Scientific Trials Show No Chemical Difference in Plants After Flushing

SUMMARY
  • Rx Green Technologies evaluated the effects of different flushing times on chemical profile, flavor, and smoking characteristics in Cannabis flower.
  • Flushing periods of 14, 10, 7 and 0 days were imposed on Cherry Diesel.
  • No differences were detected between flush treatments for yield, potency, or terpenes.
  • Analysis of mineral content of leaves indicated small changes in content of iron and zinc.
  • Taste test panelists tended to prefer flower flushed for 0 days.
INTRODUCTION
Taste and combustion qualities of Cannabis are dependent on the chemical characteristics of the flower. These chemical characteristics can be influenced by management practices during the growing cycle. For this reason, many Cannabis growers implement a flushing period where only water is fed to plants in the final days to weeks before harvest. While many cultivators attest to the effects of a flush, no scientific studies have been conducted to validate this practice. Rx Green Technologies has undertaken a first of its kind study to determine the influence of different flushing times on the chemical profile, flavor, and combustion characteristics of Cannabis flower.

MATERIALS AND METHODS
Cannabis variety Cherry Diesel (Cherry OG x Turbo Diesel) was grown at the Rx Green Technologies R&D Facility using Rx Green Technologies nutrients and Clean Coco. Grow A, Grow B and E-Plus were fed during the vegetative stage and Bloom A, Bloom B, E-Plus, and Bulk were fed during the flowering cycle. The first flushing period began 14 days before harvest. The other flushing periods were ten, seven, and zero days before harvest. Each flushing period was tested on 12 different Cherry Diesel plants divided into four different groups (replications) spread evenly across the flowering room tables. Flower and fan leaf samples were collected from each flushing treatment the first day of flush and the day before harvest to quantify concentrations of essential plant nutrients. After harvest, trial plants were cured before determining final trimmed flower weight, terpene and THC concentrations. Trim was evaluated by an extractor for THC, yield, and appearance of the extract or “wax”.
To determine smoking flavor and characteristics, samples of each flushing period were distributed to Cannabis industry experts in a blind taste test. Each participant received one sample of each flushing time without knowledge of its treatment. Participants were asked about their personal Cannabis flavor preferences before tasting. After tasting, participants were asked to rate the sample for flavor, harshness of smoke, and color of ash.
Data collected during the course of the trial were analyzed statistically to determine whether flushing times affected smoking quality, flower weight, or chemical characteristics of Cannabis. Statistical analysis of data allows us to quantify whether differences in the numbers are due to the treatments imposed or are results of the natural variations observed when growing plants.

RESULTS AND DISCUSSION
Visual differences in fan leaves between flushing times were apparent the day before harvest. Plants flushed for ten or 14 days had leaves that were more yellow, necrotic and dry than plants flushed for zero or seven days (Figure 1a-d). The color of the 14 and ten day flushed leaves indicates a greater breakdown of chlorophyll in the plant, leading to reduced greenness

Figure 1. Fan leaves collected from Cherry Diesel plants the day before harvest. Flushing times depicted are (a) 14 days, (b) 10 days, (c) 7 days, and (d) 0 days.

Yield, THC, and Terpenes
The flower weight, THC and terpene content of cured flower were determined for each flushing period. The data were analyzed statistically to determine whether the numerical differences in the data were due to the treatment. Overall, there were no significant differences between treatments for flower weight, THC or terpene content (Figure 2a-c) (P < 0.05). Flower weight per plant averaged 97.3 g and THC content averaged 21.9%. The dominant terpenes in the flower were beta-myrcene, beta-caryophyllene, and terpinolene, giving the flower an earthy and spicy smell (Figure 2c). Overall, flushing times did not impact flower weight, THC, or terpenes in Cherry Diesel.



Figure 2. Flower weight (a), THC (b) and terpene content (c) for Cherry Diesel flushed for 14, 10, 7 or 0 days before harvest. Significant differences are indicated at the 0.05 probability level.

