The aim of this study was to assess the influence of organic fertilization in 6 growth periods on β-ecdysone production by Pfaffia glomerata plants. The field work was conducted in "Santo Antonio do Araquá" Farm, Catâneo Ângelo District, São Manuel, São Paulo State, Brazil. The adopted design was in randomized blocks, in a 5x6 factorial arrangement, with four replicates and 8 useful plants per plot. Blocks were constituted of 6 growth periods (60, 120, 180, 240, 300 and 360 days after germination), and 5 chicken manure levels [control (without fertilization), 15, 30, 45 and 60 t ha-1]. After each harvest, roots were dried in forced aeration oven at 40ºC and weighed for later β-ecdysone extraction following the methodology developed by Magalhães (2000). Results were subjected to analysis of variance and mean separation by Scott-Knott test, both at 5% probability. When interaction was detected, results were evaluated using polynomial regression analysis. β-ecdysone content was not influenced by manure levels or plant growth periods. However, β-ecdysone total content per root was influenced by the growth period, and at 360 days after emergence there was a higher quantity of the active principle in all treatments. Although not statistically different from the remaining treatments, 30 t ha-1 led to the highest β-ecdysone production at 360 days after plant emergence.
Pfaffia glomerata; organic fertilization; β-ecdysone; medicinal plants
