Harvest 1 seed from each F 3 plant. F 4 Same as for F 3 . F 6 Grow progeny of each plant in a separate row. F 7 Yield trials, etc. Requires little space or time in early generations, it is well suited for greenhouse and off-season nurseries.
Breeders can accommodate a larger number of crosses.
Has an advantage over bulk method if desired plant type is at a competitive disadvantage. Effective in improvement of traits with low heritability. Natural selection does not usually influence the population. Fewer field evaluations, therefore natural selection can not work in your favor. Modifications of SSD are sometimes used in breeding programs such as early generation testing.