Uso do silício na nutrição da bananeira e no controle do Mal-do-Panamá

Abstract

The banana crop is extensively cultivated in tropical regions, usually by small farmers, hence its economic and social importance. However, Panama disease, caused by Fusarium oxysporum f. sp. cubense (Foc), is known as one of the most destructive banana diseases in the world. It is accounted for tremendous losses to banana producers; therefore, alternatives other than genetic resistance are especially necessary. Silicon (Si) has been shown to provide effective control of fungal plant diseases but so far its effect on banana plants and Foc is not completely understood. In that sense, our objectives were: 1) evaluate the absorption and translocation of silicon in banana, and 2) evaluate the effect of increasing doses of silicate on the resistance of different banana cultivars to Panama Disease. The addition of increasing doses of Si to the soil corrected soil acidity and changed nutrient (calcium, magnesium and silicon) availability as well as increased phosphorus levels in the soil. Moreover, to the dry matter of banana roots and shoots was increased. Plants supplied with Si showed higher concentration of potassium, calcium, magnesium and silicon and reduction of nitrogen and phosphorus in the shoot. Banana plants absorbed and translocated silicon to the shoot and seem to behave as an intermediate Si accumulator. Severity of Panama Disease symptoms in this study was negatively correlated to increasing doses of silicon added to the soil.