Effects of fertilisation on the initial growth and diversity of secondary metabolites in Genipa americana

Abstract

The tree species Genipa americana ('Jenipapo') is found in the Brazilian Cerrado. It is economically important for its wood and fruits, used in traditional medicine and in the recovery of degraded areas. Based on the multiple uses of this species, we aimed to analyse the effect of different fertilisers (including a control [without fertilisation]) and chemicals (NPK = nitrogen, phosphorus and potassium chloride), both organic (vermicompost) and mixed (NPK + vermicompost), on early field growth and secondary metabolite production in young and mature G. americana leaves for 12 months, with monthly collections. The growth analysis indicated that the species develops better in fertilised soils in terms of the height and diameter of the collar, in relation to the control, with the different types of fertilisation presenting equivalent results. Therefore, it is suggested that in the reforestation of degraded areas, such as the Brazilian Cerrado, fertilisation is necessary for ‘Jenipapo’ planting as an alternative to reduce the degradation levels in this region. The same pattern was found in the analysis of the metabolic classes and the frequency of the treatment compounds, with a predominance of phenolic and flavonoid compounds in young and mature leaves. Only a different pattern was found for NPK + vermicompost, with a greater intensity of tannins and cardiotonic heterosides. The use of leaves for medicinal purposes is advised because, depending on the fertilisation, there may be higher production of cardiotonic heterosides, which are considered toxic.