“Azospirillum brasilense associado a tipos de adubação no desempenho agronômico, avaliação do óleo essencial e anatomia de folhas de Pelargonium graveolens L’HÉR”

Abstract

Geranium (Pelargonium graveolens L.) is an aromatic medicinal plant of the Geraniaceae family, widely exploited in the pharmaceutical, cosmetic and aromatherapy food industry due to the wide range of therapeutic activities provided by its chemical composition. Studies on the cultivation of geranium demonstrate that different biological and abiotic factors can influence the development of the crop. Thus, there is a need to develop a strategic management system that favors the development and production of secondary metabolites of commercial interest. Therefore, this study aimed to evaluate the effects of fertilizer sources on agronomic growth, essential oil content, yield and chemical composition, as well as the anatomical characteristics of the leaf and photosynthetic pigment content of the species subjected to fertilizer sources. Fertilization was represented by seven treatments: T1) soil + N-P-K; T2) soil without fertilization; T3) soil + biodynamic fertilization; T4) soil + organic fertilization; T5) soil + biodynamic fertilization + plant growth promoting bacteria (BPCP); T6) soil + organic fertilizer + BPCP; and T7) soil + compost. Plants submitted to treatments T1, T3 and T5 had lower agronomic growth rates, as well as scarce essential oil content and yield. The application of Azospirillum brasilense (BPCP) did not cause significant differences in the agronomic growth, content and essential oil yield of P. graveolens. Plants submitted to treatments T4 and T6, organic fertilization and organic fertilization + BPCP, respectively, were the ones that added the greatest agronomic growth, essential oil content and yield. Thus, it is inherent that an organic fertilization can be considered a promising production technology for the commercial cultivation of P. graveolens. Plants submitted to compost (T7) had greater thickness in the evaluated leaf anatomical characteristics. Higher levels of chlorophyll (a, b and total) and carotenoids were extracted from plants grown only in soil (T2) and in the biodynamic treatment (T3).