Abstract
Study was conducted to test an effect of microorganism which was mainly composed Trichoderma sp to prevent White root rot in the University farm from 1991 to 1994. Japanese pear ‘Shinko’ trees were classified no infected and infected White root rot by observing and judging roots digged out from soil. No infected and infected tree ‘Shinko’ were used.
Results as follows:
1. Continuity application of microorganism soil conditioner gave vigorous root growth on no infected trees. Soil conditioner stimulated the growth of trees and a lots of shoot was became moderate and long shoots. Continuity application of soil conditioner gave effects to increase very large fruits, which were more than 451g weight.
2. By using soil conditioner to infected trees, trees became vigorous even after two years of treatment.
3. After three years of treatment white root rot were found at middlesize of root in infected trees. But next year no extend of infection was found.
It is concluded that the annual treatment of microorganism soil conditioner is shown the material which have high function on preventing White root rot. The soil conditioner give vigorous to Japanese pear tree, especially to roots and shoots.
