New Grower Preharvest Tips

[GCase]

This is an interesting thread.

Autos and lights can really get the chat a going. It is a hot topic. Opinion and anecdotal feedback is great. The science is even better.

Will go back and read all comments.

Those above are very interesting and well thought out. Thanks.

Couple of comments:

Lighting for autos is a great discussion. The origin of the breeding stock for autos is full of mystery--often called a Mexican Rudy and read one article pointing towards US lab genetics.

So, lighting gains interest. Do the autos still have residual pr and pfr hormones per flowering. Leading to many questions. And could other than stimulate flowering in photos--could--sundown (lights off) actually be healthy for a plant to expend stored energy collected thru the day and to ease both respiration and transpiration.

I play the middle at 20/4. Or thereabouts.

Dark period before harvest.

Take a look at this--from Dinafems description of a WW suggestion: "Production may be lower than for other strains but this is compensated by its resin coated flowers, offering very good strength and a mixed physical and mental medicinal effect, which is truly pleasurable. The flowering period lasts around 60 days indoors, which is necessary for maximum resin production; it is advisable to leave them in complete darkness for the last 5 days, to increase resin production as much as possible."

The dark period worked well for me last grow. Just a few days. No THC and CBD are genetic functions and nothing beyond a perfect environment will help. What the dark period may do is---Allow the terpines/flavanoids to mature/age without both their deterioration and THC degrading which occurs with lights on. If one looks at terpine charts--all terpines are highest just before lights go back on. Meaning terpine evaporation is evident after plant cools down--but, is greater with lights on.

Here is what it did for me:

1. Could pick fan leaves and non essential leaves off before going in empty tent.

2. Use a couple of fans indirect.

3. Buds seem to draw resources around the bud leaves and begin evaporating at same time. As a consequence, trimming is a breeze after stems are cut and then dried/cured.

4. In a dry environment using a dark period--may--as is my case--help get a few more days of drying and a better final product (aroma and burning/vaping).

 

[Son of Hobbes]

This is an interesting thread.

Autos and lights can really get the chat a going. It is a hot topic. Opinion and anecdotal feedback is great. The science is even better.

Will go back and read all comments.

Those above are very interesting and well thought out. Thanks.

Couple of comments:

Lighting for autos is a great discussion. The origin of the breeding stock for autos is full of mystery--often called a Mexican Rudy and read one article pointing towards US lab genetics.

So, lighting gains interest. Do the autos still have residual pr and pfr hormones per flowering. Leading to many questions. And could other than stimulate flowering in photos--could--sundown (lights off) actually be healthy for a plant to expend stored energy collected thru the day and to ease both respiration and transpiration.

I play the middle at 20/4. Or thereabouts.

Dark period before harvest.

Take a look at this--from Dinafems description of a WW suggestion: "Production may be lower than for other strains but this is compensated by its resin coated flowers, offering very good strength and a mixed physical and mental medicinal effect, which is truly pleasurable. The flowering period lasts around 60 days indoors, which is necessary for maximum resin production; it is advisable to leave them in complete darkness for the last 5 days, to increase resin production as much as possible."

The dark period worked well for me last grow. Just a few days. No THC and CBD are genetic functions and nothing beyond a perfect environment will help. What the dark period may do is---Allow the terpines/flavanoids to mature/age without both their deterioration and THC degrading which occurs with lights on. If one looks at terpine charts--all terpines are highest just before lights go back on. Meaning terpine evaporation is evident after plant cools down--but, is greater with lights on.

Here is what it did for me:

1. Could pick fan leaves and non essential leaves off before going in empty tent.

2. Use a couple of fans indirect.

3. Buds seem to draw resources around the bud leaves and begin evaporating at same time. As a consequence, trimming is a breeze after stems are cut and then dried/cured.

4. In a dry environment using a dark period--may--as is my case--help get a few more days of drying and a better final product (aroma and burning/vaping).

No THC and CBD are genetic functions and nothing beyond a perfect environment will help. What the dark period may do is---Allow the terpines/flavanoids to mature/age without both their deterioration and THC degrading which occurs with lights on. If one looks at terpine charts--all terpines are highest just before lights go back on. Meaning terpine evaporation is evident after plant cools down--but, is greater with lights on.

I would agree with that observation; here's some food for thought based on my own research (an old guide I was working on; needs revision and clarification but is based on a lot of university findings

Marijuana plants, as well as many other plants, produce organic compounds called terpenes. Terpenes are a major component of resin, often very strong smelling, and sometimes act as a protective function for the plant.

When terpenes are modified through chemical processes (oxidation or reduction) they become terpenoids. Plant terpenoids are primarily sought after for their fragrant aromatic qualities, especially when it comes to essential oils (terpenes and terpenoids are a large basis of aroma therapy.)

It is thought to be believed that the amount of terpenes present in marijuana resin affects the potency of the THC in the resin. Since terpenes are secreted by the marijuana plant's glandular trichomes; it is important to try to increase trichome production through good gardening practices (as you will find in other guides on this site.)

Terpenes are also highly volatile and evaporate quickly. The marijuana plant constantly produces terpenes, but heat and light also destroys them. This is why it's important to keep temperatures at a constant (within range for the plant) in your growing space. This is also why it is advised to harvest your plants early in the morning (or before lights on.)

The curing and drying process can also affect how well terpenes are preserved. This is why you can have some dank smelling herbs while growing; then botch (accidentally of course) your curing/drying process and have herb that doesn't have much of a smell (or a weird smell.) Heat and excessive or rapid evaporation can cause terpene reduction in your buds. This is why slow drying/curing is often preferred over some faster conventional methods.

