BIS95, an improved approach to fire blight risk assessment

摘要

Risk assessment systems evolve as new experience and knowledge is gained. BIS95 (Billing's integrated system, 1995) combines valuable facets of past and current approaches with an emphasis on simplicity and clarity. Its design allows for future evolution and it is flexible enough for local adjustments to be made so that it is applicable to all hosts in all climatic areas. However, for consistency and precision, certain rules need to be followed. BIS95 is simple enough for use by growers with smallholdings using simple meteorological instruments manually recorded. It is equally suitable for growers and advisors using automatic orchard monitors or official weather station data, with or without the aid of a computer. Whatever the source, weather data need to be regular, reliable and representative for the trees at risk from Erwinia amylovora. BIS95 must be used in conjunction with good field data, notably: blossom periods of hosts and alternative host trees [pome fruits, woody ornamentals], dates of wetting of open flowers by dew, mist or rain, dates of any storm or other damage to young green tissue or flowers and current disease levels. Other factors affecting inoculum potential, host susceptibility, spread risks and target numbers can also be important. Tests so far on the precision of BIS95 are promising.