Potassium as an intensifying factor for iron chlorosis

Abstract

This research was conducted to determine the interactive effect of different potassium (K) and iron (Fe) rates on the growth and nutrient uptake of maize. The work also investigated the effects of high amounts of K on Fe uptake and on the occurrence of Fe chlorosis. For this purpose, five K (1, 2, 4, 6 & 8 mM) and four Fe (30, 60, 90 & 120 mu M) doses were applied to maize (Zea Mays L. cv. BSC 6661) plants in a re-circulated hydroponic system. Increasing K and Fe levels had positive effects on the dry weight of the maize leaves and roots. Total Fe concentrations and their uptake increased with the increasing levels of Fe and K, but decreased with the highest K dose. This response was similar to dry weight and the SPAD values with increasing Fe. We conclude that adequate K may also be required for the efficient use of Fe. However too high a concentration of K will cause competition with Fe.