ZINC, MANGANESE AND PHOSPHORUS INTERRELATIONSHIPS AND THEIR EFFECTS ON IRON AND COPPER IN CHELATOR-BUFFERED SOLUTION GROWN RUSSET BURBANK POTATO

Three hydroponic experiments were conducted with Russet Burbank potato to elucidate zinc (Zn) and manganese (Mn) relationships and associated interactions with other nutrients at different levels of phosphorus (P). Except when P was optimal, root Mn concentration was reduced at optimal solution Zn relative to deficient or excessive Zn levels. Shoot Mn generally increased with augmented solution Zn. As solution Zn increased, root P declined while shoot P and copper (Cu) and root iron (Fe) and Cu increased. Increasing solution Mn generally decreased Zn in all plant tissuesespecially in roots. The Mn influence on plant P, Cu, and Fe concentrations was nearly opposite the Zn impact, indicating that Zn and Mn have counter effects. Partitioning between root and shoot micronutrient concentrations occurred when available P was either deficient or excessive, which may also help explain poor plant health and adverse micronutrient relationships in potato when available P is not optimally maintained.