The Biological Characters of Azadirachta indica and Result of Introduction and Cultural Trail

This is a brief description of the morphological characters. The ecological adaptabilities and the economical characters of three provenances of Azadirachta indica from different rainfall level have been studied: (1) Phonological phases are distinct; (2) The difference of some growth indexes such as survival rate, biomass, the number of branches with fruits and the ratio of genital branches to the total branches are remarkable; (3) The content of azadiractin in the seeds of three provenances are above 0.4%. According to the ecological adaptability and economical characters of trees, two of the three provenances from arid and semi arid regions excell than the provenance from humid region.