Abstract: Over the past three consective years from 2010 to 2012, we have been taking application test which used the multi\|function Streptomyces TOR3209 as the primary biological organic fertilizer on pear trees for more than 25 years. The results showed that TOR3209 could promote the growth of old pear trees, which was reflected in the significant increase of regeneration roots and capillary roots; leaves increased in thickness and leaf biomass, the color turned from yellow to green, and the content of chlorophyll increased by 14.6%; the quality of fruits improved largely, that the content of soluble solids increased by 6.3%, and the firmness of fruits increased by 10.8%; the diversity of culturable bacteria in roots and rhizosphere soil also increased significantly. From above, we can drew the conclusion that multi\|functional biological organic fertilizers contributed to repairing and improving the growth of old pear trees through rhizosphere ecosystem, it had an expansive application prospect in the field of orchard improvement.

Key words: biological organic fertilizer, old pear trees, growth, quality, bacteria