Effectiveness of endo-rhizobacteria as growth promoters and biological control of moler disease in shallots (Allium ascalonicum L.)

Abstract

The study aims to evaluate the effectiveness of endo-rhizobacteria in spurring plant growth and controlling disease in local Wakatobi shallots. The study was conducted at the Agrotechnology Laboratory of the Agronomy Unit, and Screen House of the Faculty of Agriculture, the University of Halu Oleo, from March to June 2019. The study used a completely randomized design with eight treatments, namely without endo-rhizobacteria (control ), Be03 (B) + W2R06 (R) isolates. ) (B + R), isolate SWRII B02 (S) + Bacillus sp. CKD061 (C) (S + C), S + R, B + R + C, B + S + C, S + R + C and B + S + R + C. Each treatment was repeated 3 times so that there were 24 experimental units. The variables observed were plant height, number of tillers, number of leaves, the incidence of moler disease, and salicylic acid production. Observational data were analyzed using analysis of variance, followed by Duncan’s multiple range test α 0.05 and regression analysis to see the relationship between salicylic acid production and the incidence of moler disease. The results showed that endo-rhizobacteria inoculation of Wakatobi local onion seeds was able to increase plant growth and was able to control disease in local Wakatobi shallots. Endo-rhizobacterial combination treatment of SWRII B02 + Bacillus sp. CKD061 (S + C) was able to increase plant height by 30.42%, number of tillers 72.03%, number of leaves 88.03%, salicylic acid production 24.36%, and reduce the incidence of moler disease by up to 100% when compared to controls. Seed treatment with a combination of endo- rhizobacteria isolates from SWRII B02 + Bacillus sp. CKD061 can be recommended as a growth booster and biological control of cancer in onions.