Hybrid Corn pollination can only be done by an expert breeder. Breeders produce hybrid cord seed by cross-pollinating inbred lines.
Inbred lines are produced by self-pollinating (pollinating silks with pollen from the plant's own tassel) selected plants with desirable characteristics.
Commercial hybrid production involves planting male and female inbred lines in separate rows in an isolated field where possibility of foreign pollen contamination are rare.
Hybrid corn produces dramatically higher yields than corn produced by open pollination.
That is why hybrid corn is getting more and more popular today. However in the long run it is the farmer will be at the losing end.
It is because the farmers will have to buy the hybrid corn seed from the breeder in every planting circle. They cannot keep the seed. Most of hybrid corn is patented and having them without buying it from the licensed breeder will be led to some legal consequences.