Interaction between bacterial biocontrol-agents and strains of Xanthomonas axonopodis pv. phaseoli effects on biocontrol efficacy of common blight in beans

Abstract

The bacterial biocontrol agents (BCAs) treatments were used for seed microbiolization; the bacterial biocontrol agents (BCAs) used selected from previous study on the control of Xanthomonasaxonopodis pv. phaseoli Xap) includes: Bacillus (DFs093, DFs348 and DFs769), Pseudomonas (DFs513, DFs831 and DFs842), Rhodococcus (DFs843 and DFs912), and the combinations C01 (DFs093+DFs769+DFs831), C02 (DFs093+DFs769+DFs842) and C03 (DFs093+DFs769+DFs348). Sixteen (16) Xap strains were collected from several Brazilian regions, and were inoculated in cotyledonary leaves. The symptom development was followed for 10 days. The treatments were compared by the area under the disease progress curve for disease incidence, severity, and index. In general, majority of the BCAs reduced, to some degree, the disease caused by different Xap strains. The combination C01, and the isolate DFs831 resulted in highest mean disease control. The data from this study suggest a relationship between the region of origin of Xap strain and the efficacy of BCA to control the disease caused by it. The use of combinations of these organisms increased the efficacy of the biocontrol of several strains of the same pathogen. A strain-BCA interaction was shown by data collected from this study, which evidence the importance of selecting a BCA or a combination of BCAs with a wider spectrum of action.

Foliar spraying with bacterial biocontrol agents for the control of common bacterial blight of bean

“…bras., Brasília, v.53, n.10, p.1101-1108, Oct. 2018 DOI: 10.1590/S0100-204X2018001000003 best treatments. In contrast to the results obtained in the present study, Corrêa (2017), working with 16 strains of Xap, concluded that the C01 combination resulted in maximum mean disease control. The authors found that the C01 combination and the DFs831 bacterium caused the greatest reductions in CBB incidence and severity for all strains, resulting, respectively, in 36 and 27% control.…”

Management of the Common Bacterial Blight of the Bean by Rhodotorula glutinis and Sporidiobolus johnsonii

“…Bacterial blight diffusion by the bacteria Xanthomonas axonopodis pv. phaseoli is one of the main limitations in the production of beans in regions of medium altitude and high temperatures and relative humidity (Corrêa et al, 2017). The pathogen can survive in the straw, on seed coat, in host plants and in soil, for a long period of time (Darrasse et al, 2018), however, a main day of spread is the seed.…”