Blast, caused by Pyricularia oryzae, is the major disease affecting rice production worldwide. This study investigated the potential of a new silicon (Si) source to control rice blast. Plants were grown in a Si-deficient soil that received the application of calcium silicate slag (CSL) (1.5 g/kg of soil), wollastonite (W) (1.5 g/kg of soil; Goianira, Goías, Brazil), and a mixture of calcium carbonate and magnesium carbonate (control). The amount of calcium (Ca) and magnesium (Mg) were equilibrated among treatments. Blast severity was evaluated at 24, 48, 72, 96, 120, and 144 hours after inoculation on the leaves of each plant and values were used to calculate the area under blast progress curve (AUBPC). Foliar Si concentration was significantly high for CSL and W treatments (1.63 and 2.02 dag/kg, respectively) compared to control (0.45 dag/kg). There was no significant difference among treatments for foliar Ca and Mg concentrations. Many necrotic lesions with intense chlorosis and coalescence were noticed on the leaves of plants from the control treatment. The number and size of the necrotic lesions were reduced, and there were fewer lesions coalescence and much less chlorosis on the leaves of plants from CSL and W treatments. The AUBPC was significantly reduced by 73 and 48%, respectively, for CSL and W treatments in comparison to control. Silicon from Goianira´s wollastonite showed great potential to complement rice resistance against blast.