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Taro response to different iron levels in hydroponic solution

Ares, A., Hwang, S.G., Miyasaka, S.C.
Journal of plant nutrition 1996 v.19 no.2 pp. 281-292
Colocasia esculenta, iron, nutrient availability, chlorosis, leaves, roots, biomass, leaf area, mineral content, nutrient content, nutrient-nutrient interactions, hydroponics, nutrient solutions, dry matter accumulation, nutrient deficiencies
Iron (Fe) deficiency is a nutritional problem limiting crop production worldwide. To determine the response of taro [Colocasia esculenta (L.) Schott cv. Bun Long] to Fe deficiency, taro propagules were grown for 35 days in hydroponic solutions with six initial levels of Fe (0, 1.25, 2.5, 5, 10, and 20 micromoles). Taro plants grown in the 0 micromole Fe level solution exhibited severe chlorosis of the leaf blades and abnormal root morphology characterized by reduced lateral root formation. Dry weights of leaf blades, roots, and petioles, total biomass, and leaf area were significantly lower in the 0 micromole Fe treatment than in the other treatments. However, there were no significant differences in these parameters among treatments in the range of 1.25 to 20 micromolar Fe. Segmented regression models best described both the effect of initial Fe levels on leaf blade Fe content (R2=0.98), and the relationship between leaf blade dry weight and leaf blade Fe content (R2=0.92). The critical Fe level in leaf blades is probably not a fixed point but rather a range between 55 to 70 mg Fe/kg (dry weight basis). No significant interactions were observed between Fe concentrations in the leaf blades and other nutrients.