Flowering synchronization between the restorer (R) line (Giza 178) and cytoplasmic male sterile (CMS or A) line (IR58025A) in hybrid rice seed production plot is very needed to achieve greater seed yield. Twoyear experiment was carried out at the Experimental Farm of Sakha Agricultural Research Station, Kafr El-Sheikh, Egypt in the 2020 and 2021 seasons. This study aims to examine the effect of male to female ratio (2R:10A, 2R:12A and 2R:14A), male direction (one way and two ways) and

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... s in days in flowering between male and female (five, two days and without differences) on productivity of hybrid rice seed. A split split-plot design in three replications was utilized. The main plots were the male to female ratio, while male direction was arranged in the sub plot sand the differences in days to flowering were located in the sub-sub plots. The obtained results showed that plant height, panicle exsertion percentage, panicle length and flag leaf angle were not significantly affected by the male to female ratio, male direction and differences in days to flowering. On the other hand, the number of panicles hill -1 , panicle weight, seed set percentage, seed yield and harvest index (%) were highly significantly affected by the male to female ratio, male direction and differences in days to flowering. The highest values of seed yield (2.432 and 2.521 t ha -1 ) were obtained when using the male to female ratio 2R:14A, two-way male direction and without differences in flowering.