Application effect of rhizobacteria Bacillus strain on plant growth and pest insects in shallot plantation (Allium ascalonicum L.)

Abstract

Rhizobacteria can enhance plant growth, yield, and resistance to pests. This study aimed to determine the effect of rhizobacteria Bacillus strain application on shallot plant growth and its effect on insect pests in the field. The research, conducted from September 2022 to January 2023, took place at the Microbiology Laboratory, Faculty of Agriculture, Universitas Andalas, and on the farm in Nagari Sungai Nanam, District of Lembah Gumanti, Solok Regency, West Sumatra. The research utilized a randomized group design with 12 treatments and three replicates. The treatments comprised ten rhizobacteria Bacillus strains, insecticide treatment (Siantraniliprol 20 g/L), and control (without Bacillus spp. and insecticide treatment). The results showed that shallot treated with Bacillus strain can increase plant growth. B. subtilis strain MRPLE3.1 enhanced plant height, B. welhenstephaenensis strain MRRDE3.4 increased leaf count, and B. cereus strain MRSNE5.1 effectively suppressed pest insect populations. Moreover, B. mycoides strain MRRZLL2.2 demonstrated the highest shallot production, particularly in dry weight. Overall, this research shows the promising potential of the rhizobacteria Bacillus spp. in increasing shallot yields and pest management. This research also offers a natural and sustainable approach to improving agricultural practices, especially shallot cultivation.