cdgmoney250
Well-Known Member
I definitely think you are right.Far red light is associated with stretch, but a 3:1 ratio is still 3x as much red:far red as the sun which is around 1.2:1 ratio. Plants use Far Red for positioning to not only sense other plants proximity but also under canopy where shade avoidance syndrome can occur. You probably didn't see stretch because it wasn't enough far red... In a previous grow I used the Budmaster Emerson for 1 hour during mid day (80w of far red vs about 500w of mixed spectrum) and saw a huge increase in stretch, so I stopped using the far red during the daylight period..
Using it on this last grow only for 15 minutes did not increase my stretch, so its probably a matter of total amount of far red light during a day period, similar to how we judge plant lighting like DLI... broken down into PPFD per hour.
There definitely is proven research though that shows that the lower the ratio of Red to Far Red, the more stretch will result, so maybe you have a good amount of far red, but not to much where it influences the shade avoidance effect.
I've done a fair bit of research into the Emerson Effect and the photosystems I & II. I based the ratio of light I chose off the Mccree Action Spectrum as opposed to the solar spectrum. This is why I chose a 3:1 Red:FR ratio.
I don't care about extra stretch and I'm glad I didn't get any. My goal with adding Red/FR was to try to elicit the Emerson Effect and increase photosynthetic efficiency. Not to elicit a shade avoidance response. I was just surprised not to see any stretch above and beyond what I normally see. I just figured I would have noticed something, the way everybody talks about seeing plants stretch 2-3x what they are used to by adding a few watts of 730nm per day.