The influence of stage of seed maturity, moisture content and storage temperature on the survival of neem (Azadirachta indica) seed in storage

Neem seed extracted from fruit harvested at two stages of maturity (referre d to as ripe and fully mature) were stored at three seed moisture contents (mc) (undried, <15% me, <10% me) and in three storage conditions viz. an ai r-conditioned room (22 degrees C, 76% relative humidity), refrigerator (3 d egrees C) and freezer (-20 degrees C) in sealed thick polythene bags. The g ermination of the undried ripe seed was high (86%) and remained above 80% w hen seeds were dried to 13.2 and 7.1% me whereas the low germination (46%) of the fully mature seed fell to around 30% after drying to 14.2 and 8.1% m e. At all seed mcs the loss of germination during storage occurred most slo wly in the refrigerator followed by the air-conditioned room. With the exce ption of seed having <10% me, storage in the freezer was highly damaging. T hus after 5 weeks storage at 13.2% me the ripe seeds had germinations of 65 %, 52% and 0% when stored in the refrigerator, air-conditioned room and fre ezer respectively. Reducing the seed me prolonged the storage life of both ripe and fully mature seeds in all three storage conditions with the result that the germination of ripe seed remained above 50% for 24 weeks when the seeds were stored at 7.1% me. These results are discussed in relation to t he classification of neem as a recalcitrant, intermediate or orthodox seed.