Yacon development and production under different potassium fertilisation doses

Increased interest in yacon root consumption has led to the need of developing research on such a culture. Mineral nutrition is one of the important points to be investigated since information about this subject remains scarce for this species. Thus, understanding the role played by potassium in expanding yacon culture is of paramount importance, since this mineral plays key role in plants’ growth and development processes, mainly in plants accumulating reserves in underground organs due to their most varied functions in metabolite transport processes. Thus, the aim of the current study is to assess the development and yield of yacon roots subjected to different potassium fertilisation doses. The experiment has followed a completely randomized block design, with 4 repetitions and 5 treatments: 178.7 kg.ha-1, 357.4 kg.ha-1, 536.1 kg.ha-1 and 714.8 kg.ha-1 of potassium chloride (KCl), which corresponded to 50%, 100%, 150% and 200% of reference value; and one control (non-fertilized soil). Morphological, physiological, and productive features were assessed based on the applied doses. Results have shown that the application of 357.4 kg.ha-1 of KCl (100% dose) was the one presenting the best agronomic efficiency for yacon root culture. It was also the dose providing the greatest economic efficiency because it produced larger number of roots in the most valued classes available in the market