so after 11 years, whats the conscious? To Trim or not to Trim?
I don't think there is a full consensus still. There seem to be as many for defoliation as there are against though. Perhaps because lollipopping seems to be a productive technique? Perhaps it is because different growers have different anecdotal evidence.
I have just burned the living daylights out of almost all the fan-leaves on my last crop with lights too close to the top (they're dwarf plants anyway, most of the plant is at the top) and with a nutrient / pH balancing cockup in soil.
The plants stalled while I was normalizing the problem and now they are just a few buds and sugar leaves. BUT, they are maturing and they are growing, slowly but surely.
I'd say - lollipopping apart - it is better to leave fan leaves on if you can. Trimming leaves that you can't tuck out of the way can help light and air to reach the lower and central parts of a plant, but I've not seen benefits to removing fan leaves wholesale.
To be honest, I haven't seen enough benefit to tucking fan leaves to prove the theory, but it would seem to make sense. Reading around the topic, from what I understand anyway, sugars produced by leaves are shared among the plant to an extent, but it seems that sugars are mainly utilized close to the site of production.
So, leaving fan leaves on near buds would appear to be the best way for those buds to access the most energy for growth. That said, large leaves shading otherwise promising buds could cause less growth overall as they feed local buds, but starve the buds below of light.
I guess the answer is that removing some leaves will help in some circumstances and hinder in others. You have to work out where the most gain lies. Like, a big fan leaf shading a whole branch vertically will mean less energy for a whole branch, whereas removing it (providing there are other fan-leaves on the same tranche) would have marginal effect on the local bud's energy levels.
Having seen the result of nearly total fan leaf defoliation this time (albeit linked to heat and nutrient burn / lockout), I won't be putting a totalitarian regime into place myself. Each leaf should be judged on its own merit imho and the plants I have grown without removing leaves for the sake of it have fared better than those where leaves were removed in greater numbers - for experimental purposes or by accident.