Cereal plants gain chemical potential energy as they grow. which form of energy is converted to create the chemical potential energy?

The solar energy is converted into chemical potential energy.

The cereal plants gain energy from the sun and carry out various chemical processes to form their food via the process of photosynthesis. They take carbon dioxide from environment and using water and su light produce the food and release oxygen gas in the environment.
Therefore,this energy is stored in it as chemical potential energy.