Biostimulant in acclimatization of micropropagated banana (<i>Musa</i> spp.) seedlings

Abstract

Microorganisms, such as growth-promoting bacteria, may favor the obtaining of better-quality banana (Musa spp.) seedlings. This study aimed to evaluate the effect of inoculation with growth-promoting bacteria Bacillus sp. on micropropagated seedlings of banana cv. ‘Prata Catarina’ in the acclimatization phase. The design was in randomized blocks, with 4 treatments (negative control: no inoculation and no fertilization; positive control: application of slow-release fertilizer; inoculation with Bacillus sp. strain 186; and inoculation with Bacillus sp. strain 109) and 4 replicates (14 experimental units), totaling 224 seedlings. The bacterial population in the rhizosphere was quantified and the growth of seedlings and contents of minerals were evaluated. Seedlings treated with slow-release fertilizer showed better performance for the number of leaves (6.14 ± 1.44), shoot (3.64 g ± 1.72) and root (4.76 g ± 3.23) fresh weight and root dry weight (0.72 g ± 0.43). Using strains alone did not promote the growth of seedlings, under the conditions of the present study. Nevertheless, the strains were efficient in increasing the nitrogen content in leaves (17.93 g kg^-1 ± 0.73, strain 109) and potassium and magnesium contents in roots (6.96 g kg^-1 ± 0.39 and 6.98 g kg^-1 ± 0.40, strain 186).