Here is a direct quote from the
Dutch Passion website:
From literature and our own findings it appears that the growth of a male or female plant from seed, except for the predisposition in the gender chromosomes, also depends on various environmental factors. The environmental factors that influence gender are:
1 a higher nitrogen concentration will give more females.
2 a higher potassium concentration will give more males.
3 a higher humidity will give more females.
4 a lower temperature will give more females.
5 more blue light will give more females.
6 Fewer hours of light will give more females. It is important to start these changes at the three-pairs-of-leaves stage and continue for two or three weeks, before reverting to standard conditions.
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