USE OF A COLONIZATION-DEFICIENT STRAIN OF ESCHERICHIA-COLI IN STRAIN COMBINATIONS FOR ENHANCED BIOCONTROL OF CUCUMBER SEEDLING DISEASES

Seed treatments containing combinations of Escherichia coli S17R1 and Burkholderia cepacia Bc-B provided significantly greater (P less than or equal to 0.05) suppression of cucumber seedling pathogens in a fiel d soil naturally infested with Pythium and Fusarium spp. than seeds tr eated individually with strains Bc-B, S17R1, or Enterobacter cloacae 5 01R3. Although strain S17R1 had no effect on disease severity when app lied alone and did not colonize cucumber rhizosphere, it enhanced the biocontrol effectiveness of strain Bc-B.