Effects of conventional, organic and agroforestry management on leaf biomass, flavonoids and antioxidant activity of Passiflora edulis Sims

Abstract

The quality and leaf yield of Passiflora edulis Sims depend on agricultural management decisions that modulate growth, metabolite accumulation, and antioxidant responses. We compared three commercial agroecosystems in Paty do Alferes, Rio de Janeiro (conventional, organic, and agroforestry), quantifying vegetative growth, leaf biomass, secondary metabolites (total flavonoids and total phenolics), and functional markers (ABTS, DPPH, FRAP). A two-factor analysis of variance was applied to assess agroecosystem and temporal effects. Conventional cultivation exhibited the highest vegetative growth and biomass at 20 weeks after planting (1053.3 g fresh mass/plant; 207.8 g dry mass/plant). In contrast, the agroforestry system showed the highest mean flavonoid content (40.3 ± 4.3 mg RE g-1), followed by the organic (33.3 ± 3.01 mg RE g-1) and conventional systems (19.7 ± 2.51 mg RE g-1). Antioxidant activity varied across markers: FRAP values were greatest in the conventional (392.27 ± 33.84 µmol Trolox g-1), intermediate in the organic (357.79 ± 33.07 µmol Trolox g-1), and lowest in the agroforestry system (286.67 ± 15.79 µmol Trolox g-1). ABTS activity was numerically highest under conventional management (116.50, 91.81, and 88.71 µmol Trolox g-1 for conventional, organic, and agroforestry, respectively), and DPPH and total phenolics did not differ significantly among systems overall. These results indicate contrasting production profiles: conventional management favored leaf biomass and FRAP activity, whereas agroforestry favored flavonoid concentration per unit extract; the mechanisms underlying this inverse association were not experimentally resolved.