Fungal and plant extracts improve germination and early development of Urochloa brizantha

Urochloa brizantha is widely used in tropical livestock systems, but its seeds often germinate slowly and unevenly because external structures impose a physical barrier. This study evaluated seed scarification and biomolecule-rich extracts from Trichoderma orientale and Pereskia aculeata Mill. as strategies to improve germination and early seedling development of U. brizantha cv. MG-5. The experiment used a 5 × 2 factorial design comprising five seed treatments and two seed conditions (scarified and non-scarified). Fungal extracts were produced by solid-state fermentation of T. orientale on orange peel or maize cob, whereas the plant extract was obtained from P. aculeata leaves. Proteolytic properties of the extracts and seed germination, seedling growth, and biomass accumulation were evaluated. The orange-peel extract had the highest proteolytic activity (200 U mL⁻¹). The orange-peel and maize-cob extracts exhibited similarly high specific proteolytic activities, whereas the P. aculeata extract showed the highest protein concentration (0.502 mg mL⁻¹). Scarification increased final germination from 50% to 69%, a gain of 19% points, and improved total seedling length and biomass accumulation. All seed treatments increased germination speed, first germination count, and final germination relative to the water control. The P. aculeata extract also promoted greater shoot growth and biomass production. These findings indicate that removing external seed structures effectively reduces the physical constraint on germination and that biomolecule-rich extracts can further support early seedling development. Seed scarification and bioactive extracts therefore represent promising complementary strategies for improving the physiological performance of U. brizantha seeds.