Content of some chemical components in carrot (Daucus carota L.) roots depending on growth stimulators and stubble crops

Agronomic factors, and mineral fertilization in particular, have a strong impact on the quality of carrot roots. In recent years, researchers have begun to design eco-friendly agricultural practices that would stimulate the quality and yield of carrot roots. Our aim has been to analyse selected quality parameters pertaining to the chemical composition of carrot roots, and relate them to the application of different growth stimulators and cover crops. For this purpose, a field experiment was conducted in 2009-2011 investigating the effect of growth stimulators and stubble crops on the accumulation of chemical components in storage roots of carrot (cv. Laguna F1). The study included three growth stimulators: Asahi SL, Bio-algeen S 90 and Tytanit. Plots without any foliar application of these growth stimulators served as control treatment. Another factor consisted of the previous crop (spring barley) and stubble crops: tansy phacelia and a mixture of spring vetch and field pea, grown after the harvest of barley and then ploughed in. All the growth stimulators significantly reduced the NO3 content in carrot roots. Asahi SL significantly increased the phenolic content. The effects of the growth stimulators on the macronutrient content in carrot roots were statistically significant in the case of Mg and Na. Stubble cropping contributed to the reduction of nitrates and stimulated an increase in the content of phenolics as well as of P, K, Ca and Mg in carrot roots.