Effect of pollen parent on certain aspects of fruit development of Hillawi date palm (Phoenix dactylifera L.) in relation to levels of endogenous gibberellins

The effect of two pollen parents (Khikri Adi and Ghannami Akhdar) on certain fruit characteristics of Hillawi date palm (Phoenix dactylifera L.) was investigated in relation to changes in levels of endogenous gibberellins during fruit development. The results showed that, the pollen parent Khikri Adi caused a highly significant increase in fruit size, fresh weight of the whole fruit, pulp and seed in comparison with fruit produced by the pollen parent Ghannami Akhdar. The pollen parent had a significant effect on the levels of free gibberellins, with fruits produced by the pollen Khikri having the highest level, as compared with fruit produced by the pollen Ghannami Akhdar. The levels of endogenous gibberellins were low at fruit set (5-7 weeks from pollination) but rose to a peak value during maximum fruit growth rate (9-11 week from pollination) and then declined as the fruit an advanced toward the stage of physiological maturity.