In early 2000, many banks began to apply different processes on how to make feminized cannabis seeds
The process to obtain feminized seeds was a revolution in the cannabis sector since growers could trust that all their plants would be females, without the need to differentiate males from females and without having to remove the males that could spoil the crop, It offers a number of advantages of considerable importance.
Not surprisingly, feminized seeds now represent almost all of the seeds that are sold, as they offer a number of important advantages for the domestic, professional or breeder of new genetics, regardless of whether you prefer photodependent plants or autoflowering seeds. The great disadvantage of this method is well known: the grower who acquires feminized seeds cannot make his own seeds because he does not have males. Therefore, the only way to do this is through the same process with which this type of seed is obtained. How to make feminized cannabis seeds, what are these processes and what are they based on?
Therefore, the only way to do this is through the same process with which this type of seed is obtained. What are these processes and what are they based on? Feminized seeds are born from a process by which the sex of a female is reversed, that is, it is forced in different ways to produce male flowers.
In this way, and once in bloom, the female chosen for the reversion of sex will begin to form what we know as male flowers, which, as in male plants, will release the pollen that will fertilize the flowers of female plants. What is the difference between a male and a female reversed?
The sex of cannabis plants is determined by the so-called sex chromosomes or gonosomes. Male plants have a pair of distinct sex chromosomes called “XY” or heterogametic, and the chromosomes of females are the same and called “XX” or homogametic. By crossing a male (XY) with a female (XX), we obtain approximately half of male plants and half of female plants.
But if we cross two female plants (reversing the sex of one of them to force it to produce pollen), the result will be seeds that will produce female plants, since only female sex chromosomes have entered the equation. If crossing XY with XX we obtained 50% of each (males and females), crossing XX with XX we obtain plants that only have chromosomes XX, that is, plants that are females.
As much as we turn a female into a male, what we can’t do is change her genetic makeup, which remains female, XX. In this way, the pollen produced by this plant will exclusively transmit female sex chromosomes XX.
As we have explained, the question of how to make feminized cannabis seeds is based on a process by which the sex of a female is reversed, that is, it is forced in different ways to produce male flowers. Therefore, and once in bloom, the female selected for the reversion of sex will begin to form male flowers that, like in the male plants, will release the pollen that will fertilize the flowers of the female plants. What is the difference between a male and a female reversed?
Although the expression “reverse the sex of a plant” is used, it is not really what is done, since the sex chromosomes of the female plant (XX) have not changed even if we get it to produce male flowers. The process of changing the sex of female plants is achieved in several ways, but always with the same objective: to reduce the level of ethylene in plant tissues and / or inhibit the action of ethylene, which causes the plant to generate male flowers upon flowering as if it were a regular male. And is that ethylene is a natural regulator of sex in plants.
Let’s see the process to obtain feminized cannabis seeds and what are the most ways to reverse the sex of female plants to produce feminized seeds.
How to make feminized cannabis seeds?
There are different ways to get a female to produce pollen, and almost all of them need some chemical that is usually sprayed on the female plant that wants to reverse sex. Once sprayed with the chosen product and under a flowering photoperiod, the plants will begin to bloom normally, but as males instead of as females, producing pollen that only contains XX chromosomes and that can be used to pollinate other females and produce feminized seeds . These are some of the most used techniques.
Controlled stress or rodelization
One of the first systems used to obtain seeds that produced female specimens was controlled stress or rodelization. There are several ways to stress cannabis plants to get them to generate male flowers, such as stress due to temperature, nutrition, photoperiod or PH. But supporters of this technique choose to delay the time of harvest 2 or 3 weeks, which means that the plants produce a few male flowers without forcing them to stress as hard as they should with any of the other techniques. With this system the amount of male pollen that is achieved with other systems, such as the STS, is not achieved. It will be enough to produce a handful of seeds and that the domestic grower can try to make his own feminized crosses.
The great advantage of this technique is to be 100% natural, not requiring any type of chemical during the process. It is an excellent alternative for those who only want a few seeds and do not want to complicate their lives with formulas and laboratory products. However, it is the only method we present with which there may be a higher rate of hermaphroditism in the offspring.
This is another process to obtain feminized cannabis seeds, using a solution of colloidal silver at about 30ppm (available in pharmacies or online) in distilled water. You have to repeat the applications for days until the plant produces male flowers, something that does not happen with the STS, with which almost always a single application is enough. Colloidal silver is made up of electrically charged silver nanoparticles and has antibacterial and antifungal properties. This process to obtain feminized cannabis seeds appeared in the industry in 1980 for therapeutic purposes. We must discard the plants sprayed once the pollen is harvested, because colloidal silver is absorbed systemically and remains in the plant tissues.
It is a process to obtain feminized cannabis seeds studied by Mohan Ram, who conducted extensive research on the reversal of sex in plants also with STS. According to him, sodium thiosulfate (STS) would be more effective in producing viable male flowers and pollen in female plants, achieving better results. Normally, silver nitrate is mixed with sodium thiosulfate instead of using it in isolation.
Gibberellins are hormones produced by plants that help them regulate various processes related to their development. There are several types available in the market, although the most common and effective is gibberellic acid or GA3 (gibberellin GA3). It is used very similar to colloidal silver, being sprayed on the plants we choose for the reversion of sex for several days before changing the photoperiod to flowering. One of the side effects of gibberellic acid is a very strong spike in the areas of the plant that we have treated, so do not be surprised if it happens to you. The recommended dose to achieve the best results is around 100 ppm.