract

Fusarium wilt of banana (FWB), caused by Fusarium oxysporum f. sp. cubense (Foc), is the most destructive banana disease in Brazil. Different epidemic rates of FWB are commonly observed in certain plots of monocrop plantations suggesting that factors suppressing or boosting the disease are in place. The identification and management of predisposing factors to FWB offer a pathway to better management practices and reduced yield losses. In this study, chemical and physical soil attributes and the nutritional status of plants in Foc infested (Foc+) and healthy (Foc−) plots in two contrasting banana production systems in Sao Paulo, Brazil, were analyzed. Nine farms placed in Vale do Ribeira (VR; N = 5) and Sao Bento do Sapucai (SBS; N = 4) were assessed. In VR, where more chemical fertilizers are used, FWB was associated with higher soil acidity and lower levels of phosphorous (P), calcium (Ca), and manganese (Mn). In addition, lower values of base saturation were found in Foc+ than in Foc− plots. In SBS, where chemical fertilizers are rarely used, soil chemical attributes were not associated with FWB, except boron (B), which showed lower values in Foc+ than in Foc− plots. However, physical attributes (bulk density and penetration resistance) showed higher values in Foc+ than Foc− plots in SBS. These attributes were not associated with FWB in any of the VR’s farms. Our data also suggest that FWB can significantly affect the plant’s nutritional status. Cations (Ca and K) and their ratios with nitrogen (N) were lower in plant leaves from Foc+ than from Foc− plots in both production systems. The impact of soil management practices on FWB intensity and the need for site-specific approaches to better understand and support disease management strategies are discussed.