This study was undertaken to measure the impact of fertilizers (nitrogen-potassium) on the growth and the development of plantain banana. Different doses of fertilizers (T2, T3, T4, T5 and T6) were applied to two hybrid varieties (PITA 3 and FHIA 21) and a traditional variety (CORNE 1) on an experimental split plot plan with a planting density of 2500 plants per hectare. Results showed that fertilizers improve parameters of plantain than control (T1). T6 with high potassium content (240 kg•ha −1 N and 987 kg•ha −1 K) improved the growth (35.72 ± 0.95 cm•month −1 ) and the widening (9.56 ± 0.17 cm•month −1 ) of PITA 3, and performed FHIA 21 agronomic parameters by reducing the length of the production cycle and increased the length of fruits. T2 treatment improved FHIA 21 agronomic and yield parameters. Also, the weight of CORNE 1 regimens (9.00 ± 0.67 kg) and fruits (296.59 ± 4.50 g), the length (33.37 ± 0.31 cm) and the circumference (14.73 ± 0.31 cm) increased with T2. T4 induced shorter production cycle of PITA 3 (390.40 ± 0.67 cm•month −1 ), improved PITA3 regimens weight (10.33 ± 0.44 kg) and the number of hands by regimen (6.00 ± 0.00) of FHIA 21. T3 with weak nitrogen content (120 kg•ha −1 N and 658 kg•ha −1 K) improved the characteristics of PITA 3 fruits notably, the weight (176.09 ± 2.96 g) and the circumference (13.87 ± 0.89 cm). T5 (240 kg•ha −1 N and 329 kg•ha −1 K) performed CORNE 1 trees number of sheets (3.85 ± 0.16). CORNE 1 cycle production with T6 treatment was 137.80 days longer than those of T2 treatment (483 ± 3.50 days). In conclusion, with T2 and T6, growth parameters were globally improved in FHIA 21 by the regimen largest and the higher number of fingers, and productivity parameters were improved in CORNE 1 by the heaviest, the longest and the thickest of the fruits.