Plant Reproduction and Germination

Weedicides should be sprayed during the vegetative growth stage of weeds but before flowering. This timing prevents weeds from producing seeds that would infest the field in future seasons. Spraying after flowering is less effective as seeds may already be mature, and spraying before crop emergence risks damaging the crop itself.

 Seed germination requires both water and oxygen

The suspensor cell situated at the terminal end of suspensor in contact with a globular proembryo.

An outgrowth of integument near the micropyle of the seed

In some seeds such as black pepper and beet, remnants of nucellus are also persistent. This residual, persistent nucellus is the perisperm.

The reproduction in phanerogams occurs by seeds. 

These have male reproductive organs in one individual and female in another like gymnosperms.

Generally, it is the seeds of the plants which are used to extract oils. For example: seeds of mustard, linseed, etc.

A bi-or tricalpellary syncarpous unilocular ovary having one ovule at base represents the basal placementation.

An embryo may sometimes develop from an embryo sac other than egg. This is called apogamy. It is the development of an embryo without fertilization; especially the development in some ferns of a sporophyte from the gametophyte without fertilization.

The slimy green patches growing on the surface of ponds are known as algae. These algae reproduce and multiply in ponds by fragmentation and turn the whole pond green.

Massive bamboo flowering provides a sudden, abundant food source of nutrient-rich seeds for rodents. This triggers a rapid surge in the local rat population, which subsequently leads to crop destruction and famine, a phenomenon known locally as mautam.

Secondary dormancy occurs in some non-dormant and post dormant seeds that are exposed to conditions that are not favourable for germination, like high temperatures. It is caused by conditions that occur after the seeds have been dispersed.

Non-recurrent apomixis is where an embryo arises directly from a normal egg-cell without the process of fertilization. Egg cells are haploid and hence, the resulting embryo is also haploid. It includes haploid parthenogenesis, haploid apogamy and adrogamy.

Barochory or the plant use of gravity for dispersal is a simple means of achieving seed dispersal. The effect of gravity on heavier fruits causes them to fall from the plant when ripe. Fruits exhibiting this type of dispersal include apples, coconuts and passion fruit, and those with harder shells.