Riduzione dei danni da gelo sul carciofo mediante il contenimento biologico e chimico dei batteri criogeni

Reduction of frost injury to artichoke by biological and chemical control of INA-bacteria. The results of biological and chemical control of INA (ice nucleation active) epiphytic bacteria and their effects on frost injury in artichokes "Spinoso sardo" in Sardinia (Italy) are reported. Two non-INA antagonistic Pseudomonas fluorescens strains (MG3 and 12PV), which were isolated from field-grown artichoke leaves, and some chemicals (streptomycin + tetracyclin, kasugamycin and cupric hydroxide) were tested. The bacteria on the artichoke leaves were both INA and non-INA P. fluorescens and P. syringae strains; three INA strains of P. syringae were also pathogenic to young artichoke plants. In vitro, the two non-INA P. fluorescens strains showed an antagonistic activity against two INA P. fluorescens and P. syringae strains, due to the production of siderophores and antibiotics. In field trials, both the two antagonistic strains and chemicals, especially the antibiotics, reduced the size of the populations of INA bacteria present on leaves as well as the amount of frost damage to leaves and heads.