Enhancement of soil suppressive potential to bacterial wilt disease caused by <i>Ralstonia solanacearum</i>

The effect of wheat and maize rotations and the application of plant-animal compost on potato bacterial wilt and yield was investigated. The proposed method was tested in three separate locations, each two acres in size, with an untreated control. The first two were naturally infested, but the third was pathogen-free. Infested locations that had been treated experienced a significant reduction in disease incidence. The addition of a bio-fertilizer mixture (<i>Azotobacter</i> sp., <i>Azospirillum</i> sp., <i>Bacillus megaterium,</i> and <i>Bacillus circulans</i>) improved the compost’s suppressive potential. The method increased soil organic matter (SOM), N, P, K, Ca⁺², and Mg⁺² while decreasing Na⁺ levels and increasing potato yield. The relative abundance of <i>Ralstonia</i> decreased while that of <i>Arthrobacter</i>, <i>Streptomyces</i>, and <i>Nocardioides</i> increased. The presence of <i>Gracilibacillus</i>, <i>Cellvibrio</i>, <i>Bacillus</i>, and <i>Paenibacillus</i> was associated with a decrease in <i>Ralstonia</i>, whereas the presence of <i>Propionibacterium</i> (a nitrogen-fixing bacteria) was associated with an increase in <i>Ralstonia</i>.