Nutrient status of the banana cultivar 'FHIA-01' as affected by boron excess

A greenhouse experiment was carried out to study the effects of high boron (B) on the concentrations of various mineral elements in leaves, pseudostem and root of the banana cultivar 'FHIA-01', a cold- and wind-tolerant cultivar producing higher quality fruits in sub-tropical than in tropical conditions. The experiment was performed under hydroponic conditions at the Agricultural University of Athens, Greece. The plants were grown in plastic pots containing an inert substrate consisting of sand and perlite (1:2, v/v). They were fertigated three times a week with a full strength Hoagland's nutrient solution containing either 25 (control) or 400 (B excess) μΜ B. Five plants (replicates) were used per each B treatment. Eighty three days after the beginning of B treatments, leaves, pseudostem and root of each experimental plant were separately collected, oven dried and milled to a fine powder. Afterwards, the concentrations of B, K, Ca, Mg, Fe, Mn, Zn, Cl and Na were determined using standard methods. Boron concentrations in all plant parts were significantly increased, as B concentration in the nutrient solution increased from 25 to 400 μM. Regardless of B treatment, significantly higher B concentrations were found in leaves than in pseudostem and root. Furthermore, significantly lower concentrations of K, Mn and Cl, and higher concentrations of Ca and Mg were found in the leaves of control plants than in those treated with 400 μΜ B. Concerning the nutrient status of pseudostem, B excess resulted in an increase of the concentrations of K, Mn, Cl and Na. Finally, the concentrations of all studied nutrients in plant roots were similar in both treatments (25 and 400 μM B), aside from B and Cl that were significantly increased under B excess conditions.