Here’s a little something from high times.
A common misconception of marijuana cultivation, especially among first-time growers, is that harvest time is like gym class in grade school—it’s still a class you have to go to but it requires less thought and more fun than an actual science class. Unfortunately, underestimating the final...
hightimes.com
When the relative humidity in the garden is low, your resin production will increase. This is a natural response cannabis has to dry air, an attempt to protect itself from hot, dry conditions. Marijuana resin actually has one of the highest UV-resistance ratings in the plant kingdom. The resin reflects light, preventing the buds from getting sunburn. (This is also why it’s so easy for helicopters to spot marijuana from the sky; it glows when seen through UV-sensitive equipment.)
Lowering the humidity in the room on that last night before harvest morning will ensure increased resin production, without having to let the medium go bone-dry first. Additionally, some growers like to subject their gardens to prolonged dark periods of up to 24 hours just before cutting, claiming they notice spikes in resin production. This is all right as the low humidity will cut down on light uptake anyway, plus it helps to make sure liquid foods within the plants drain down to the root zone.