Boron Effect on Mineral Nutrients of Maize
- A. Mozafar
Boron deficiency affects the uptake of several elements by plants. Information on the effect of B on yield and nutrient uptake by maize (Zea mays L.) is limited. This sand-culture study was conducted to acquire information on the long-term effects of B and interruption of its supply on yield, and the concentrations of 12 elements in earleaf and root of two maize hybrids, Mutin and Carlos Semu 201 (CS 201). Hybrids differed significantly in the concentrations of 11 elements in the earleaves and eight elements in the roots. Increase in solution B concentration increased the concentration of B in the earleaf and root and changed the concentrations of N, P, Mn, Fe, Zn, and Mo in the earleaf and Ca, Mg, Mn, Fe, Zn, Cu, and Mo in the root. Interruption of B supply from tasseling to maturity significantly reduced ear and total yield, decreased B concentration, and altered the concentrations of several other elements in earleaf and root. Significant interactions between B concentration and interruption of B supply, and hybrids with yield and concentrations of several earleaf and root nutrients were observed. Earleaf concentrations of N, K, Ca, Mg, Na, Cu, Mn, and Mo in Mutin, and K, Ca, Cu, and Mo in CS 201 showed significant correlation with earleaf B. Root concentrations of Ca, Fe, and Na in Mutin and Ca, Fe, Mn, and Mo in CS 201 showed correlation with root B. These observations indicate that B, depending on its concentration in the rooting medium, the element under study, and the hybrid, may change the uptake and transport of several other elements in maize. This effect of B, presumed to be due to changes in the membrane transport properties, supports similar findings in other plants. The relationships between the concentrations of K, Ca, Cu, and Mo with the B in the earleaves of both maize hybrids, if proved to hold true under field conditions, indicate that in studies on the uptake of these elements by maize the availability of B in the growth substrate needs also to be taken into account. The confounding effect of B in the rooting medium on the concentration of other elements in the earleaves and in the roots, which could be different for the same element in different hybrids or for different elements in the same hybrid, may partly explain the inconsistency observed by different workers in the yield response of maize to B fertilization.
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