This study was carried out to evaluate interactions between magnesium and the micronutrients manganese, zinc, copper and iron, determining their concentrations in different parts of Phaseolus vulgaris L. cv "Carioca". Bean plants were grown in pots containing nutrient solutions with low ms levels (2.4 and 24.3 mg.L-1), standard (48.6 mg.L-1) and high levels (72.9 and 97.2 mg.L-1). The experimental design was a completely randomized factorial, with 5 magnesium levels and 5 samplings every 14 days, starting 25 days after sowing. Plants grown at Mg levels below 48.6 mg.L-1 had lower Mg concentration in roots, stem and leaves; lower Cu concentration in leaves; higher Zn concentration in leaves, and higher Mn concentrations in roots in comparison to the control. When magnesium level was 97.2 mg.L-1 plants had higher Mg concentration in leaves, suggesting its absorption and translocation from root to shoot. These plants also revealed lower Cu concentration in stem and fruits and lower Mn concentration in the roots. Mg and Mn concentration in roots varied always in opposite direction, suggesting an inverse relationship in the absorption of these elements. Changes in Mg levels in nutrient solution caused little effects in the concentration of micronutrients but can cause significant differences in the development of the common bean.
Phaseolus vulgaris; magnesium; micronutrients; nutrient interactions