Phenological characterization of chipilin (Crotalaria longirostrata Hook. & Arn.) and relationship between the phenological stage and chemical composition of leaves

Chipilin (Crotalaria longirostrata) is a traditional quelite from Mexico that is consumed in various dishes and traditional stews; however, information on the nutritional quality of this plant during its phenological devel-opment, including variation in secondary metabolites, is lacking. This information is essential to determine the appropriate time for harvesting the foliar biomass of this plant. The objectives of this research were to characterize the phenology of chipilin using the Biologische Bundesanstalt, Bundessortenamt und Chemische Industrie (BBCH) and to evaluate the contents of proteins, minerals, polyphenols and total flavonoids in the foliar biomass of this plant during phenological development. The results allowed the identification of 9 pri-mary phenological stages of chipilin, from germination to pod maturation, using the Biologische Bundesan-stalt, Bundessortenamt und Chemische Industrie (BBCH). The phenological cycle is long (eight months to first flowering) and requires elongation and thickening of the main stem to initiate secondary branching and flowering. Once the main stem has thickened, the dominance of the apical meristem of the main stem is bro-ken, and branching begins, with vegetative parts, flowers and fruits developing at the same time. Fruiting and seed production depend on the number of branches since terminal inflorescences are produced. Subse-quently, there are successive cycles of flowering and fruiting. Throughout the phenological cycle, the stem presented the highest accumulation of biomass, followed by the leaves and roots. An increase in leaf area was observed from primary stage 3 to primary stage 6 (the beginning of flowering). Beginning in primary stage 6, leaf biomass also decreased. Primary stages 1 to 4 had the highest contents of leaf proteins (27.0-28.8%) and of macro-and micronutrients. The protein content was high during primary stage 0 and in seeds (40.7% and 43.9%, respectively). The total phenolic compounds and total flavonoids did not vary signifi-cantly during phenological stages 1 to 8 (27.5-41.8 mg g-1 DM (dry matter) and 20.8-35.3 mg g-1 DM, respectively). Primary phenological stage 0 (germination) and secondary stage 09 (formation of cotyledonous leaves) presented high contents of P and particularly high contents of Fe, Mn, Zn and Cu.(c) 2023 SAAB. Published by Elsevier B.V. All rights reserved.