DESENVOLVIMENTO DE MUDAS DE EUCALIPTO COM O USO DE HIDROGEL Á BASE DE GOMA DE CAJU E MESOCARPO DE BABAÇU

Abstract

The use of hydrogels in forest seedling production has gained prominence for increasing soil water retention and mitigating the effects of water deficit, thereby aiding plant establishment under conditions of low water availability. In this context, hydrogels derived from natural polymers offer a sustainable alternative to commercial polyacrylamide-based products. This study aimed to evaluate the efficiency of biodegradable hydrogels produced from cashew gum (*Anacardium occidentale*) and babassu mesocarp (*Attalea speciosa*) on the early development of eucalyptus seedlings under varying levels of water availability. The experiment was conducted in a greenhouse using a randomized block design in a 3 × 4 factorial arrangement with three replicates, testing two natural hydrogels, one commercial hydrogel, and four water availability levels (0%, 25%, 50%, and 100% of pot water-holding capacity). Parameters evaluated included height, stem diameter, fresh and dry mass of shoots and roots, root volume, and the Dickson Quality Index. Results showed that water availability levels significantly influenced seedling growth; the best performance—characterized by improved biomass accumulation and plant quality—was observed at 50% of the water-holding capacity. The natural hydrogels performed similarly to the commercial hydrogel, with no significant differences among the treatments. It is concluded that hydrogels based on cashew gum and babassu mesocarp have the potential to replace commercial hydrogels in eucalyptus seedling production, offering a biodegradable, lower-cost, and more environmentally sustainable alternative for water management in forest nurseries.