This will be my second attempt at using Far Red for manipulation of flowering. My first test was cut short by hardware failure but this time around will be using multiple series each with an independent driver. This should allow a portion of light to continue to work if another part fails. I will using 3 strains in this test, Greenhouse Seeds Arjan Haze #2, World of Seeds Strawberry Blue, and Dutch Passion Strawberry Cough. Nutrients and Additives GH Flora Micro GH Flora Bloom GH KoolBloom Grotek Pro Silicate HC Snow Storm Hygrozyme Lights 220W PL-L 3000k 12W LED 740nm Cycle is 10 hours on 2 hours off on main light. The Far Reds trigger 5 mins after lights out for 5 min on then 5min off 3 times. Day 1 Flower (2 synthetic days) Canopy Approx 19" high, already showing some stretch. This thread is what got me started down this path, Loki7 is the one that first introduced the idea of using Far Red Light in order to stimulate the phytochrome to induce flowering. http://forum.grasscity.com/indoor-grow-journals/708183-lokis-side-side-730nm-flowering-experiment.html Will explain process in more detail in follow on thread/threads.
This is what I used for my first attempt at Far Red Manipulation. http://forum.grasscity.com/attachme...e-side-730nm-flowering-experiment-led1-1-.jpg http://forum.grasscity.com/attachme...side-side-730nm-flowering-experiment-led2.jpg This is my second version http://forum.grasscity.com/attachme...-pl-l-lights-4-cubes-220w-each-pix-frv2-4.jpg http://forum.grasscity.com/attachme...-pl-l-lights-4-cubes-220w-each-pix-frv2-7.jpg
Day 3 (Synthetic day 6) These are from last night just getting them up today. Can see the stretch happening looking into so blue manipulation in next experiment to counter some of that.
I have started this thread without much introduction into the methods I am testing. If those who are looking at it have not read Loki7 thread I highly recommend doing so. The basic principle of what I am attempting to do is to use a Far Red spectrum of light to trigger flowering. Cannabis is classified as a short day plant meaning that in order for it to enter its fruiting/flowering cycle the days have to decreasing hours of light and inversely long periods of darkness. Being that plant can not actually tell time there is a trigger for, plants uses various pigments in order to be able to sense there environment. The one that is of particular interest is known as the phytochrome. The phytochrome is kind of like a flip flop. When is is exposed to a high level of red light it changes in receptors for far red, then when exposed the far red it changes back to red receptors. Sunlight has a very high concentration of red light and so it changes most the phytochrome to far red receptors through out the day. Once night time comes the far red receptor slowly switch back to red over the dark period. This would be why periods of light can interrupt flowering, enough light will start to switch the receptors back over and make the night seem shorter. What we want is the opposite effect make shorter nights seem longer. So at the beginning of the dark period an exposure of far red light helps to switch the far red receptors into red receptors in a much smaller period of time. By doings so the potentional of tricking plants into believing more days have past shorting flower time, or the ability to get more light hours on a flowering plant for better growth. Based on what you see with auto flower plants and the ability to have longer light periods usually is a combination of both. They tend to be short cycle plants that will yield proportional to how much light you feed them. I believe that by manipulation of the phytochrome we will be able to have growth patterns simular to an autoflower but instead use better photoperiod genetics. My initial testing is done on the idea that I will try to squeeze 2 days into one by using a 10 hour light period with a 2 hour dark period 2 times a day. To help make the plant change the receptors over to red, the use of far red (735nm) in a couple short bursts at the beginning of the dark period. I am on the 12th day of this light schedule I can see the signs that it is close to flowering but it is not switching over. The plants really start to stretch under these conditions like you see in flowering, which in my smaller area I am testing this in can become a problem. In futures runs once I work out a good cycle time I have some idea to help control stretch. So today I changed the cycle slightly moving from a 10/2 to 9/3, I will continue to use this for awhile before decreasing further. I would prefer to be using 2 12 hour periods but if day period gets to short will look into doing 18 hour periods. There is many other variable which could also play a role in this such as intensity of far red light? How long the far red period/periods should be? Would going the route of making 2 shorter days or one longer days be the better route? I lean towards shorter days to help avoid reaching a light saturation point in the plant.
I decided to train them down some because of the stretch they have been getting from the far reds. My other option would be to prune but trying to avoid that for now. Before After
Wow... is that as red IRL as it is in the pics? If it is you're probably going to get an emerson effect reaction. -Loki
The picture are not a true representation. I have a decent camera but even it has trouble getting a picture in the light. The light is a little bit darker then it looks in the picture the camera on the other hand is picking up stuff that's at the edge of our vision and washing the image out like you see with a bright light in picture. I wish I had a means to get an actual spectrum reading off the lights. I ended up pulling the Arjan Haze and put it in a different box that way I have more room to deal with plants trying out grow their area. Plus gives me a way to see if I can get 6=7oz off of 4 plants in a 2x2.
3 Days on the new cycle of 9/3 the stretch has slowed some but still has not really gone into flowering. Will continue for a few days and then look at going to 8/4. Had to do some cutting today to much branching.
Decided to switch over to 18/6. I would like to keep the hours of light up so went this route over 7/5. The exposure time is the same at start of dark period. I will not be changing that for now. I am trying to change only one variable at a time. Still getting branches shooting up. The strawberry blue is getting thick may have to cut stuff out soon. Nothing new here. Relocated my fan. Flattened back out for now
I was wondering if there might be a way to filter the red out of the far red? I think you're going to have too much red light counter acting the far red. -Loki
Well get pics up at home, but no change really. Vertical height is becoming an issue. Canopy is almost at a limit for training cutting air circulation some. Increased exsposure to 10 min 3 times.
This run is getting pulled need fresh plants they have overgrown the area and need to be re potted and given more space. Will use a much smaller plant for the next run. I use these two strains for my rolling mix and I am running out so want to get them finished to restock.
This thread was pretty funny. The OP was in the process of proving yet again that Cannabis is indeed a long night plant. 2, 3 or even 6 hours won't do, regardless of far red treatment at start of dark cycle. All the FR does is turn the Pfr to Pr immediately instead of it taking 2 hours normally. So with the 2 hour nights it was equivalent to 4 hour nights. With the FR you would still need at least 9 hours of dark.