Influence of shade on the biomass and essential oil production of Lippia citriodora (Lam.), Brazil

Abstract

This study aimed to evaluate the effect of shading on the production of essential oil and biomass in Lippia citriodora (Lam.) – known as cidrão – in the north of Minas Gerais, Brazil. The experimental design was completely randomized, with four treatments and five repetitions. The treatments consisted of four levels of photosynthetically-active radiation (PAR) using “Sombrite” black shade netting of 25, 50, 70% of light and full sunlight as the control. The variables root dryness, shoot dryness, number of flowers, total dry weight, root/shoot ratio, and production and content of essential oil were analyzed. Statistically significant differences were observed for the root and shoot dry masses and total dry mass, number of flowers, total dry weight, root/shoot ratio, oil production and trichome number, but not for the oil content. The results showed that at full sunlight the biomass production and trichome number of cidrão were altered, but that the content of essential oil was unaffected.

Keywords

• medicinal plants
• plasticity
• radiation