Influence of Fertilizers on the Production of Plantains with Irrigation

Abstract

The fertilizer requirements of plantains (Musa acuminata x M. balbisiana, AAB) were determined for a San Antón sandy clay (Cumulic Haplustolls), with irrigation, on the southern coast of Puerto Rico. Significant responses per plant in number of fruit and weight per bunch were obtained with 168 kg N/ha. The use of the Capó fertilizer-yield equation indicated that applications of 259 and 282 kg N/ha would be required for a maximum yield of 155,988 fruit/ha weighing 45,030 kg. Levels of N in excess of 336 kg N/ha reduced production by restricting the number and weight of bunches/ha, with 673 kg N/ha having 22.8% less bunches than with optimum N fertilizer application. Leaf-N value of 3.20% at 10 mo of age was associated with response toN fertilizers and values of 3.66% with maximum production. Optimum K₂O fertilization rates, required for maximum yields, were 420 and 405 kg/ha for number and weight of plantains, respectively, with 336 kg K₂O giving 99% of maximum yields. Phosphorus increments up to 336 kg P₂O₅/ha
 failed to increase production per plant or per hectare. The unfertilized soil contained 45 p/m P (Olsen), and leaf samples from these plots contained 0.28% P in the leaf at 10 mo. Applications of 94 kg MgO/ha were sufficient to attain 95% of maximum yield potential for number and weight of fruit per ha. Soil and leaf values (699 p/m Mg and leaf 0.48% Mg) for the no-Mg treatment exceeded published critical values for plantains. For optimum production of plantains on an irrigated San Antón sandy clay, the use of 168 kg N and 336 kg K₂O/ha are suggested.