الفهرس 
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Abstract
Neem and Chinaberry are two trees belonging to the family Meliaceae. They both exhibited many economic therapeutical uses. In addition; they are an important source of botanical insecticides by the chemical been in them as tetranortriterpenes. Environmental pollution can be reduced as these substances are not toxic, safe and biologically degradable without any enough residues.
Each of the two trees has a noticeable problem in their
gennination. Neem seed suffers from being deteriorated in it:- viability by time, which can be reduced to almost 13% after onl·,r two months. Chinaberry (Melia) seed exhibited hard seed coat which affects its germination. The germination rate takes more than
40 days.
Two experiments were carried on Neem and Melia seeds during the period from 1993 to 1996. The first was on the effect of presowing treatments on seed gennination of the two trees, the main treatments were soaking in tap water for several days, in hot water (50 °C/30min) and in GA3 at different concentrations for neem seed. Melia berry was treated with the same manner in addition to concentrated sulphuric acid. The second experiment was on the effect of seed age on gennination parameter of the two species. Neem seeds were stored from ripening till60 days and sown at intervals of 15 days. Melia berries were collected on March and sown monthly from April to August.
Soaking in tap water and in GA3 gave the higher gennination percentage. Melia seed coat hardiness can be overcomed by soaking in sulphuric acid. Neem seeds; which were stored from ripening to 60 days showed germination percentage begins from 100% and decreases by age. Stored Melia seeds showed an increment in germination percentage till 90 days then afterward decreased. Moreover the gennination rate and seedling height go parallel to germination percentage.