Enhancing Cabbage Palm resilience to saltwater stress through silicon applications

Authors: GONZALEZ, PEDRO - Florida International University; TUCKER, DANIEL - Florida International University; Nageswara Rao, Madhugiri; GRIFFITH, PATRICK - Montgomery Botanical Center; BASKAR, MARUTHI - Florida International University; ROSS, MICHAEL - Florida International University; KHODDAMZADEH, AMIR - Florida International University

Submitted to: HortScience
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/30/2025
Publication Date: 8/19/2025
Citation: Gonzalez, P., Tucker, D.A., Nageswara Rao, M., Griffith, P., Baskar, M., Ross, M., Khoddamzadeh, A. 2025. Enhancing Cabbage Palm resilience to saltwater stress through silicon applications. HortScience. 60(9):1547-1554. https://doi.org/10.21273/HORTSCI18718-25.
DOI: https://doi.org/10.21273/HORTSCI18718-25

Interpretive Summary: This cover page journal article "Enhancing Cabbage Palm Resilience to Saltwater Stress through Silicon Applications" interprets the threat of saltwater intrusion from sea-level rise on Florida's coastal ecosystems and investigates a practical mitigation strategy using silicon. The study demonstrated that while high salinity severely impairs the growth and survival of one-year-old cabbage palm (Sabal palmetto) seedlings, the application of soluble silicon effectively buffers the negative effects. Specifically, silicon markedly reduced the losses in chlorophyll content and stem growth under moderate saline conditions (up to 30 ppt) and provided some protection even under hypersaline conditions (50 ppt), though it could not prevent poor overall survival at the highest levels. This indicates that silicon can raise the salt-tolerance threshold of young palms, providing an actionable strategy for nursery production and restoration efforts to improve the physiological status and resilience of this ecologically and economically important species in the face of accelerating ecological changes.

Technical Abstract: Saltwater intrusion driven by ecological changes increasingly imperils Florida’s coastal ecosystems. This study investigated whether silicon amendments can buffer cabbage palm (Sabal palmetto) seedlings against saline stress. One-year-old seedlings were irrigated with seawater analogues at 10, 30, or 50 ppt (ranging from freshwater to hypersaline conditions) and supplemented with soluble silicon at 1%, 3%, or 5% (m/v). Vigor was quantified nondestructively using SPAD-502 and atLEAF+ meters that estimated the chlorophyll content and measurements of height and leaf number. Salinity alone decreased all growth variables, with the steepest declines observed with 50 ppt. Silicon markedly mitigated losses in chlorophyll content, height, and leaf production at 10 through 30 ppt and partially preserved performance at 50 ppt; however, overall survival remained poor at the highest salinity. The results revealed a low inherent salt-tolerance threshold during early ontogeny; however, they demonstrated that silicon can extend that threshold and improve the physiological status under moderate intrusion scenarios. These findings furnish actionable guidance for nursery production and restoration of cabbage palm as the rise in sea level accelerates saltwater encroachment in Florida’s coastal landscapes.