SPRING SUMMER BONUS MAGAZINE 2026

Beyond application: Activating calcium utilisation with KELPURA™ KELPURA™ (Fertilizer Group 3, M442) is a concentrated kelp-derived biostimulant from Ecklonia maxima, produced through a low-temperature extraction process to retain its full spectrum of bioactive compounds. These include phytohormones, phenolic acids, salicylic and benzoic acid-related compounds, and amino acids, all of which act together to improve the plant’s ability to absorb, transport, and structurally utilise foliar-applied calcium during reproductive development. In calcium programmes, particularly in combination with CALCINATOR™ (Fertilizer Group 2, B5022), KELPURA™ functions as the physiological driver that determines whether applied calcium becomes functionally integrated into plant tissues. The effectiveness of this system is defined by how KELPURA™ interacts with the plant processes that normally limit calcium utilisation (Figure 1). Calcium is essential for cell wall stabilisation, membrane integrity and reproductive development, yet it is inherently immobile within the plant and cannot be redistributed to actively growing tissues such as flowers and fruit (White & Broadley, 2003; Marschner, 2012). As a result, these tissues depend on continuous external supply through foliar application. However, applied calcium only becomes functional if it remains mobile, reaches developing tissues, and is incorporated into the cell wall. KELPURA™ improves this efficiency by acting directly on each of these steps through its integrated biochemical composition. Figure 1: Mode of action of KELPURA™ on calcium uptake and utilisation. plication: Activating calcium with KELPURA™ applic Spring/Summer 2026 BONUS www.agribonus.co.za 128