Effect of Organic Fertilizer Doses on the Plant Growth, Essential Oil Production and Chemical Substances of “Carqueja” over Two Harvest Moments

Abstract

Abstract:This study aimed to investigate, for the first time, the plant growth, essential oil content and their chemical substances of Baccharis trimera (Less.) DC., the first Brazilian variety of medicinal plant, in response to five doses of organic fertilizer (0,10,20,30,40 and 50 ton/ha) over two harvest moments-120 d and 242 d after transplanting (DAT). The work was carried out from February to October 2011 at the experimental farm of the Sao Paulo State University "Julio de Mesquita Filho" (UNESP), Brazil. The seedlings of B. trimera var. CPQBA-1 were respectively transplanted into experiment plots under six treatments: 0, 10, 20, 30, 40 and 50 ton/ha of organic fertilizer. Each treatment had four replications and each plot consisted of 12 plants. Then they were harvested at 120 DAT and 242 DAT, and the essential oil were extracted by hydrodistillation and analyzed by gas chromatograph. The results were subjected to analysis of variance and the means were analysed using Tukey's test (5%) followed by a regression analysis. The fertilizer dose significantly influenced the height of the plants in the second harvest, while the higher dose of organic fertilizer positively impacted the essential oil content in the first harvest. Also, the level of organic fertilizer was directly correlated with the production of dry matter during the regrowth. Twenty-seven substances were identified in the essential oil samples, and the major components were: bicyclogermacrene, trans-caryophyllene, germacrene-D, spathulenol and caryophyllene oxide. These findings suggest that to obtain higher yields of dry matter of B. trimera, it should be harvested around 242 DAT and organic fertilizer should be applied approximately to 50 ton/ha. Furthermore, higher doses of organic fertilizer and harvest at 120 DAT is able to increase the essential oil content.