In flowering plants, the megagametophyte (also referred to as the embryo sac) is much smaller and typically consists of only seven cells and eight nuclei. This type of megagametophyte develops from the megaspore through three rounds of mitotic divisions.t consists of three parts: The integument(s) forming its outer layer(s), the nucellus (or remnant of the megasporangium), and female gametophyte (formed from haploid megaspore) in its center. The female gametophyteâspecifically termed a megagametophyte âis also called the embryo sac in angiosperms.
Late winter or early spring is the best time to begin spraying an apple tree. Using horticultural oil spray helps to destroy any insects and their eggs on the tree before new growth begins.
When deciding when and how to spray your fruit trees, be aware that many domestic insecticides also affect beneficial insects such as bees. For example, carbaryl, malathion and permethrin are toxic to bees and other harmless insects.