Yes it’s similar to fruit trees etc… (fruits are only to carry seeds)
If you have an apple tree, it will only yield a certain weight of fruit each year… so if you thin the baby fruits by removing half… the apples you get at the end of the season should be twice the size! -and for flower shows, people will remove most of the buds and sideshoots from their Dahlias or sweet peas or whatever to get big, quality flowers because more of the plant’s energy will go into what is left.
obviously you can’t remove half the seeds forming in a cannabis plant… but by the same principle a lighter pollination will do the same job.
VG
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make sure they are very dry before freezing them. a few weeks in the open air or use silica gel.
when you have to take the seed stash out of the freezer… make sure you let the whole sealed container (with all your bags/vials of seeds inside) warm up to room temperature for an hour or two BEFORE you open it. This avoids condensation forming on the bags of seed which will happen if you let the air get to them whilst they are too cold. Providing the seeds were dry/cured before you put them in the bags/vials, you won’t get condensation inside them because they are dry inside and sealed.
VG
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One last thing to mention about seed viability… Seeds need a while to dry out and the seed cases to cure, and the germination rate will increase as this happens. If you ever try to germ them straight off the bud you may get rates that are worse than you expected.
Providing they have been kept properly, seeds reach their maximum germination rates between the ages of 1-2 years. (not true for every type of plant but true for cannabis and most plants)
VG
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I would like to add that temperature plays a large factor in the seeds development time as well.
Cold/Cooler climate can cause the seeds to take much longer to completely mature.
Warm temps can actually increase the speed at which they mature.
If your room is cold you could harvest the seeds at the recommended time, but still find many seeds that haven’t fully developed yet.
Warmth will help the Fertilization process be faster as well as decrease the time it takes for the seeds to mature.
So make sure to keep an eye on temps.
So the pollen grain will hit the pistil and then begin to GERMINATE.
It sends out a tube towards the base of the pistil like a root, in order to reach the ovule.
After it gets there it begins the FERTILIZATION process.
Once pollen makes contact with a pistil it takes about 20+/- minutes for the GERMINATION of the pollen grain to happen.
FERTILIZATION however can take up to 2+ days in COLD temps.
After the fertilization you will see the pistil wither and it will change from white to red or brown as it dies.
In addition, if the pollen has been exposed at all to EXTREME heat, HUMIDITY, or MOISTURE, it will NOT Germinate properly and the pollen grains “tube” will die before it can fertilize the pistils ovule.
So no seeds.
So if you spray or mist after you apply pollen, I would wait at least that 20 mins (I would wait an hour or so to be safe tho) before misting everything down to destroy any loose pollen grains.
Or at least be careful not to hit your freshly pollinated girls in that time.
†
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You may but you also may have a strain that doesn’t need that, e.g whose ancestors grew in a climate where “dry” is not even a concept. 
Lots of good things in this thread, bookmarked!
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I am going to give my ignorant version about this… For now I only make seeds one time… All the plants where almost the same size, but different strains: Wild Thai, Pink Floyd, MangoWidow and Bubblegum. All crossed to a Pink floyd male. They were all started 12/12 at the same time.
I let all them all the time that I think that was necessary… About 10 weeks more or less…
Results: The plants that give the most number of seeds was Pink Floyd and Wild Thai. The difference in size is that the WT is double the size (or more) of the PF seeds, all well developed. One of the PF was moved to 18/6 seeded, to make a test of they will develop this way, this plant has many less seeds that the others, but the end size of the seeds was the same.
So I think that the size of the seeds depends mostly on the strain. I am not saying that this discards that the size is affected also by the size of the mother plant or by the quantity, only that is one more thing to consider.
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you are right that seed size varies with strain, Chem seeds tend to be very small, for example, and Deep Chunk seeds are massive! , usually plants with fewer calyxs like DC or bubba will yield fewer, larger seeds for sure.
BUT what i say about quality seeds and seed yield still stands… there will be an optimum amount of decent seeds you can get from each strain, of course size of plant will also be a variable along with lots of other variables.
VG
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Thanx Gypsy!
Gypsy ???
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Confused Stoner Moment???
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ahhhhhh i float all my seeds till they sprout, but if your just trying to separate the light weight ones from heavy ones the easier to do with a bowl or slanted tray and just blowing across them while shaking them, heavies will stay low and lights will either get blown out or off, or will congregate in a top line above the viable seeds.
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Yeah, a few minutes in a glass is really short for a test. Some older well dried beans can take much more time before being rehydrating and sink.
