Comparative studies of iron inefficient plant species with plant analysis

Abstract

In pot experiments, a calcareous cnernozem was used to compare the susceptibility of corn (Zea mays L,), soybean (Glycine max Men’.), and peanuts (Arachis hypogaea L. ] to Fe deficiency. The objective of the study was to explain plant differences to susceptibility based on plant analysis. These plants showed visual symptoms of Fe deficiency chlorosis in the no Fe treatments. The rapidity and the severity of symptom development followed: peanut > soybean > corn. With each of the plant species, the symptoms of Fe chlorosis disappeared when Fe was applied, while ary matter yielas remainded unchanged.

Plant analysis showed a relationship between different plants for susceptibility to Fe deficiency ana Fe²⁺ concentration (Fe²⁺ expressed as a Fe²⁺ / total Fe ratio). and Ca/Fe²⁺ and Mn/Fe²⁺ ratios. Unlike the Ca/Fe²⁺ ratio, the Mn/Fe²⁺ ratio was of the same order of magnitude in each of the three species. It was above 1.0 in chlorotic plants and increased with plant susceptibility to Fe deficiency. This ratio could be used as a common diagnostic criterion to separate plants for response to Fe deficiency. No differences were found between chlorotic and healthy plants for total Fe or for K/Ca, P+K/Fe, and Zn/Fe ratios.

Key words:

• Iron
• chlorosis
• Calcareous soil
• Zea mays
• Glycine max
• Arachis hypogaea
• Bivalent iron
• Nutrient ratios