APRICOT EMBRYO-SAC DEVELOPMENT IN RELATION TO FRUIT-SET

The development of the embryo-sac was studied during the pollination period in an apricot cultivar, Moniqui Fino, in relation to fruit set. Almost 19% of the ovules examined over the whole period were malformed. In pollinated flowers the ovules matured from anthesis to eight days later when, for the most part, they degenerated. In non-pollinated flowers, the development was more gradual and even ten days after anthesis there were still some ovules receptive to fertilization. The effective pollination period (E.P.P.) was between two and four days and was limited principally by the rapid development of the embryo sac.