sentences:  It has been identified that it is possible that habitat modification or exclusion may also play a role in the effectiveness of the antibiosis of the fire blight biological control.Environmental factors influencing the growth and spread of "Pantoea agglomerans" include winter chilling, good sunlight exposure and quality air circulation.Fruit-bearing trees, such as apple and pear trees are common Pantoea agglomerans hosts and during blooming season the fruit-bearing trees receive a period of chilling to revive them from their dormant state in the following Spring.