Here’s an answer from dubi at ace seeds about a very similar question. I asked him a while back about strains that hold higher percentages of males as it was the only way my theory could work is if you found the polar opposite to the very high female ratios and I figured he’d have had alot of exposure to many many strains done in larger quantities. Again from me it’s just a personal theory and I have no proof.
Hi,
Yes, i think i commented previously the growing variables that affect female/male ratios in regular seeds. When the regular seeds are reaching their sexual maturity:
- Excessive nitrogen produces more males
- High temps produce more males, cooler temps more females
- Plants get rootbound more males, plants have enough root space more females.
- Crowded gardens produce more males, seedlings grown with enough space between them produce more females
- Outdoor seeds planted late in summer produce more males, earlier in spring more females
- Long photoperiods produce more males, shorter photoperiods more females
- Lack of water or nutrients during sexing produce more males, the right amounts of water and nutrients more females
- Plants abused during seedlings stage with stress (excessive pruning and other stress) tend to become male more frequently, properly attended seedlings produce a higher female ratio.
- Lack of proper ventilation in indoor rooms produce a higher male ratio, well ventilated indoor rooms produce more females.
- Yellowish HPS light spectrum produces more males, whiter-bluish light spectrum more females.
Usually tropical pure sativa landraces like Thais, Soth Indians, Colombians, etc … produce a very high female ratio, although sexually firm males can be harder to find.
Most of our sativa strains (standard/regular releases) of tropical origin produce a high female ratio. Hope it helps.