Feminized seed is just as it sounds, a seed lot that produces predominantly female plants through chemical induction. A higher proportion of female plants is desirable since females are the source of almost all the economically significant products, whether seed or flower.
Feminized seed is created by inducing female plants to become hermaphrodites by applying chemicals like silver thiosulfate (Lubell and Brand, 2018). Hermaphrodite plants have female flowers, which accept pollen to create seeds, and male flowers, which release pollen. The theory is that chemically induced pollen produced on a female plant contains the female sex chromosome (X chromosome) rather than the male (Y chromosome). Thus, the progeny seed created by pollination with a hermaphrodite will inherit an X chromosome from the pollen and an X chromosome from the ovum of the female flower. The resulting seeds will be primarily females, but there is not yet a method that consistently produces 100% females. This has implications for production using feminized seed (see the Agronomy section of our website).
The most significant handicap of feminized seed is chemical feminization – it makes no further seed to multiply. Therefore, it must be reproduced season by season; it’s not scalable. Chemical induction of feminized seed is most appropriate for horticultural, craft-style production of flower products.