BinaryAluminium
Member
Hi everyone. My question is: Can high temperatures prevent plants from sexing despite a 12/12 photo-period?
Here's my setup:
Lights: 1 250w HPS (in a cooltube,) 2 100w 2700k CFLs
Ventilation: 1 250 CFM (or so the manufacturer claims, I suspect it is much closer to 100 CFM) inline exhaust fan
Grow area: 2 feet x 2 feet x 5 feet (width, length, height) for a total of 20 cubic feet
Plants: 1 Indica (~2.5 feet tall), 2 Sativas (~4 feet tall)
The indica is in soil, an approved (at least according to someone on the internet) formula of peat moss, perlite and vermiculite. Both satvias are in a DWC hydroponic set up.
Grow timeline:
T-3 months, indica sprouted, under many 6500k CFLs for a few weeks
T-2 months, sativas sprouted, everything now under many 6500k CFLs and a 250w MH
T-1.5 months, the indica got severely stressed and lost many leaves due to lack of watering over a vacation, it came back very strong over the next two weeks.
T-2.5 weeks, switched to 12/12 photo-period (1 250w HPS, 2 100w 2700k CFLs) and vegging->flowering nutrients (equal parts micro, grow, bloom.) The indica has alternate branching happening now, the sativas do not yet.
T-1.5 weeks, the sativas have started alternate branching.
T-1 week, 48-hour dark period (I read online this might make the plants catch on that they should sex and start with flowering.) This didn't seem to accomplish anything.
T-5 days, switched to flowering nutrients (2, 1, 3; micro, grow, bloom; respectively)
T-0, Still no definite signs of sex. There is a small ball from which (I imagine) pistils may sprout or more balls my grow from at many nodes on the indica. There are a few nodes on the sativas where I could say the same. Nevertheless, I cannot find a pistil or anything resembling male cannabis sex organs either.
So that's the timeline. At about 5 days into flowering I fixed a couple of tiny light leaks. The amount of light leaking in was much less than moonlight and it was difficult to see one's hand in front of one's face even before fixing these leaks. Since then it is absolutely and entirely pitch black within the grow area when the lights are off.
Temperatures.
It has been very hot where I live and I do not have air conditioning. The daytime temperatures have been around 90-95f and night time about 80-85f. I'm not very sure on how to measure grow box temperatures, I've heard to measure from all, bottom, middle, top and covered from the light or uncovered. So here's some general information:
When lights are on:
Temperature near the bottom, no cover on the thermometer aside from the (very dense, at this level) canopy:
80f (this is consistent, the intake air is consistently cool)
Near the bottom, covered:
80f, still
Temperature near the middle, no cover aside from the (light) canopy:
95-100f
Middle, covered:
90-95f
Temperature near the top, no cover:
100-105f
When the lights are off, the temperatures away from the bottom quickly approach the ambient air temperature. The bottom cools more, but doesn't get below 70f.
No parts of the plants show any signs of heat stress (no leaf curling or browned edges anywhere.) As a matter of fact, all of the plants seem to be entirely healthy showing no signs of any problems. They are growing incredibly fast, as though still in the "stretch" period and I've been forced to bend the stems of the sativas to prevent them from growing above the light. The stems are still very pliable. They are going through water at a prodigious rate.
In summary:
- No light leaks
- Very high temperatures
- No signs of heat stress
- 2.5 weeks (18 days) into flowering (12/12 photo-period)
- No definite signs of sex on any plant
Are the high temperatures preventing my plants from sexing? If not, what might be?
Oh, and my apologies for not having any pictures (no digital camera.) The plants really do look completely healthy through. There's not much to see except for some plants that look to be vegging and very happy about it.
Here's my setup:
Lights: 1 250w HPS (in a cooltube,) 2 100w 2700k CFLs
Ventilation: 1 250 CFM (or so the manufacturer claims, I suspect it is much closer to 100 CFM) inline exhaust fan
Grow area: 2 feet x 2 feet x 5 feet (width, length, height) for a total of 20 cubic feet
Plants: 1 Indica (~2.5 feet tall), 2 Sativas (~4 feet tall)
The indica is in soil, an approved (at least according to someone on the internet) formula of peat moss, perlite and vermiculite. Both satvias are in a DWC hydroponic set up.
Grow timeline:
T-3 months, indica sprouted, under many 6500k CFLs for a few weeks
T-2 months, sativas sprouted, everything now under many 6500k CFLs and a 250w MH
T-1.5 months, the indica got severely stressed and lost many leaves due to lack of watering over a vacation, it came back very strong over the next two weeks.
T-2.5 weeks, switched to 12/12 photo-period (1 250w HPS, 2 100w 2700k CFLs) and vegging->flowering nutrients (equal parts micro, grow, bloom.) The indica has alternate branching happening now, the sativas do not yet.
T-1.5 weeks, the sativas have started alternate branching.
T-1 week, 48-hour dark period (I read online this might make the plants catch on that they should sex and start with flowering.) This didn't seem to accomplish anything.
T-5 days, switched to flowering nutrients (2, 1, 3; micro, grow, bloom; respectively)
T-0, Still no definite signs of sex. There is a small ball from which (I imagine) pistils may sprout or more balls my grow from at many nodes on the indica. There are a few nodes on the sativas where I could say the same. Nevertheless, I cannot find a pistil or anything resembling male cannabis sex organs either.
So that's the timeline. At about 5 days into flowering I fixed a couple of tiny light leaks. The amount of light leaking in was much less than moonlight and it was difficult to see one's hand in front of one's face even before fixing these leaks. Since then it is absolutely and entirely pitch black within the grow area when the lights are off.
Temperatures.
It has been very hot where I live and I do not have air conditioning. The daytime temperatures have been around 90-95f and night time about 80-85f. I'm not very sure on how to measure grow box temperatures, I've heard to measure from all, bottom, middle, top and covered from the light or uncovered. So here's some general information:
When lights are on:
Temperature near the bottom, no cover on the thermometer aside from the (very dense, at this level) canopy:
80f (this is consistent, the intake air is consistently cool)
Near the bottom, covered:
80f, still
Temperature near the middle, no cover aside from the (light) canopy:
95-100f
Middle, covered:
90-95f
Temperature near the top, no cover:
100-105f
When the lights are off, the temperatures away from the bottom quickly approach the ambient air temperature. The bottom cools more, but doesn't get below 70f.
No parts of the plants show any signs of heat stress (no leaf curling or browned edges anywhere.) As a matter of fact, all of the plants seem to be entirely healthy showing no signs of any problems. They are growing incredibly fast, as though still in the "stretch" period and I've been forced to bend the stems of the sativas to prevent them from growing above the light. The stems are still very pliable. They are going through water at a prodigious rate.
In summary:
- No light leaks
- Very high temperatures
- No signs of heat stress
- 2.5 weeks (18 days) into flowering (12/12 photo-period)
- No definite signs of sex on any plant
Are the high temperatures preventing my plants from sexing? If not, what might be?
Oh, and my apologies for not having any pictures (no digital camera.) The plants really do look completely healthy through. There's not much to see except for some plants that look to be vegging and very happy about it.
