Influence of Biomas and Soil Fertility on Caffeine Content of Guayusa (Ilex guayusa).

Influence of Biomas and Soil Fertility on Caffeine Content of Guayusa (Ilex guayusa) P. Crespo1, L. Cobos1, M. Rocha1, S. Balarezo2, P. Marañón3, G. García1* Leaves of guayusa (Ilex guayusa) have been consumed ancestrally by native people of Ecuadorian Amazon. Its consumption has been increasing because of its stimulating and curative properties associated with bioactive metabolites (MB), such as caffeine. The MB content is influenced by climate, soil, etc., however in the case of guayusa information about these factors is lacking. The objective of this study was to determine the influence of biomass, soil fertility on caffeine content (CC). The study was done in a plantation located to the northwest of the Ecuadorian Amazon; Province of Napo, Archidona County. One hundred forty four individuals were randomly selected from a field that was stratified by slope in high stratum (HS), medium stratum (MS) and low stratum (LS). A complete random design (CRD) was used. The variables evaluated were Organic Matter (OM), Leaf Area Index (LAI), and Normalized Differential Vegetation Index (NDVI). Analysis of variance (ANOVA) identified significant differences for the variables studied. The HS showed the highest OM content of 27.69% while the lowest 21.28 % was for the LS. The highest mean for CC of 2.75 mg 100 mg-1 was presented by the MS, which also presented the highest LAI of 12.89 m2 and 0.86 for NDVI, in contrast the lowest mean of 2.22 mg 100 mg-1 for CC, 5.99 m2 of IAF,0.82 NDVI were observed in the HS. There was correlation of 0.50 and 0.35 between CC and NDVI LAI, respectively. Key words: Caffeine content, biomass, soil fertility, guayusa. 1 Universidad Central del Ecuador. Facultad de Ciencias Agrícolas. *Corresponding autor gmgarcia@uce.edu.ec 2 Laboratorios Quimicas Ariston 3 Huasquilla Lodge