Phophorus and Zinc Relationships in Chelator-Buffer Grown Russet Burbank Potato.

Potato production requires high P availability with potential negative environmental and nutrient uptake effects. Impacts of high available P on potato and species in potato cropping rotations are inadequately understood, but antagonistic interactions with cationic micronutrients, such as Zn and Mn could result. Two experiments were conducted with Russet Burbank potato to elucidate P and Mn relationships and associated interactions with Zn. In the first, solution concentration was constant at 128 µM P while Mn concentration varied: 0.05, 3.2, 9.5, 28.5, 85.5, 256.5, and 769.5 µM Mn. In the second, plants were grown in every combination of three levels of P and Mn with Mn at 0.05, 9.5 and 769.5 µM and with P at 32, 128 and 1024 µM. Yield maximized between 9.5 to 85.5 µM Mn and declined at deficient (0.05 and 3.2 µM) and excessive (256.5 and 769.5 µM) solution Mn levels. Plant appearance reflected observed Mn-influenced yields. In both experiments, Mn increased in all plant parts with increasing solution Mn regardless of solution P. Also in both experiments, P concentration declined in all plant parts at sufficient Mn as compared to P changes under deficient or excessive solution Mn. In the variable Mn experiment, Zn concentrations consistently increased in new shoots with increasing solution Mn, old shoot Zn concentrations remained flat from 0.05 to 9.5 µM Mn levels but increased significantly above 9.5 µM Mn, and root Zn was not affected. In the double variable experiment, as solution P increased, root Zn increased as concomitant new and old shoot Zn decreases narrowed by increasing Mn levels. Available Mn was observed to control plant P levels and to influence Zn uptake and translocation, indicating that Mn has considerable impact on P, Zn and P-Zn interactions in potato, confirming previous findings of variable P and Zn studies.