I was reading the thread about 20/4 vs 18/6 and people talked about stem elongation...I wanted to post about a technique that non-cannabis greenhouse growers use to keep their plants squatty. It's called negative DIF.
DIF stands for the difference between day and night temps. Apparently some plants elongate their stems in relation to that difference. The bigger the difference, the more the plants stretch. So someone had the idea to make the night temps actually higher than the daytime temps, thus the term "negative DIF." It turns out that helped to produce very squatty plants with tight internodes.
One caveat is that the effect seemed to evaporate when the natural day lengths got longer in the spring. Therefore it might not work with autos growing on a 20/4 or 18/6 cycle.
I'd love to see someone try it, however, with photos on 12/12. I can picture a setup with two grow areas on alternate schedules running HID's and venting the heat from the lights into the other area.
Another technique is called a DIP. Since plants do most of their stretching in the early morning you can hit them with a burst of cold air for about an hour right when the lights come on to control stretch. Again, I have no idea if this would work with cannabis.
DIF stands for the difference between day and night temps. Apparently some plants elongate their stems in relation to that difference. The bigger the difference, the more the plants stretch. So someone had the idea to make the night temps actually higher than the daytime temps, thus the term "negative DIF." It turns out that helped to produce very squatty plants with tight internodes.
One caveat is that the effect seemed to evaporate when the natural day lengths got longer in the spring. Therefore it might not work with autos growing on a 20/4 or 18/6 cycle.
I'd love to see someone try it, however, with photos on 12/12. I can picture a setup with two grow areas on alternate schedules running HID's and venting the heat from the lights into the other area.
Another technique is called a DIP. Since plants do most of their stretching in the early morning you can hit them with a burst of cold air for about an hour right when the lights come on to control stretch. Again, I have no idea if this would work with cannabis.
