Yield, Uptake, and Retranslocation of Nutrients in Banana Plants Cultivated in Upland Soil of Central Amazonian

ABSTRACT

Banana cultivation is considered one of the most important agricultural activities of economic and social importance in Brazil. The objective of this work was to investigate the uptake, retranslocation and the effect of fertilization on the yield and uniformity of banana bunches (Musa spp.) cultivated in Central Amazonian, region with approximately 1.5 million km² or 150 million hectares. Two experiments were conducted in a Xanthic Ferralsol (dystrophic Yellow Latosol), the predominant soil of the region, examining: i) the nutrient uptake and translocation rate in twelve plants; and ii) the efficiency of zinc use, in a completely randomized blocks in a 4×2 factorial scheme in split plot design with four zinc sulfate (ZnSO₄) rates (0, 30, 60, and 120 g plant⁻¹ cycle⁻¹) and two application times (in the hole together with the seedling or as surface broadcast in the fifth month after planting), with four replicates. Uptake of macronutrients was in the order of potassium (K) > nitrogen (N) > calcium (Ca) > magnesium (Mg) > phosphorus (P) and micronutrients in the order of manganese (Mn) > iron (Fe) > boron (B) > zinc (Zn) > copper (Cu). The N, P, K, Mg, and Cu have a high retranslocation rate compared to other nutrients investigated. The bunch yield increased significantly in a quadratic fashion with increasing Zn rate and hole application method of zinc was more efficient compared to broadcast application. At high concentration, Zn presents a low mobility in the phloem from the leaves to the fruits. The critical leaf concentration of zinc at the start of inflorescence was 12.9 mg kg⁻¹.

Keywords:

• Musa spp.
• plant nutrients
• mobility nutrients
• critical zinc concentration

ACKNOWLEDGMENTS

We thank Western Amazonian Center of EMBRAPA (CPAA, Manaus—AM) and Produquímica Company for the financial support to conduct field experiments and to provide laboratory facilities for soil and plant analysis.

Notes

¹NF₁ and NF₃—foliar nutrients concentration at the beginning of inflorescence; NF₂ and NF₄—foliar nutrients concentration at the bunches yield; Δ—increment of foliar level-macronutrients = (NF₂-NF₁)/100 or micronutrients = (NF₄-NF₃)/100; FNR—fraction of nutrient retranslocated.