i have started defoliating all the way through the entire grow. Much conventional wisdom on this is down the drain. My plants are growing great, more healthy and are producing more buds during the same cycle. I remove all fan leaves that have at least a 1/4" budding joint established.
To me it seems as if fan leaves do not store up the energy of the plant as commonly thought, but they actually TAKE energy away from the budding joints. In my testing, i found zero difference in the size of buds for branches with or without fanleaves, BUT, those buds covered by the fanleaves were smaller. Thus, removing them actually increased bud size as the canopy had more light.
Thus my realization is that fan leaves help to begin the budding joint, then only exist as a "castoff" for animals browsing, and to take excess toxins in. I also notice that after the budding joint is well established, fan leaves generally begin to redstem and lose vigor anyway.
Benefits:
1) more light and airflow through canopy, and more even
2) MANY more budding joints growing
3) less problems due to density(ie. less bud rot, pm, etc)
4) bigger fatter flowers as they receive more light
5) easier trimming
6) less nutrients needed
etc..
I've grown over 25yrs, and have always defoliated some. Now i do it consistently and LOVE the results.
As folks say, "Are we growing fan leaves or buds??"