Variable Selectivity for Sr by Corn Hybrids Which Accumulate Different Concentrations of Sr, Ca, Mg, and K¹

Abstract

Four single‐cross corn hybrids (Zea mays L.) which differ with respect to their accumulations of Ca, Sr, Mg, and K were grown under greenhouse conditions in soil treated with 0, 100, 200, and 400 ppm of Sr as SrNO3. The investigation was conducted to determine if these hybrids would exhibit variable selectivity for Sr compared with Ca and Mg. All hybrids responded substantially to Sr additions to the soil. The concentrations of Sr in hybrids I and IV increased more with increasing rates of Sr than was observed for the other two hybrids. Relative to concentrations of Ca plus Mg in the plants, hybrid IV accumulated more Sr than did hybrid III with the other two hybrids being intermediate. Results for selectivity ratios indicated that Sr was removed as readily by hybrid IV as were Ca and Mg, while other hybrids were selective for Ca and Mg in preference to Sr. It was concluded that although variable selectivity was evident among the hybrids, the concentrations of Sr accumulated by the hybrids were predominantly a function of the availability of Sr in the soil and the Sr and Ca accumulation characteristics of the hybrids. It is not likely that hybrids can be developed which accumulate high concentrations of Ca and low concentrations of Sr.