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The Science of Feminised Cannabis Seeds

How did we get to feminised cannabis seeds?

In Greek mythology, Hermaphroditus, the son of Hermes and Aphrodite, was fused with a nymph, Salmacis, resulting in one individual possessing physical traits of both sexes.

Hermaphroditism is a natural trait that occurs spontaneously in cannabis plants in the wild as a final emergency response to the absence of either sex in a colony. The mechanism allows the plant to self-pollinate by producing both female and male flowers.

The Science

Most dioecious (distinctively male or female) plants have apparently evolved from hermaphroditic ancestors, so the trait remains partly active in many species of plants. Although this trait prevails in many pure sativa lines, it has been largely outbred from modern commercial hybrids.

Usually, it’s the female plants that produce staminate parts, although reversal of both sexes has been reported by growers.

Seemingly normal dioecious plants can display this trait when they are grown in unfavourable environmental conditions. Some examples of things that might affect the sex of cannabis plants include:

– High and low temperatures
– ph fluctuations
– Plant hormones
– Light leaks in the grow room
– Water-related stress and overfertilization.

In this sense, there are no true males or females, only dioecious plants with a greater or lesser potential for the dual-sex state.

Developing feminised genetics

Female plants will most likely turn if they are genetically prone to the condition. Once turned, the females will form modified or incomplete pollen sacks that look like tiny bananas.

The change often goes unnoticed because the bananas start growing right out of the bud, and they are difficult to spot with the naked eye. The pollen from these hermaphroditic females can either be fertile or sterile.

If the pollen is fertile, she usually pollinates all the plants in the grow room, effectively ruining the entire sensimillia crop. Plant stability is measured by how much stress they can handle, and highly stable female plants will not turn into hermaphrodites no matter how much environmental stress you subject them to.

These are the females that we are looking for when we want to make feminised cannabis seeds.

And then what?

Generally speaking, hermaphroditism is considered an unwanted trait in drug strain cannabis plants. The trait is dominant in its expression, which means that any parent carrying this trait will pass it on to its offspring. There are, however, some uses for this trait, which include making feminised seeds.

By removing the Y chromosome from the equation, we are left with nothing but female offspring. These seeds exist in the first place because they remove the need to sex the plants before flowering them, which can save growers a lot of time and trouble. Unwanted male plants take up much-needed space in the grow room, and female clones need a lot of care. Feminised seeds eliminate those problems because they will produce female plants 99% of the time (the remaining percentage makes room for spontaneous genetic anomalies).

The main concern with making feminised seeds is that to create them, we must allow a hermaphroditic female to pollinate itself or another female plant for the offspring to carry only female genes.

This is problematic because we don’t want the offspring to become hermaphroditic as well. The females that are easily pushed towards hermaphroditism are usually removed from the grow room before they have the chance to pollinate themselves and other females. Seeds from these plants are usually highly unstable and produce one generation after the other of mostly hermaphrodites. Not exactly what we are looking for.

So only the most stable and tolerant plants will be eligible for making female seeds. We are looking for only the slightest expression of this trait; anything else would defeat the purpose of what we are trying to do. Using only relatively stable females for our feminised cross, we decrease the chance of getting hermaphrodites further down the line.

After all, we want a constant supply of normal and stable female plants suitable for indoor cropping, not a bunch of hermaphrodites pollinating each other all over the place.

Feminised cannabis seeds production

We start by manipulating the environment to find the plants that can handle the greatest degree of stress without any significant adverse effects. The more they can handle, the better. This screening process is crucial for creating stable female seeds. Using two plants, one normal and one hermaphroditic female will give us the best result because we recombine genes from both the female parents, while self-pollination is basically inbreeding.

Self-pollination is sometimes used to isolate traits in rare female clones that would otherwise be lost. Still, it might also give rise to genetic depression, mutations and all sorts of physical disorders. In both cases, the offspring will carry only female genes, but the seeds from the selfed female would be genetically less diverse and might result in fewer healthy individuals. Naturally, the normal female used in our cross would also have to be stress-tested and proven stable for good results.

Once we have found a strong female candidate, we can start making feminised seeds. We need a catalyst to start the process, and silver water is usually administered to the female plants at this point. The stress from the tiny but toxic silver particles is just too much for the female to handle, so she responds by reverting to the dual-sex state and starts producing male flowers.

Another way to produce feminsed cannabis seeds

There is also another method for creating feminised seeds called rhodelisation, which was developed by the breeder Soma.

Rhodelisation means that you allow a female plant to flower for an unnaturally long period of time for it to produce a few male flowers. Remaining unfertilised late in the season constitutes a problem for the female plant, so she tries to self-pollinate to preserve her genes.

This method is substantially more time consuming, but it provides a natural way of producing feminised seeds without subjecting the plants to extreme stress levels. It is, however, not an alternative if time is a factor, and that is usually the case. This method takes about twice as long to complete, depending on the flowering cycle of feminised strain.

High-quality commercial seeds from feminised plants should, therefore, in theory, give rise to mostly normal females that are resistant to the hermaphroditic condition. This is what we can hope for, but it’s not always the case.

Different breeders use different methods, but usually, there won’t be any problems if the plant grows near-optimal conditions. Stress is the trigger that launches the hermaphroditic trait, so there is always a degree of caution when growing these plants. Keeping a close eye on them is essential.

On the positive side, feminised plants are a breath of fresh air because the problem of identifying females and hoping for as many as possible is eliminated.

If 10 female seeds are planted, 10 female plants will grow.

Seedsman has thousands of feminised cannabis seeds for sale from dozens of different breeders across the world. If you’re only interested in optimising your grow space, then you’ve got so many options. Happy harvest!

Cultivation information, and media is given for those of our clients who live in countries where cannabis cultivation is decriminalised or legal, or to those that operate within a licensed model. We encourage all readers to be aware of their local laws and to ensure they do not break them.

This post is also available in: French


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