SOIL CHEMICAL CHARACTERISTICS IN RELATION TO FUSARIUM WILTS IN BANANACROPS OF GRAN-CANARIA ISLAND (SPAIN)

Several soil characteristics have been studied in relation to Fusarium wilts in field plots of banana plantations of Gran Canaria Island (Sp ain). Principal component analysis has been applied to soil chemical p arameters, the aim being to determine the possible relationships betwe en the apparition and development of the Fusarium wilts and soil chara cteristics. The results seem to indicate that there is a relationship between the disease incidence and the values of some parameters like p H, cation exchange capacity (CEC), sodium (Na) in solution, and iron ( Fe); pH, CEC, and Na values were significantly smaller in areas affect ed by the disease. However, the values of Fe extracted with DTPA and F e associated with fulvic acids were significantly higher in disease af fected areas; the same tendency was observed in the values of total ca rbon (C) and nitrogen (N) in the different areas. Other parameters stu died, like exchangeable cations, Fe-oxalate, etc., have not showed eit her differences or general tendencies. These results seem to suggest t hat the absence and/or presence of disease could be controlled partly for the chemical characteristics of the different soil areas of the sa me field plot.