Terpenes can vary greatly depending on their environment and climate. The same plants grown in one substrate may produce terpenes different than if they were grown in another type of substrate. The same goes with fertilizers; one type of fertilizer product line may cause different terpene production than another fertilizer line.

There are over 120 different kinds of terpenes that can be produced by marijuana in small trace amounts or large quantities.

Need links to back up some of the claims of course so take it with a grain of salt; but is based on my findings of research and observation.

Here's a pretty cool run-down of terpene measurement in a lab setting:

Medical Cannabis Terpene Measurement
using the SRI 8610C FID GC

 

[Milky]

There might be some truth to this harvest in the dark thing cause I remember that DMT should be harvested at noon as the levels are much higher.

 

[unixhelp]

I always assumed to get the best results indoors you have to mimic the outdoors as best you can but thats just an opinion from a grower with less than a year growing. I can't remember the last time it was dark for 3 straight days...I would think it would make more sense to keep the same light schedule and just use a few bloom cfl lights around the lower part to the plant to mimic the autumn sun? make sense or am i full of bull hinkey?

 

[Wait what?]

Plants get darkness in nature, I give it to them I my closet. They he look better when I do, just my experience

 

[Anthropolis]

Since I don't have a good working method of 72 hours of darkness in my tent, I'm building a wooden box next to the tent, just big enough for a plant or two, with the tent intake airflow going through it with a duct booster fan pulling air through So the plan is, to have a 4" hose going from a window as it is now but to the bottom side of the box, and then a 4" duct on the top side of the box, then to some ducting then through the duct booster fan, then into the tent. I have a monster 6" fan and filter combo inside the tent blowing air out through a 6" ducting to a different window and pushed out.

So far, I did the 72 hours with one plant, but just stuck it in a cardboard box, I was being lazy and didn't rig up a fan, and found a tiny bit of mold had grown on a dead leaf stem that I missed removing. Fortunately it didn't get to any bud, and I chopped the plant immediately. Now I know that it absolutely requires airflow, and of course complete darkness. I could build a box inside the tent, but I got a tiny tent (2'x4'x5') and any fan holes would be letting in tons of light. So, I'm building a box in the intake line that way it'll get darkness, airflow, and it's stink will just go into the tent and be handled by the carbon filter with the stink of the other plants

I'll let you guys know how it works out lol

 

[unixhelp]

Since I don't have a good working method of 72 hours of darkness in my tent, I'm building a wooden box next to the tent, just big enough for a plant or two, with the tent intake airflow going through it with a duct booster fan pulling air through So the plan is, to have a 4" hose going from a window as it is now but to the bottom side of the box, and then a 4" duct on the top side of the box, then to some ducting then through the duct booster fan, then into the tent. I have a monster 6" fan and filter combo inside the tent blowing air out through a 6" ducting to a different window and pushed out.

So far, I did the 72 hours with one plant, but just stuck it in a cardboard box, I was being lazy and didn't rig up a fan, and found a tiny bit of mold had grown on a dead leaf stem that I missed removing. Fortunately it didn't get to any bud, and I chopped the plant immediately. Now I know that it absolutely requires airflow, and of course complete darkness. I could build a box inside the tent, but I got a tiny tent (2'x4'x5') and any fan holes would be letting in tons of light. So, I'm building a box in the intake line that way it'll get darkness, airflow, and it's stink will just go into the tent and be handled by the carbon filter with the stink of the other plants

I'll let you guys know how it works out lol

Great idea putting a drying box on the intake...keep an eye on it though, a good dry breeze will dry out your buds real fast

 

[GCase]

Someday we will find some scientific info. to verify our understanding of a dark period prior to harvest. It is possible that the overlying purpose is to preserve THC from deterioration and allow some continued ripening.

We know this--after ripening THC deteriorates with additional light. Canna is a fall ripening plant. So days are shorter and THC deterioration is lessened by lack of direct sun light.

Indoor growing is compressing many months into a few. Tricking the plant first with 24 hours or up to at least over 16 hours with photos and almost any light intensive schedule for auto.

So in both cases, indoors, lightening is consistent in intensity (spectrum never changes like outdoors) and non-natural.

The pr and pfr interchange may also be at work.

In my case--dry climate--a 48 period of darkness does help. Longer dry/cure--the 48 hours is like a pre-cure/dry. Two extra days are beneficial when drying/curing in very low RO or in presence of more heat than required. Manicuring is a breeze--I did mention this in an earlier comment.

When dark--already ripe buds do not deteriorate--for the rate is fast once ripe. Plant is not busy with transpiration/respiration and can use all of its stored energy. Lastly, buds become more sticky/juicy/dank.

Yet--this method probably is of no use in climates/environments that are high RH and/or lower temps.

Who knows--for sure. Could be the benefits are just in my imagination.

Playing around with harvesting techniques can be fun. For example: Going to dry two plants the old way by drying in the open for at least four weeks then making real traditional screened hash. Dark period won't matter in this situation.

Here is just a basic HT harvest overview. es it is HT magazine and some don't care for their advise.

http://www.hightimes.com/read/key-points-harvest-time

 

[kicks]

Plants get darkness in nature, I give it to them I my closet. They he look better when I do, just my experience

Just make sure its dark enough that when you hold your thumb in front of you, you wont be able to see it. That's how you know its dark enough "General Rule"