The Effect of Plant Growth–Promoting Rhizobacteria on Several Growth Parameters of Three Sugarcane ( Saccharum officinarum L.) Varieties

Increasing national sugarcane production can be achieved using the bud‐set technique to obtain high‐quality seeds. The obstacle to the sugarcane bud‐set technique is its low germination rate. Efforts to overcome low germination capacity include using plant growth–promoting rhizobacteria (PGPR) as growth promoters. This study aimed to determine the effect of PGPR concentration on the growth of bud‐set seedlings of several sugarcane varieties and analyze some physical and chemical properties of the soil. This research method adopted a randomized group design factorial pattern with two factors and three replications. The PGPR was collected from bamboo roots and mixed with nutrients. The bud sets of three sugarcane varieties: CM 2012 (V1), Kidang Kencana (V2), and Bululawang (V3), were collected from Takalar Sugar Factory, Perkebunan Nusantara XIV State Company. The PGPR treatments consisted of T 0 = 0 mL L −1 (control), T 1 = 10 mL L −1 , T 2 = 20 mL L −1 , and T 3 = 30 mL L −1 . The PGPR treatment was applied by pouring sugarcane plant media, as per a predetermined treatment, in the morning, with three applications at 7, 15, and 30 DAP, at a volume of 250 mL/polybag. The parameters measured were plant height, leaf number, stem diameter, tiller number, root length, and root dry weight. The PGPR treatment had a significant effect on all parameters, whereas the sugarcane variety had no effect on differences in response, except for roots (length and dry weight). In the CM 2012 variety, PGPR at 30 mL L −1 consistently increased growth parameters, except for the number of tillers. In the Kidang Kencana variety, a concentration of 10 mL L −1 increased the number of leaves, root length, and root weight. In the Bululawang variety, PGPR at 20 mL L −1 increased plant height and stem diameter. PGPR has a positive effect on soil fertility by increasing the nutrient content of nitrogen (N), phosphorus (P), and potassium (K), as well as improving the cation exchange capacity (CEC) of the soil. Therefore, when growing sugarcane bud sets, it is recommended to apply PGPR with an appropriate concentration depending on the variety.