| Application of soil amendments has been proposed as an excellent agronomic strategy to suppress bacterial wilt of tomato infected by Ralstonia solanacearum. To evaluate the effects of soil amendments on the disease incidence and provide optimized compounds formula, compounds of rock dust, yeast-produced residue, chitosan, and sodium alginate produced residue were applied to the soil separately or mixed at different ratios（85%∶15%, 90%∶10% and 95%∶5%） in the greenhouse experiment. Results indicated that treatments C（rock dust∶yeast-produced residue=9∶1） and F（chitosan） were the most effective formulas in suppressing the bacterial wilt with the control efficacies of 98.3% and 66.3%, respectively. Furthermore, the appearances of diseased symptoms of these two treatments were delayed by 19 d and 10 d, respectively. Comparing to CK, formula C and F also could significantly promote plant growth by increasing leaf area, plant height, and stem diameter. Within a certain soil acidity（pH 5.0~6.5）, disease severity had highly significant positive correlation with soil pH, however, there was a significant negative correlation between the time of wilt attack and soil pH. Biolog analyses suggested that formula C could not only improve soil microbial community structure but also increase the rate of substrate utilization of microbe and the microbial species richness. This enhanced the stability of soil microbial ecosystem and benefited soil pathogen suppression, thus obtained the effect of disease suppression. |
