Effects of bicarbonate induced iron chlorosis on selected nutrient contents and nutrient ratios of shoots and roots of different maize varieties

Abstract

The effects of HCO3- on chlorosis, some macro and micro nutrient uptake of different maize cultivars and some nutrient element ratios were examined. For this purpose a greenhouse experiment was conducted with thirteen different maize varieties and grown on five different nutrient solutions containing 20 μM Fe-EDTA and HCO3- levels (7.5; 15 and 30 mM as NaHCO3). According to the HCO3- applications, all maize varieties gave response to iron chlorosis. Iron chlorosis was slightly developed in plants grown with S3 (7.5 mM NaHCO 3), but it became severe in S4 (15 mM NaHCO3), especially S5 (30 mM NaHCO3), and control plots of all maize varieties. Application of 20 μM Fe (Fe-EDTA) increased both shoots and roots dry weights of maize varieties in general. Sodium amounts of the plants both in shoots and roots increased with the increasing amounts of NaHCO3. Potassium, phosphorous, calcium and magnesium contents on shoots and roots, degreased by the application of both Fe-EDTA and NaHCO3. Zinc (Zn) contents were found to be highest in shoots and roots of maize grown with S2 (20 μ M Fe), but decreased with the increasing HCO3- amounts. Due to iron and increasing amounts of HCO3-, Manganese (Mn) contents of varieties degreased and found under sufficiency ranges. P/Fe and K/Ca ratios on shoots and on roots were found higher in chlorotic plants especially grown on control and HCO3- applied plots. In contrast, Fe/Mn ratio was found higher in 20 μM Fe-EDTA than chlorotic plants. © 2006 Asian Network for Scientific Information.