Good quality seeds are essential to grow a strong and healthy crop. Healthy seeds can be bought from trusted sources or farmers can produce their own seeds. In that case, seed selection can be used to improve the quality of seeds.
There are several diseases that are transmitted via the seeds. If seeds from an infested field are used to grow the next crop, these seed-born diseases will immediately cause serious problems. Seed selection should thus start by obtaining seeds from healthy plants.
Small, shriveled and broken seeds contain less nutrition for the developing seedling. By removing these inferior seeds, the farmer is able to grow stronger and healthier seedlings.
Even if seeds are selected carefully, they still may carry diseases. In these cases seed treatment (e.g. hot water treatment or chemical seed treatment) could be used to further improve the quality of the seeds.
While seed selection is mainly aimed at obtaining healthier seeds, it can be used also to maintain and improve the quality of the crop variety. In a crop field, there are always differences between plants. Some plants may have characteristics that are more suitable than those of other plants. During the growing season, the farmer can try to observe these differences and mark preferred plants with a ribbon or with a stick. During the harvest, the seeds of these plants can be reserved for growing the next crop. In this way, the farmer can slowly improve the quality of his variety.
The selection of these plants may be based on characteristics such as the size of the plant, color or size of fruits, number of grains per ear, etc. But selection can also be done to keep seeds of plants that suffered less attacks by insects or diseases.
In this way, the farmer will select at harvest time the best seeds to be kept apart for the next season. Still, just before starting the next season, it is recommended to select once more to remove seeds that are too small, spotted, deformed, discolored, etc.
For sowing only the very best seeds should be used.