Survival of phytopathogenic bacteria during waste composting

The survival of phytopathogenic bacteria, Erwinia carotovora subsp. carotovora, Xanthomonas campestris pv. vesicatoria, and Pseudomonas syringae pv. syringae was investigated during a horticultural waste composting process to determine to what extent they were eliminated during the process. The relative influence of temperature, antagonistic compost microorganisms, and phenolic compounds was assessed and compared. Results showed that all phytopathogenic bacteria disappeared in less than 60 h of composting, these bacteria showing low resistance to high temperatures (50, 60 and 70 degreesC). The highest survival was 1 h at 60 degreesC for P.s. syringae and 15 min at 70 degreesC for E c. carotovora. None survived > 15 h at 50 degreesC. Some culture filtrates of other compost microorganisms and some phenolic compounds also had an inhibitory effect which differed according to the phytopathogenic bacterial species. Composting is therefore considered a useful method for recycling horticulture wastes and eliminating phytopathogenic bacteria. (C) 2002 Elsevier Science B.V. All rights reserved.