Mineral Content of Flowers at Harvest
Flower samples taken the day before harvest were analyzed for content of essential plant nutrients. Overall, there was no significant change in the mineral content of flower as a result of different flushing treatments (Figure 3). In Cannabis flushed for 14 days, nitrogen was 6.7% lower than the zero-day flush treatment (Figure 3a). Continuing to feed nitrogen can increase its concentration in the plant, reducing the need for the plant to use its reserves for essential functions. Phosphorus, potassium, calcium, magnesium, and sulfur were similar for all four flushing treatments (Figure 3a-b).
There were changes in iron concentrations due to flushing treatments. Iron was at least 50 ppm higher in flower flushed for 14 or ten days (Figure 3c). Small changes were observed for zinc as well. Zinc was approximately 73 ppm higher in flower flushed for 14 days. The fluctuation in zinc did not follow a consistent pattern like iron. There was no significant change in manganese, boron, copper or molybdenum (Figure 3c). Nutrients like iron and zinc can accumulate in growing media over time. Feeding water during a flush may release some of these nutrients from the media into the plant. Additionally, zinc and iron are involved in the breakdown of chlorophyll occurring during senescence.
Data generated from plant parts, whether it be nutrient or THC concentrations, is naturally variable as only small samples of plants are consumed in the analysis. This may explain some of the variation seen in the data presented here. In other crops, ranges exist which indicate whether nutrient concentrations in leaves are deficient or sufficient for growth. All nutrient concentrations detected in this study are within generally accepted ranges of leaf concentrations for each nutrient. Toward the end of the Cannabis flowering cycle, the plant starts to naturally senescence. Plants that are nearing the end of their life cycle will uptake fewer nutrients as they remobilize nutrients from other plant parts. This may explain why little difference was observed in the mineral content of flower flushed for different times.




CONCLUSION
In a first of its kind study, Rx Green Technologies evaluated the effects of flushing period on yield, potency, terpenes, mineral content, and taste characteristics of Cannabis flower. Overall, the length of the flushing period did not impact yield, potency, terpenes, or taste characteristics of Cannabis flower. Taste test results indicated a trend toward improved flavor and smoke quality with the zero-day flush. While there were no significant differences in nutrient content, there was a trend toward increased iron and zinc in flower flushed for 14 days. The results of this trial indicate that there is no benefit to flushing Cannabis flower for improved taste or consumer experience.

 

B_the_s

Well-Known Member
Excellent timing for me. I might've started to flush next week.
Why do so many people swear by it?
 

LinguaPeel

Well-Known Member
Excellent timing for me. I might've started to flush next week.
Why do so many people swear by it?
Because reality and real plant science both exist. Cannabis scientists claim Skunk #1 smells like some Lisa Frank scented pencil eraser terpenes for fucks sake,and that more d9thc means more higher..

Here, want some real plant science?

Application of N3 and N4 decreased significantly the oil content (with 18.06% and 22.36%, respectively) compared with the control.

Total soluble sugars content was negatively influenced by nitrogen supply. The highest value was recorded in N2 with 93.4 mg·g−1 DW. After exposure to N3 and N4, a significant decrease of 10.70% and 16.27%, respectively, was recorded in the content of total soluble sugars.

N4 reduced the total phenolic content by 19.07%, when compared to the control. Similar observation was noted in total flavonoids content which decreased by 21.13% at N4

The total antioxidant activity was negatively influenced by high level of nitrogen application. In control the total antioxidant activity reached 503.77 ± 2.93 μg·g−1 DW, after the application of N4, this value decreased to 481.12 ± 1.9 μg·g−1 DW, reflecting a reduction of 16.40%.



Its common fuckin knowledge that un-flushed weed:

1)Smells and tastes like nutes (toothpaste, Chinese plastic, dog food) instead of like weed.

2) Is susceptible to mold.

3)Has no shelf life.

4) Can't be cured.

5) Doesnt even feel like weed if you're stupid enough to smoke it, it feels like smoking petrochemicals.


^ Scientific study done by me after moving to the southwest and realizing hydro growers are fucking retards who like smoking fertilizers, and think the nasty distinct plastic scents of unflushed petrochemicals = "gas terps".

Get back to me when RX Green Technologies figures out that there's sugars acidsesters thiols amines lactones aldehydes and all sorts of other good shit in my flushed weed, that doesn't exist in nasty overfed hydro garbage. Taste test panels show that people who grow and buy legal weed are retards. Who the fuck tests a diesel strain for terpenes? I'm sure Cherry Diesel is supposed to smell like fucking "earthy spicy" terpenes. To me that's exactly what a lot of this hydro shit smells like when you attempt to "cure" it (break down the nutes)
 

B_the_s

Well-Known Member
Because reality and real plant science both exist. Cannabis scientists claim Skunk #1 smells like some Lisa Frank scented pencil eraser terpenes for fucks sake,and that more d9thc means more higher..

