Metaxenic effects as related to hormonal changes during date palm (Phoenix dactylifera L.) fruit growth and development.

This work was carried out in Balteem area, Egypt on the ‘Hayany’ date palm cultivar. Spaths were pollinated using either one of the two selected males (M1 and M2). Fruit samples were taken at different stages of its development to determine the changes in IAA, GA and ABA content. Data indicated that there were obvious differences in ‘Hayany’ fruits that were produced from the two evaluated males. The concentration of the different growth regulators in consideration (IAA, GA, ABA) as well as the timing of their increase or decrease was also available between the two males. M1 maintained a higher level of IAA than M2 in most sampling dates. The highest IAA content coincided with rapid fruit growth. Moreover, M1 had higher GA content in most sampling dates especially in the 5 th and 6 th sampling date. This period coincided with the rapid growth phase. It was also shown that M1 had a higher ABA content than fruit resulting from using M2. This was clear especially in the 4-7 th sampling date. A possible relationship between fruit growth and growth regulators content during fruit growth and development is