Why do some papaya flowers not bear fruits

Flowers are the reproductive parts of most of the plants. There are two types of flowers based on reproduction. These are bisexual and unisexual flowers.  

*A unisexual flower either contains only stamens which is called as male flower or it contains only pistil which is then called as female flower.e.g.Papaya.  

Hence, papaya plant bearing male flowers will not have any fruits.

materials water oxygen those are the things i can think of in this moment.