Magnesium Nutrition of White Rose Potato in Relation to Vegetative Growth and Minerals of Leaf and Root Tissues

Abstract

Abstract ‘White Rose’ potato plants (Solanum tuberosum L.) grown outdoors in water cultures with 0 to 16 meq/1 Mg displayed deficiency symptoms 30 days after transplanting ranging from severe to none. Corresponding growth reduction was caused by Mg stress. Critical concentrations in plant tissues for Mg deficiency were 0.06% Mg, dry wt basis, for the petiole and 0.09% for the blade of recently matured leaves. Magnesium stress lowered the Mg concentration of petioles and blades much more than that of the fibrous roots. It had no appreciable effect on K but it decreased Na in most plant parts. Magnesium stress increased Ca in the fibrous roots and petioles but decreased it in blades. It increased nitrate-N in all tissues, and increased PO4-P in the fibrous roots and petioles but decreased it in blades. All petioles, as a rule, were much higher in K, Na, NO3-N, and soluble PO4-P than the blades. Our results indicated that the minerals interacting with Mg depend on the plant part analyzed.