Hydrogel-Based Controlled Release of Phytohormones: Improving Bioavailability and Early Plant Development Outcomes

The application of hydrogels in agriculture has gained increasing attention for its potential to support early plant development, a stage highly sensitive to environmental and biochemical fluctuations. This review examines the role of hydrogel-mediated delivery of plant-derived bioactives, particularly phytohormones, in regulating their availability during seed germination and seedling establishment. Evidence from recent studies shows that hydrogels function as three-dimensional polymeric matrices that enhance water retention and provide controlled delivery of encapsulated phytohormones. These properties are consistently associated with improved germination, root development, stress tolerance, and early plant establishment. Importantly, hydrogel-based systems regulate the timing, localization, and duration of phytohormone exposure, contributing to improved developmental responses while reducing losses and phytotoxic effects associated with conventional applications. Overall, this work highlights the need for further field-scale studies to determine how controlled release strategies can be leveraged to optimize plant development under realistic agricultural conditions.