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.
NOTE: Apply dormant sprays only when the temperature is above freezing and before buds show green tips. Borers that attack apple and pear trees are controlled by the spray schedule above if the trunk is thoroughly sprayed. If borers have attacked young, nonbearing trees, spray the trunks every 2 weeks during June and July with a multipurpose fruit spray.