explain dwarf varieties in wheat and rice?

Answer 1

In a monoculture, there is no particular advantage in being tall. Nobel Peace Prize winner Norman Borlaug had the idea that cereal grasses could be bred that would have as many leaves but shorter stems than existing cultivars. Since these dwarf varieties don't have to expend energy being tall, they can devote that excess energy to higher grain production. Thus, high-yielding dwarf varieties were adapted worldwide. Countries such as India and Mexico went from being grain importers to being grain exporters (see Green Revolution).

Answer 2

there are many cause for the dwarf varieties in wheat and rice :

. by using pestisides, DDT in agriculture fields and this causing less fertility.

. Due to pollution which is causing depletion in ozone layer.

. Sufficient water is not aviable for rice.