Seed-Predating Insects and Dormancy Overcoming in Tachigali vulgaris

Tachigali vulgaris is a native tree species widely distributed throughout the Brazilian Cerrado, with considerable economic potential and ecological importance. However, its cultivation remains limited because of physical seed dormancy, which restricts germination and seedling production, as well as seed predation by insects. Therefore, this study aimed to report seed-predating insects associated with T. vulgaris, including the first record of a seed beetle species for the Cerrado biome and the state of Goiás, Brazil, and to evaluate the effectiveness of different dormancy-breaking methods to determine the most effective approach for nursery propagation. Five pre-germination treatments were evaluated: untreated control, puncture with an electric drill, fire exposure for 60 s, seed coat nicking with pruning shears, and mechanical scarification with electric sandpaper on the side opposite the hilum. Seed germination, germination speed index (GSI), and seedling performance were assessed. Two seed beetle species (Chrysomelidae, Bruchinae), Stator limbatus and Amblycerus marinonii, were identified, with S. limbatus representing the first record for the Cerrado biome. Untreated seeds exhibited pronounced physical dormancy, with only 12% germination and 86% hard seeds. Puncture showed the highest performance (94% germination; GSI = 11.6), followed by mechanical scarification (84%; GSI = 11.4) and seed coat nicking (76%; GSI = 11.1). Fire treatment was ineffective, resulting in low germination (9%; GSI = 2.9) and high seed mortality (23%). Seedlings derived from punctured seeds also showed greater growth and dry mass. These findings demonstrate that puncture is the most effective method for overcoming seed dormancy in T. vulgaris, whereas fire treatment is not recommended under the conditions evaluated.