ABSTRACT
Pogostemon cablin (Blanco) Benth. is an aromatic species popularly known as patchouli. The essential oil rich in patchoulol extracted from leaves is used by the pharmaceutical industries. The objective was to investigate the effects of shade nets and shading intensities on P. cablin growth, anatomy, chemical composition and essential oil content. The experiment was conducted with two types of shade nets (black and Aluminet), three light intensities (30, 50, and 70% shading) and full sun. The different light intensities influenced the growth and the essential oil yield, and chemical composition. Patchouli plants grown in an environment with shading showed higher values for the leaf, stem, root ant total dry weights compared to full sun. At 50% of shading, Aluminet provided gain in stem and total dry weights. Aluminet and black net at 50 and 70% of shading enhance essential oil yield. Patchoulol and pogostol contents were higher under full sun, and, black net and Aluminet at 50% shading. The environment for patchouli cultivation can be improved by use shade nets, especially with Aluminet at 50% of shading.
Pogostemon cablin (Blanco) Benth. é uma espécie aromática popularmente conhecida como patchouli. O óleo essencial rico em patchoulol extraído de folhas é utilizado pelas indústrias farmacêuticas. O objetivo foi investigar os efeitos das malhas e intensidades de sombreamento no crescimento, anatomia, composição química e teor de óleo essencial de P. cablin. O experimento foi conduzido com dois tipos de malhas (preta e Aluminet), três intensidades de luz (30, 50 e 70% de sombreamento) e pleno sol. As diferentes intensidades de luz influenciaram o crescimento, o rendimento e a composição química do óleo essencial. Plantas de patchouli cultivadas em ambiente sombreado apresentaram maiores valores para os pesos secos de folha, caule, raiz e total em relação ao pleno sol. Com 50% de sombreamento, Aluminet proporcionou ganho de peso seco de caule e total. Aluminet e malha preta a 50 e 70% de sombreamento aumentam o rendimento do óleo essencial. Os teores de patchoulol e pogostol foram maiores a pleno sol, malha preta e Aluminet com 50% de sombreamento. O ambiente para o cultivo do patchouli pode ser melhorado com o uso de malhas de sombreamento, especialmente com Aluminet em 50% de sombreamento.
Subject(s)
Lighting/adverse effects , Oils, Volatile/chemistry , Pogostemon/anatomy & histology , Pogostemon/growth & developmentABSTRACT
The purpose of this investigation was to determine the influence of colored shade nets on the growth, anatomy and essential oil content, yield and chemical composition of Pogostemon cablin. The plants were cultivated under full sunlight, black, blue and red nets. The harvesting was performed 5 months after planting and it was followed by the analysis of plant growth parameters, leaf anatomy, essential oil content, yield and chemical composition. The plants grown under red net have produced more leaf, shoot, total dry weight and leaf area. Plants cultivated under colored nets showed differences in morphological features. Plants maintained under red net had a higher leaf blade thickness and polar and equatorial diameter of the stomata ratio. Additionally, higher yield of essential oil in the leaves was observed under red and blue colored shade net. The essential oil of the plants grown under red net showed the highest relative percentage of patchoulol (66.84%). Therefore, it is possible using colored shade nets to manipulate P. cablin growth, as well as its essential oil production with several chemical compositions. The analyses of principal components allowed observing that pogostol has negative correlation with α-guaiene and α-bulnesene. There was difference in total dry weight and patchoulol content when the patchouli is cultured under the red colored shade nets.