摘要：ABSTRACT: The present study involves phytochemical investigation, phenol content and allelopathic potential of Croton heliotropiifolius Kunth extract in the germination of Digitaria insularis (L.) Fedde. with extracts ethanolic and aqueous of C. heliotropiifolius leaf; was performed prospected secondary metabolites and Ultraviolet–visible (UV–visible) spectrophotometry tests for total phenols and flavonoids. The germination bioassay was performed in a BOD chamber (12L:12D) with plant extracts at 100, 50, 25 and 10%, with water as control against D. insularis seeds. The germination percentage (G%), germination speed index (IVG), abnormal seedlings (PAn%), root length and aerial part (CR and CPA) were evaluated. The extracts reduced the germination and development of the target species indicated by G% and IVG from the concentration of 10%. The same occurred with the variables PAn%, CR and CPA. In both extracts the presence of secondary metabolites was indicated, the phenol content obtained was 0.3422 mg EAG/g for the ethanolic extract and 0.375 mg EAG/g for the aqueous extract, for the flavonoids 0.1071 mg EQ/g in ethanolic extract and 0.0110 mg EQ/g in aqueous extract. The extracts demonstrated a reduction in germination and alteration in the physiology of Digitaria insularis (L.) Fedde seeds. KEYWORDS: Extracts, Secondary Metabolites, Germination.
