Application of Gellan Hydrogel and Kaz-6 in Wheat Seed Coating for Improved Productivity and Environmental Resilience
Bagila G. Tursynova, Tolganay Zharkynbek, Rauash Mangazbayeva, Nurzhan Mukhamadiyev, Raushan B. Koizhaiganova, Gulnaz Mengdibayeva, Assel Ten, Bayana B. Yermukhambetova, Grigoriy A. Mun, V. К. Yu
Abstract
Drought is a major environmental constraint that negatively affects crop germination, seedling establishment, and overall yield. This study presents a sustainable approach to improving wheat productivity under water-deficit conditions through the application of a gellan gum-based hydrogel enriched with the growth stimulant. The hydrogel was synthesized by inducing ionic gelation of gellan gum using potassium chloride and ammonium sulfate, forming a robust, cross-linked polymer network. Wheat seeds were coated with one to eight layers of the hydrogel using a sequential dipping and drying process. Optimal seedling performance was achieved with a two-layer coating, balancing sufficient water retention with adequate gas exchange. FTIR spectroscopy and pH analysis confirmed ionic interactions between Kaz-6 and the carboxyl groups of gellan, supporting its stable incorporation within the polymer matrix. Mechanical characterization showed that ammonium sulfate significantly enhanced gel strength and cross-linking density compared to potassium chloride. Laboratory germination assays and greenhouse trials demonstrated that seeds coated with gellan hydrogel containing Kaz-6 showed enhanced germination rates, greater biomass accumulation, and significantly improved drought tolerance-surviving up to 10 days longer than controls under water-limited conditions. These findings highlight the potential of biopolymer-based hydrogels as eco-friendly seed coating materials that can improve crop resilience and productivity in arid environments. The proposed formulation aligns with sustainable agriculture goals and represents a promising direction for future field-scale applications in climate-adaptive farming systems.