Effect of mineral fertilizing (N-P-K) and seasonality in yeld and total flavonoids in male individuals of Baccharis trimera Less. (Asteraceae) - Carqueja

Abstract

An agronomic assay was conducted to evaluate biomass production and to spec!rophotometrically quantify flavonoids in male individuals of Baccharis trimera Less. (Carqueja) varying N, P and K nutrients. Experiments were conducted in 3 blocks of 8 treatments. Each strip of 3 double rows received 48 seedlings. The treatments involved 60 kg N/ha; 60 kg P/ha; 60 kg K/ha, 60 kg N + 60 kg P/ha, 60 kg N + 60 kg K/ha; 60 kg P + 60 kg K/ha; 60 kg N + 60 kg P + 60 kg K/ha and the control. Data were recorded 6 months after planting, 3 months after the first harvesting and 3 months after the second harvesting. Fresh and dry weights were evaluated and total flavonoids were quantified through spectrophotometric methods using AlCl₃ at 420 nm and rutin as standard, Obtained results did not differ statistically within different treatments and periods of harvest (Tukey test < 5%), however plants after 9 months of culture, harvested in the spring, showed increased fresh and dry weights while plants cultured for 1 year, harvested in lhe summer, displayed enhanced yields of flavonoids.