High-yielding and quality banana production through plant growth-promoting rhizobacterial (PGPR) inoculation

Abstract

Introduction. Rhizobacterial inoculation in low fertilizer-N conditions, viz., 33% fer- tilizer-N of the total N requirement, could produce similar plant growth to the 100% N-fertilization of banana plantlets grown under hydroponic conditions. Thus, we tested PGPR inoculation in com- bination with fertilizer-N application to study the role played by strains of rhizobacteria in nutrient accumulation, nitrogen fixation and, consequently, improvement in yield and fruit quality of bana- nas. Materials and methods. Two PGPR strains were used in the experiments, namely, Sp 7 (Azos- pirillum brasilense) and UPMB 10 (Bacillus sphaericus). The design of the experiment was completely randomized with three replications. Eight treatments were applied: control without fer- tilizer-N application (N0%) and without PGPR; N0% + Sp 7 ; N0% + UPMB10; N33% without PGPR; N33% + Sp 7 ; N33% + UPMB10; N100% without PGPR and N100% + UPMB10. One tissue-cultured banana (cv. 'Berangan') plantlet was planted in a plastic pot (4 L) for 45 days and thereafter trans- ferred to a larger polyethylene tank (1000 L) until maturity. A 100-mL broth culture of Sp7 or UPMB10 was added to the respective tanks after the transplanting process and repeat inoculations were per- formed monthly. The fruits were harvested at the maturity stage after 80-90 days of flowering. After ripening, yield and fruit quality parameters were assessed. Results. Inoculation with 33% fertilizer- N increased the total nutrient accumulation (N, P, K, Ca and Mg). PGPR inoculation along with 33% fertilizer-N significantly increased the bunch yield and fruit physical attributes, namely, finger wei- ght, length and diameter, and (pulp / peel) ratio, besides inducing early flowering by 3 weeks. Con- clusion. The results suggested that PGPR strains Sp 7 and UPMB 10 could be used as bioenhancer and biofertilizer for early, high-yielding and improved banana fruit production in 33% fertilizer- N conditions. Malaysia / Musa / plant nutrition / bacteria / nitrogen fertilizers / growth / yields / fruit quality Production de bananes de qualite, avec de forts rendements, par inoculation avec des rhizobacteries favorisant la croissance des plants (PGPR).