Co2 during flowering

[SinSemillaWhisperer420]

Roast away

 

[Hollatchaboy]

The ground freezes in the winter. I’m growing indica and don’t live near the equator

Frozen ground and permafrost are different.

 

[SinSemillaWhisperer420]

Lol I’m a newbie looking to learn and share what I learned. This is my 3rd grow. Thanks for the tips. You get the best advice when everyone’s is a critic. Unfortunately, you have to bea douche urself to get the most critical advice. By the way we don’t know for sure if bro science is just not legitimate yet because of lack of controlled documented studies (due to the government prohibiting it for so long).

 

[SinSemillaWhisperer420]

Check ice equals bro science equals we don’t know but it will turn them purple.

 

[SinSemillaWhisperer420]

I sincerely appreciate all of ur guy’s attention to detail and time. But I think I got down the notes I needed.

 

[Herb & Suds]

I sincerely appreciate all of ur guy’s attention to detail and time. But I think I got down the notes I needed.

I doubt that

 

[Hollatchaboy]

Science studies don’t lie 11 day drought stress

Who's science are you referring to?

 

[Herb & Suds]

Who's science are you referring to?

VODKA U

 

[jondamon]

Lol I’m a newbie looking to learn and share what I learned. This is my 3rd grow.

And here it is!

so you’ve been growing for about what? 1 year?

Already a master grower. ffs.

if you want to learn heres a tip.

god gave you 2 ears and 1 mouth so that you can listen twice as hard as you can talk.

 

[bk78]

Here kitty

Shrimp or cat?

 

[Herb & Suds]

Shrimp or cat?

View attachment 5016062

Perfect

 

[twentyeight.threefive]

Perfect

Purrfect?

 

[Herb & Suds]

Purrfect?

Oh brother

 

[Milky Weed]

If I had any input on the Mylar, plants generally like diffuse light more than direct beam, and I believe Mylar would promote more direct beam via mirroring (if you get it flat) vs diffusion of light by flat white.

this is likely a small difference and mainly comes down to preference.

 

[Herb & Suds]

If I had any input on the Mylar, plants generally like diffuse light more than direct beam, and I believe Mylar would promote more direct beam via mirroring (if you get it flat) vs diffusion of light by flat white.

this is likely a small difference and mainly comes down to preference.

“I believe” is bro science

 

[SinSemillaWhisperer420]

3 Tips for Controlled Drought Stress
Departments - Upfront | Quick Tips
Limit water to maximize cannabinoid and terpene levels in cannabis production.
SUBSCRIBE
May 26, 2021
Dr. Deron Caplan, Ph.D.

Figure 1. Location for leaf angle measurement to indicate degree of wilting in cannabis.
Severe drought lowers yields and kills crops, but, in moderation, drought can stimulate secondary metabolite production. Slight and infrequent drought stress combined with high solar radiation is recognized to increase essential oils in herbs and spices in places such as the Mediterranean. Fortunately, cannabis growers can also use drought to their advantage to increase the secondary metabolite content, or cannabinoids and terpenes, of their crops.
Researchers at the University of Guelph (U of G)found that a single controlled application of drought stress increased the concentration of tetrahydrocannabinol acid (THCA) and cannabidiolic acid (CBDA) by 12% and 13%, respectively, compared to a non-stressed control. Further, yield per unit growing area of THCA, CBDA, THC and CBD increased 43%, 47%, 50% and 67%, respectively.
Applying controlled drought stress may be difficult in some cultivation systems, but for those interested in experimenting (carefully), here are some tips.
Tip 1: Go slow and watch for wilting.
In the U of G study, drought stress was applied by allowing the container-grown cannabis plants to dry slowly under standard conditions. As water became limiting (around the 11-day mark), the fan leaves began to wilt and the plants were rewatered. Wilting was defined as a 50% increase in leaf angle from their normal state and measured using a handheld protractor (Fig 1).
Note that the wilting response to drought varies by species, and only one cultivar was used in the study. Other cultivars may wilt differently, making it important to watch your plants closely. Other drought stress indicators such as growing media moisture content may be better suited for some cultivars.

Figure 2. Visual effects of drought stress on Cannabis sativa L. ‘NC:Med (Nebula)’
Photos by Deron Caplan
Tip 2: Apply drought stress during mid-to-late flowering.
Drought stress timing is essential to minimize yield losses and maximize the concentration of secondary metabolites. If drought is applied while the plants are growing vegetatively, you can expect a drop in yield. In the U of G study, drought was applied at week 7 in flower when vegetative growth was mostly complete.
Cannabinoids accumulate mostly during the flowering stage, but the timing of cannabinoid concentration varies by cultivar. It is best to collect cannabinoid content data throughout the crop to inform when to apply the stress, but this can be cost prohibitive for some growers. In most cases, a good place to start is two to three weeks before harvest and iterate from there.
Tip 3: Start slow, and don’t overdo it.
A host of factors can influence water use in plants. For example, high heat, low humidity and high airflow can increase water usage. Additionally, a low growing media volume can decrease water availability. Both increased water usage and reduced availability can expedite drought stress symptoms.
In the U of G study, wilting occurred after 11 days without water. The drought stress was gradual, allowing the plants to acclimate. Keep this time frame in mind when applying drought stress in your cultivation system—you may need to adjust environmental conditions, the growing media, or the pot size to get comparable results.
Dr. Deron Caplan, PhD, is the Director of R&D at Flowr in Kelowna, B.C.
References
1. Kleinwächter, M. & Selmar, D. New insights explain that drought stress enhances the quality of spice and medicinal plants: Potential applications. Agronomy for Sustainable Development. 35, 121–131 (2015).
2. Caplan, D., Dixon, M. & Zheng, Y. Increasing Inflorescence Dry Weight and Cannabinoid Content in Medical Cannabis Using Controlled Drought Stress. HortScience. 54, 964–969 (2019).
3. Xu, Z., Zhou, G. & Shimizu, H. Plant responses to drought and rewatering. Plant Signal Behavior. 5, 649–54 (2010).