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Nice thread @Zanzibar
I can follow and agree on your conclusion. I found out that there must be of course a genetic relation beside all this temp, rhl, nutrition stuff.
Fun fact:
I thought like a decade or so that seeds are always bright and not beautiful xD then 10 years ago I got gifted the first pack of private seeds- dark and marbled AF…
This was mind opening 
Happy Sunday
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Yes, I also do “float tech”.
And some seeds need more time to rehidrate depending on age and shell hardness/permeability.
For me, the float: discard, sink -good is not a good test for viability.
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I have a question: How many times can a seed be thawed and refrozen? 
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You can thaw and refreeze them as many times as you’d like. If they survive the excercise is another question 
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Good question @Magu
There is not (as far as I know) a specific answer to this question, except that each time you thaw and then re-freeze a seed you are lowering its viability.
That said, one thing that everyone should do is make seeds, and then, experiment with them. It’s fun!
Make a batch of seeds, set 50 in a freezer, every few months thaw them out and then re-freeze them again, and see what happens. Test the viability along the way, and note ratios/if they diminish in viability.
And then, please, post your results
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Here’s some info from a paper, which is pretty much consistent with the conclusion of other papers before it as far as the relationship of Nitrogen to hemp seed production:
Nitrogen fertilization impact on hemp (Cannabis sativa L.) crop production: A review
Navdeep Kaur, Zachary Brym, Luis Alberto Monserrate Oyola, Lakesh K. Sharma
First published: 28 March 2023
4.2 Seed production
Hemp seeds are a highly nutritious, reliable source of proteins, unsaturated fats, fiber, and minerals such as Mg, Ca, Na, Fe, P, and zinc (Zn). Oil is extracted from seeds containing up to 90% of unsaturated fatty acids. N application has shown variable effects on seed weight. According to one study, the increase in N rate from 0 to 240 kg ha−1 showed no significant increase in the mean seed weight. Another study found that seed weight is influenced by cultivars, with some (e.g., Finola) consistently producing larger seeds than others (e.g., Fasamo). Moreover, increments in N rate were associated with a seed weight increase in the Finola cultivar (maximum with 66 kg N ha−1) and a decrease in the Fasamo cultivar.
Seed yield also depends on the interaction among weather conditions, genotype, and N rates. Seed yield has been reported to show quadratic and linear responses to N rates depending on the cultivar Malvetica. Researchers observed that during unfavorable weather conditions (i.e., hot temperature and unevenly distributed rainfall during the seed filling stage), seed yield was not significantly affected by the N application from 0 to 120 kg N ha−1. Drought-like conditions cause low dry matter accumulation and reduced seed weight and biomass. Overall, seed yield is a complex trait: genetics contribute 28%, the environment contributes 25%, and genotype into the environment contributes 35% of the variance. This signifies that we can control a maximum of 60% of the variation in grain yield by improving environmental conditions such as better N management.
Besides affecting the overall yield, N affects seed protein and oil content. The seed protein and oil content are increased by increasing N rates, but the magnitude of the increase in protein and oil content depends on the cultivar’s genotype. Vera et al. found that the cultivar Finola showed an increase in oil and protein content with an increase in N rate. In contrast, cultivar Fasamo’s oil content decreased with an increasing N rate showing the inverse relationship between seed oil content and seed protein. These studies suggest an interaction among N fertilizer rate, genotype, and weather conditions during seed production.
So increasing N seems to help production of seed, with factors like which cultivar and watering schedules (environment). I have not found a paper that talks about the timing of pollination as all papers’ research is done in fields with males and females present = naturally timed pollination.
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I try to do it as little as possible… but ive had seeds in the freezer for at least 10 years that have been taken in and out again a few times a year and they have no noticeable drop in germination rates.
My take on it is that if the seeds are dry and dormant (the dryness is pretty much the most important thing) then i don’t think the simple action of thawing/freezing them is going to harm them - except that they will just deteriorate faster for the time they are out of the freezer.
I only ever have mine out of the freezer for a few hours - long enough to warm up and avoid condensation when you open the box (as described above)
Garden Organic | Seed Storage for longer life.
“Cool and dry are the two ideals for most of the seed we are concerned with. As a rule of thumb, the storage life of a seed is doubled for every 5˚C drop in temperature and 1% drop in moisture content. There is a limit, though, and freezing and ultradrying can be harmful. Home growers should aim to achieve 5% moisture content and then storage in a domestic fridge or freezer will suffice.”
this link is quite good
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Thank you for the knowledge bombs @VerdantGreen !!! Great to see you on here!! Your Bubba work is legendary 
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