YaraVita ACTISIL, organically stabilised silicon for foliar spraying. YaraVita ACTISIL's active ingredient is organically stabilised (ortho) silicic acid, which is the plant's source of silicon. Because it has been stabilised, the (ortho) silicic acid will remain easily absorbable by plants. Consequently, a low dose of this foliar fertiliser will sufficiently cover the plant's need. Studies have shown that the application of silicon as a fertiliser can improve crop quality (examples are fruit firmness and shop shelf life), improve yield, and can promote resistance against physical stressors (heat, drought).