I read your article, Ed's Swiss trip (CC#20, October 1999), about how your friend extracted finger hash by rubbing the leaves for their resins prior to harvest. How soon after a plant's photoperiod is flipped can you do this? Does this have any effect on the quality of yield once the plant is harvested?
Shawn,
British Columbia

The plant's production of glands containing cannabinoids increases substantially about halfway through the flowering cycle. Rubbing the leaves probably injures them a little bit, but when it is done gently, they seem to recover well. In at least some varieties, the glands that have been removed seem to grow back so the same leaves can be rubbed again later in flowering.

I don't know if rubbing the plants affects the yield of buds. It might, because the leaf tissue is wounded by the rubbing and must take time to repair itself. However, this might also stimulate growth. In studies of tomatoes it was found that agitating the plants produced more vigorous vines.

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