EXPORTATION AND PHOSPHORUS USE EFFICIENCY IN ‘BARRAGANETE’ BANANA (Musa paradisiaca L.)

Abstract

Plantain (Musa paradisiaca L.) represents the main export product of Ecuador, especially in the province of Manabi; however, there is a phenomenon of deterioration of fertility and soil degradation, thus, there is a need to mitigate it through fertilization strategies. A study was carried out at the Río Suma experimental farm of Laic Eloy Alfaro University of Manabi, aimed to evaluate the efficiency of the fertilization dose and the fractionation of P on Barraganete plantain in a farm in Manabi, Ecuador. A high population density (2200 plant ha^-1) was used and a standard dose of 100 kg ha^-1 of N, 200 kg ha^-1 of K2O and 70 kg ha^-1 of MgO was applied. The factors under study were P fertilization with three levels (20, 40 and 60 kg ha^-1 of P₂O₅) and fractionation with two levels (100 and 40-60 % of P₂O₅), resulting in a 3 × 2 + 1 factorial arrangement of treatments, distributed under a randomized complete blocks experimental design with three replications; the experimental unit consisted of 21 plants, of which five were selected form the central part for the evaluations. The evaluated traits were agronomic efficiency (AE), partial productivity factor (PPF), partial nutrient balance (PNB), dry fruit biomass, yield, concentration and exportation of P₂O₅; the latter was higher with the dose of 40 kg ha^-1 and fractionation of 100 % (6.01 kg ha^-1); AE, PPF and PNB presented the highest values: 211.3, 1,002.5 and 0.21 k ha^-1, respectively with the dose of 20 kg ha^-1 and the fractionation 40-60 %. The fractionation 40-60 % with a dose of 20 kg ha^-1 produced the highest yield (20,050 kg ha^-1). The relationship between dose and fractionation was inversely proportional, while between yield and agronomic efficiency of P the relationship was quadratic. Thus, appropriate recommendations can be established for fertilizing the crop with P₂O₅.