For the most part radish seed growth is best when they are planted in cool soil; early spring or fall are the preferred seasons for many varieties. Next, be sure to get the soil in good shape before planting – loose, full of seasoned organic material, but not overly fertile. Moisture and soil depth must be right, too.
it will increase because even if we don't get as many children as 12-15 from one parent at least u can get 2 children for a parent so if u calculate like that if population today is 10 billion in the next 100 yrs it will be 20 billion