Comportamento fotossintético, anatômico e produtivo de Melissa officinalis L. cultivada sob malhas coloridas

Abstract

Studies related to the pursuit of a favorable environment for the production of medicinal plants with a focus on optimizing the synthesis of active substances are necessary in view of the economic and social importance of these species. This study aimed to evaluate the effect of quantitative and qualitative control of the spectrum of light transmitted through the shading nets on growth and essential oil production in plants of Melissa officinalis L. The experiment was conducted in Presidente Prudente / SP. Plants were potted and subjected to shading treatments offered by black net (retention of 50 %), Chromatinet ® red and blue shading nets (50 %) and full sun for a period of 120 days after transplanting (DAT) , in which two cuts were performed. It was determined the global solar radiation, the photosynthetic photon flux density, the chlorophyll content , the plants gas exchange, biometric and anatomical parameters and content and yield of essential oil in leaves . The experiment was performed in a completely randomized design with 4 treatments and 5 replications. Based on the results, it was found that despite melissa be considered as a plant with better development in shaded environments, this specie has adapted to the condition of full sun, in which the photosynthetic data were more significant , indicating no damage to the photosynthetic apparatus. However, the use of the blue net resulted in higher biomass production and essential oil content in plants, and therefore its utilization is indicated for Melissa production. No anatomical changes were observed as a result of the cultivation of Melissa under different quantity and quality of light.