Isolates of Bacillus spp. to promote growth and protection of garlic (Allium sativum L.) cultivation

Garlic (Allium sativum L.) is among the most widely consumed vegetables in Brazil; however, a significant proportion of the national demand is met through imports. In recent years, domestic garlic production and productivity have improved due to the adoption of advanced agricultural technologies. Nevertheless, certain factors, such as soil-borne diseases caused by pathogenic fungi, continue to hinder further increases in yield. Root diseases such as white rot caused by Stromatinia cepivora Berk (sin =. Sclerotium cepivorum) is notably difficult to manage and can lead to substantial crop losses. In this context, biological control using rhizobacteria has emerged as a viable and efficient alternative. The present study conducted two greenhouse experiments to evaluate the ability of rhizobacteria isolated from soils of garlic-producing regions. In the first experiment, four isolates were used in a sterilized system, and in the second one, five isolates were inoculated in plants grown in soil. Therefore, the isolates EB01, EB15, EB17, and EB21 significantly promoted garlic growth. In the second experiment, the isolates EB01, EB13, EB18, EB19, and EB24 significantly reduced the incidence of S. cepivorum. They showed greater similarity, according to the 16S rRNA gene, to Bacillus velezensis, Bacillus rugosus, Bacillus subtilis, Bacillus tequilensis, and Bacillus velezensis, respectively.