An essential requirement of agriculture is to understand how plants grow and reproduce.The earliest practitioners of crop production some ten thousand years ago had to learn to plant seeds and to keep them alive through watering and cultivation. Man eventually invented tools and machines that made farming more efficient and learned about plants themselves, leading to the development of crops that were of greater human benefit. The science of botany evolved from humankind's desire to know how plants live and reproduce. Their reproduction systems are functionally similar to those of animals. Most plants grown for agriculture have their sexual organs in their flowers. Whether the plants cross-pollinate or self-pollinate, it is essential that fertilization takes place for the production of seeds.

In the 1500s, German botanist Valerius Cordus (1515-1544) used the word pollen, Latin for powder or fine flour, to describe flower dust. In 1592, a...