 

[Boatguy]

Tip 1: Go slow and watch for wilting.

Tip 3: Start slow, and don’t overdo it.

 

[SinSemillaWhisperer420]

Who's science are you referring to?

3 Tips for Controlled Drought Stress
Departments - Upfront | Quick Tips
Limit water to maximize cannabinoid and terpene levels in cannabis production.
SUBSCRIBE
May 26, 2021
Dr. Deron Caplan, Ph.D.

Figure 1. Location for leaf angle measurement to indicate degree of wilting in cannabis.
Severe drought lowers yields and kills crops, but, in moderation, drought can stimulate secondary metabolite production. Slight and infrequent drought stress combined with high solar radiation is recognized to increase essential oils in herbs and spices in places such as the Mediterranean. Fortunately, cannabis growers can also use drought to their advantage to increase the secondary metabolite content, or cannabinoids and terpenes, of their crops.
Researchers at the University of Guelph (U of G)found that a single controlled application of drought stress increased the concentration of tetrahydrocannabinol acid (THCA) and cannabidiolic acid (CBDA) by 12% and 13%, respectively, compared to a non-stressed control. Further, yield per unit growing area of THCA, CBDA, THC and CBD increased 43%, 47%, 50% and 67%, respectively.
Applying controlled drought stress may be difficult in some cultivation systems, but for those interested in experimenting (carefully), here are some tips.
Tip 1: Go slow and watch for wilting.
In the U of G study, drought stress was applied by allowing the container-grown cannabis plants to dry slowly under standard conditions. As water became limiting (around the 11-day mark), the fan leaves began to wilt and the plants were rewatered. Wilting was defined as a 50% increase in leaf angle from their normal state and measured using a handheld protractor (Fig 1).
Note that the wilting response to drought varies by species, and only one cultivar was used in the study. Other cultivars may wilt differently, making it important to watch your plants closely. Other drought stress indicators such as growing media moisture content may be better suited for some cultivars.

Figure 2. Visual effects of drought stress on Cannabis sativa L. ‘NC:Med (Nebula)’
Photos by Deron Caplan
Tip 2: Apply drought stress during mid-to-late flowering.
Drought stress timing is essential to minimize yield losses and maximize the concentration of secondary metabolites. If drought is applied while the plants are growing vegetatively, you can expect a drop in yield. In the U of G study, drought was applied at week 7 in flower when vegetative growth was mostly complete.
Cannabinoids accumulate mostly during the flowering stage, but the timing of cannabinoid concentration varies by cultivar. It is best to collect cannabinoid content data throughout the crop to inform when to apply the stress, but this can be cost prohibitive for some growers. In most cases, a good place to start is two to three weeks before harvest and iterate from there.
Tip 3: Start slow, and don’t overdo it.
A host of factors can influence water use in plants. For example, high heat, low humidity and high airflow can increase water usage. Additionally, a low growing media volume can decrease water availability. Both increased water usage and reduced availability can expedite drought stress symptoms.
In the U of G study, wilting occurred after 11 days without water. The drought stress was gradual, allowing the plants to acclimate. Keep this time frame in mind when applying drought stress in your cultivation system—you may need to adjust environmental conditions, the growing media, or the pot size to get comparable results.
Dr. Deron Caplan, PhD, is the Director of R&D at Flowr in Kelowna, B.C.
References
1. Kleinwächter, M. & Selmar, D. New insights explain that drought stress enhances the quality of spice and medicinal plants: Potential applications. Agronomy for Sustainable Development. 35, 121–131 (2015).
2. Caplan, D., Dixon, M. & Zheng, Y. Increasing Inflorescence Dry Weight and Cannabinoid Content in Medical Cannabis Using Controlled Drought Stress. HortScience. 54, 964–969 (2019).
3. Xu, Z., Zhou, G. & Shimizu, H. Plant responses to drought and rewatering. Plant Signal Behavior. 5, 649–54 (2010).

 

[Flowki]

Science studies don’t lie 11 day drought stress

In this age of academic pay walls and/or vested interests, the conservative estimate is that 90% of published studies are full of shit, peer reviews only validate the method (essentially), it is independent retesting that validates the findings, but that isn't done often enough. Despite any accidental errors or genuine false positives, there are multiple ways to out right deliberately fuck with data. Look up P hacking as just one example.

 

[SinSemillaWhisperer420]

In this age of academic pay walls and/or vested interests, the conservative estimate is that 90% of published studies are full of shit, they are not properly proof tested for accuracy, peer reviews only validate the method, only retesting can validate the findings. Despite any accidental errors or genuine false positives, there are multiple ways to out right deliberately fuck with data. Look up P hacking as just one example.

There are multiple publishers and a multitude of studies. Not just this study but sure to each there own