OPTIMIZING PHOSPHORUS AND ZINC CONCENTRATIONS IN HYDROPONIC CHELATOR-BUFFERED NUTRIENT SOLUTION FOR RUSSET BURBANK POTATO

High rates of phosphorus (P) fertilizer for potato production have potentially negative environmental and nutritional consequences, including antagonistic interactions with micronutrients. Variable P or zinc (Zn) treatments were evaluated in chelator-buffered solutions to identify deficient, sufficient, and excess concentrations for Russet Burbank potato. Visual observations, dry matter, and nutrient concentrations confirmed 0.1 and 2 mu M as deficient, 6 to 54 mu M as sufficient and 162 and 456 mu M Zn as excessive under variable Zn; and 32 mu M as deficient, 64 to 512 as sufficient and 1024 and 2048 mu M P as excessive under variable P. A strong impact of solution Zn on P concentration and almost no impact of solution P on Zn concentration of potato were observed. New and old shoot and root Mn concentrations were affected by solution P. Results facilitate further study of P-Zn interactions using the chelator-buffered solution.