Produção de biomassa, teor de cumarina e análise foliar de plantas de guaco (Mikania glomerata Sprengel) cultivadas sob diferentes fontes de adubação e luminosidade

Abstract

The main objective of this work was to evaluate the effect of fertilization and luminosity on biomass production, coumarin content and anatomy of the leaves of Mikania glomerata, popularly known as guaco. The plants were cultivated under four sources of fertilizing (control, chemical fertilizer, cattle manure and poultry litter), in addition to the luminous conditions (full sun and under dark 50%). The variables were established by fresh matter of leaves (MFF), fresh stem matter (MFC), dry matter of leaves (MSF) and stem dry matter (MSC). In the evaluation of the MFF, it was observed that the plants cultivated under shading had higher biomass accumulation than those cultivated in full sunlight, independently of the source and fertilization used. The MSF analysis indicated that plants cultivated in soil with chemical fertilizer and under shading presented a better yield. Plants cultivated in soil with poultry litter also had an increase nthe CONTENT of MSF. The statistical analysis of the data of fresh and dry mass of the stem was not significant. To analyze the content of coumarin, 120 days after planting (DAP) the leaves were collected and taken for extraction and analysis of the contents of coumarin. After obtaining the results, the dosage of coumarin was performed by high performance liquid chromatography (HPLC). The data were submitted to ANOVA and compared with the appropriate tests for each variable studied. All plants cultivated under some fertilization had a higher concentration of coumarin in relation to the control. As for the luminosity, the plants cultivated in the sun had a lower coumarin content than that found in plants cultivated under dark 50%. Regarding the anatomy and the stomata count, the different treatments applied did not exert effect on the analyzed variables, however it was possible to observe a tendency towards a larger leaf area in the plants that remained in the shade. The results obtained will assist the producers in the proper management of the guaco, guaranteeing a standardization of the raw material and adding value to the production.