Botanists started experimenting with seeds in the early 20th century and found that mixing the pollen from similar varieties of plants often increased the volume and quality of the harvest. Since then, most of the seeds used in agriculture and family gardens are hybrids. Hybrid seeds are not without their downfalls, however, and some voluntary organizations around the world have started movements to save natural seeds, also called open-pollinated seeds, to assure their long-term availability.
When seed producers create hybrid seeds, they use cross-pollination techniques to select the best characteristics of one variety, and then combine it with another variety that may have a deficiency in that characteristic but an advantage in another area. Once the steps to creating the hybrids result in what is called a pure strain, the seeds are harvested, packaged and sold to farmers and gardeners.
The issue of hybrid seeds carries with it some controversy. The groups who eschew the mass use of hybrid seeds point out that the seeds require more fertilizer and the plants may not be as disease resistant as natural varieties. Those who promote hybrids state that the yield is higher using hybrids and the crops are more dependable if the plants receive enough food and water. Hybrid plants do not have the ability to adapt to environmental changes because the seeds can be sterile or genetically unstable, decreasing biodiversity.
The cost of producing hybrid seeds adds to the cost of farming or gardening since plants grown from hybrid seeds do not produce reliable future crops. This translates to increased costs for both consumers and agriculturalists. In developing countries, this cost can be prohibitive, especially after a poor or failed crop from the previous year or growing season. When plants from hybrid seeds pollinate other varieties of a plant species, the resulting seeds will also be undependable producers for subsequent crops.
Often hybrid seeds created for mass planting contain toxic coatings to retard fungal infections. Some of the seeds are encased in insecticides. Home gardeners using these seeds without protection can ingest the coatings through physical contact or by inhaling the dust. Side effects of fungicides can be serious. Unlike natural seeds, treated seeds cannot be used as animal feed and the containers used to treat the seeds or to package them cannot be used to store or consume food.