| Abstract | Two trials to evaluate the performance of 20 provenances and one land race of Azadirachta indica A. Juss (neem) from 10 countries were established in January 1996 at two contrasting sites in Tanzania. Assessments were carried out at the ages of 17 and 53 months after field planting. Both assessments involved survival, root-collar diameter (RCD) and height while branch number, leaf mass, foliar nitrogen (N) and phosphorus (P) concentrations and contents were assessed at 17 months only. At all assessment occasions except for survival, significant (p<0.05) variation among the provenances was detected for the tested parameters. Overall, the Ban Nong (Thailand), Vietianne (Vietnam), Ban Bo (Thailand), Ramanaguda (India) and Doi Tao (Thailand) were the best performing provenances for Chamwino site while for Mkundi site, the best performers were Doi Tao (Thailand), Ban Bo (Thailand), Ban Nong (Thailand), Ghaati (India) and Vietianne (Vietnam) provenances. These provenances should be used asseed sources and for the establishment of pilot plantations in the respective sites and other areas with similar environmental conditions. |