Let’s talk dirty, sorry dirt.
This phenomenon is directly linked with the regime of the plants producing these seeds, simply. To prevent it, i just germinate my own seeds ^^ I know it’s a shitty answer. But it’s important to know that you can even lower as fck the viability of seeds (short term and long term) just in feeding “badly” the mothers. They have to be well fed during the process (without burning them or to create blueish K patch either), the level is not so the problem, it’s more about what is in the soup. The simpler and the more NPK-balanced the better. And no it’s not because you’re in organic or supersoil that you necessary prevent it.
It’s too risky to throw a generic rule in considering the big difference from one nutrient’s line to another etc … but i’ll try to give a secure lead :
-
better to use a cheap base ratio of 1:2:1 (even granulates for the garden, no joke) that stacking complete interactions engineered for flower’s production. And better to “strenght up” this simple base, that topping with additional stuff. Light deficiencies of near all kind are not a problem, the plant is build for it and it make one of the most efficient plant on earth to de-pollute soil.
-
all kind of boosters used to “top” the base are a no-no.
-
the only complex nute you can give without any swing in your seeds averages is a pure amino-acid complement, and only during the week after the pollination ^^ It give an idea how much it’s more hot that it look.
-
hormons : in general i dodge all lines containing phytohormons (my choice), but to feed the mothers it’s a critical no-no.
-
Cal-mag and water : it’s when i’m gonna be burned in public place maybe : if you use one gallon of cal-mag per round (yeah it’s caricatural) or if your water is so filled with “limestone” that it let marks in your pot/tanks/watering tube/water pump/air pump … you can expect worries at the end of the chain and feedback that trash your rep ^^
-
an healthy seeded mother is not necessary a photogenic plant. Anyway you have to reach the senescence in general, when the plants start to look like shit and sick ^^ Normal, they sent the signal to just die.
-
watering : just water enough to maintain a good sap pressure that maintain a positive phototropism (don’t judge on leaves only, they can be heavy on some strains), look at the fan leaves stems and leaves set of secondaries. One little bit of water per day is a pain in the ass, but a sweet spot.
Limiting the hardiness of the shell on commercial release :
- just soak a day the seeds in humic acid (just after the water/peroxyde bath), and eventually if you master the dosages, equally dosed with fulvic acid. Don’t use this last if you know that the line is prone to herm, except if you want faster screening of course ^^