ObjectiveTo evaluate the effect of Si fertilization on the growth and yield of common garlic under semi-arid cultivation conditions.MethodsTwo field experiments were conducted simultaneously in Mossoro and Sao Miguel, Rio Grande do Norte, Brazil. The experiment was arranged in a randomized block design, in a 2 x 5 factorial scheme, with two sources of Si (calcium and potassium silicate) and five doses (0, 2, 4, 6, and 8 kg ha-1) applied via foliar.ResultsApplying Si doses promoted increased height, dry mass, and yield of common garlic in Mossoro and Sao Miguel. The effect of Si doses on garlic was independent of the sources used since there was no significant effect for this factor on all variables. In Mossoro, the plants reached maximum height (51.38 cm) at the dose of 4.6 kg ha-1 of Si, higher accumulation of leaf dry matter (3.84 g per plant), bulb (4.53 g per plant) and total (8.37 g per plant) with 4 kg ha-1 of Si and higher commercial (2.72 t ha-1) and total (3.95 t ha-1) yield of bulbs at the doses of 4.1 and 4.4 kg ha-1 of Si, respectively. In Sao Miguel, the plants reached the highest height (57.09 cm) and total dry matter accumulation (9.74 g per plant) with 2.9 kg ha-1 of Si, maximum accumulation of bulb dry matter (7.10 g per plant) with 2.6 kg ha-1 of Si and higher values of commercial (6.62 t ha-1) and total (6.64 t ha-1) productivity applying 3.5 and 3.9 kg ha-1 of Si, respectively.ConclusionsThe foliar application of Si improves the growth and yield characteristics of common garlic bulbs grown in a semi-arid region. Using different sources of Si does not influence the growth and yield of common garlic.