This pea pod or fruit develops after takes place during reproduction in a flowering plant

Fertilization.

Explanation: The male and female gamete fuse together to form fruit. After pollination and fertilization the carpels develops into the fruit.

The growth of fruit is initiated by the growth regulating hormones which is produced by the developing seeds.

The carpels develop into fruit so the number of carpels in a flower determines the degree of pollination and fertilization.

as resources become scarce because of population growth, the growth decreases after few years due to lack of resources and food.