Nitrogen Fertilization Effects on Boron and Chloride Concentration, Yield and Quality in Potato

Nitrogen (N) availability affects the boron (B) and chloride (Cl) concentrations in potato plants. The objective of our study was to evaluate: 1) the effect of nitrogen (N) fertilization on boron (B) and chloride (Cl) concentration in leaves and tubers, yield and tuber quality; and 2) the use of nitrogen nutrition index in shoot biomass (NNIsh) and in the tuber at harvest (NNItH) to estimate B and Cl nutrition status. Two trials were carried out (2009/10 and 2010/11). At each year, a split-plot randomized complete blotuber B uptakeck design with three replications was used. The main plot was the N rate applied at planting (0 or 50 kg N ha-1), and the subplots were the N rate applied at tuber initiation (0, 50 or 100 kg N ha-1). Our results showed that leaf B concentration and yield increased with N availability (13% and 5%, respectively). While leaf and tuber Cl concentration and DM decreased with N availability (16%, 18% and 3%, respectively). Moreover, the NNIsh was related to the leaf B and Cl concentration and relative yield. The NNItH was also closely related to dry matter (DM), B and Cl concentrations in tubers at harvest. This study demonstrated that N fertilization affected the concentration of B and Cl in leaf and tuber and that NNIsh and NNItH estimated the nutritional status of anionic micronutrients. Therefore, simultaneous N, B and Cl management is critical for increasing their use efficiencies and improving crop productivity.