Study on the Growth Pattern of the Azadirachta indica Young Plantation

Annual growth rhythm, growth pattern of height and caliper of young trees of Azadirachta indica were studied. The results indicates that the annual sprouting period can be divided into 3 stage: spring phase (from February to April), summer phase (from June to August) and autumn phase (October). According to the growth dynamic of height and caliper, the young trees grows rapidly in the first year after being planted, growing slowly in the second year, and then growing evenly in the third to seventh year. The annual growth patterns of height and caliper showe that the growing period is 6 months (from April to October), and begin to grow rapidly from May to October. The height growth in two months (July and August) reaches 62.1% of the year's total. Correlativity of the monthly mean temperature to the growth of height and caliper, and rainfall to the growth of height are striking. The temperature has more important effect on the height growth than the rainfall. The survival percentage of young neem plantation is very high. 53.3% of trees fruited among 2 years plantation and 93.1% of them fruited in 4 years plantation.