Here, want some real plant science?

Application of N3 and N4 decreased significantly the oil content (with 18.06% and 22.36%, respectively) compared with the control.

Total soluble sugars content was negatively influenced by nitrogen supply. The highest value was recorded in N2 with 93.4 mg·g−1 DW. After exposure to N3 and N4, a significant decrease of 10.70% and 16.27%, respectively, was recorded in the content of total soluble sugars.

N4 reduced the total phenolic content by 19.07%, when compared to the control. Similar observation was noted in total flavonoids content which decreased by 21.13% at N4

The total antioxidant activity was negatively influenced by high level of nitrogen application. In control the total antioxidant activity reached 503.77 ± 2.93 μg·g−1 DW, after the application of N4, this value decreased to 481.12 ± 1.9 μg·g−1 DW, reflecting a reduction of 16.40%.



Its common fuckin knowledge that un-flushed weed:

1)Smells and tastes like nutes (toothpaste, Chinese plastic, dog food) instead of like weed.

2) Is susceptible to mold.

3)Has no shelf life.

4) Can't be cured.

5) Doesnt even feel like weed if you're stupid enough to smoke it, it feels like smoking petrochemicals.


^ Scientific study done by me after moving to the southwest and realizing hydro growers are fucking retards who like smoking fertilizers, and think the nasty distinct plastic scents of unflushed petrochemicals = "gas terps".

Get back to me when RX Green Technologies figures out that there's sugars acidsesters thiols amines lactones aldehydes and all sorts of other good shit in my flushed weed, that doesn't exist in nasty overfed hydro garbage. Taste test panels show that people who grow and buy legal weed are retards. Who the fuck tests a diesel strain for terpenes? I'm sure Cherry Diesel is supposed to smell like fucking "earthy spicy" terpenes. To me that's exactly what a lot of this hydro shit smells like when you attempt to "cure" it (break down the nutes)
First I was like "Ok" then baffled by N2 3 and 4 then intrigued and then you said "Taste test panels show that people who grow and buy legal weed are retards." and I laughed out loud and then thought "Who is tasting the retards?"

So I guess flushing is still hotly contested. Are there ANY examples where EVERYONE agrees that a flush is beneficial or detrimental? ie. strain, growing media, brand/type of nutrients, any other additive or amendment
 

IrkinBollikans

Well-Known Member
First I was like "Ok" then baffled by N2 3 and 4 then intrigued and then you said "Taste test panels show that people who grow and buy legal weed are retards." and I laughed out loud and then thought "Who is tasting the retards?"

So I guess flushing is still hotly contested. Are there ANY examples where EVERYONE agrees that a flush is beneficial or detrimental? ie. strain, growing media, brand/type of nutrients, any other additive or amendment
No examples. Flushing is for toilets
 

cannabineer

Ursus marijanus
SUMMARY
  • Rx Green Technologies evaluated the effects of different flushing times on chemical profile, flavor, and smoking characteristics in Cannabis flower.
  • Flushing periods of 14, 10, 7 and 0 days were imposed on Cherry Diesel.
  • No differences were detected between flush treatments for yield, potency, or terpenes.
  • Analysis of mineral content of leaves indicated small changes in content of iron and zinc.
  • Taste test panelists tended to prefer flower flushed for 0 days.
INTRODUCTION
Taste and combustion qualities of Cannabis are dependent on the chemical characteristics of the flower. These chemical characteristics can be influenced by management practices during the growing cycle. For this reason, many Cannabis growers implement a flushing period where only water is fed to plants in the final days to weeks before harvest. While many cultivators attest to the effects of a flush, no scientific studies have been conducted to validate this practice. Rx Green Technologies has undertaken a first of its kind study to determine the influence of different flushing times on the chemical profile, flavor, and combustion characteristics of Cannabis flower.

MATERIALS AND METHODS
Cannabis variety Cherry Diesel (Cherry OG x Turbo Diesel) was grown at the Rx Green Technologies R&D Facility using Rx Green Technologies nutrients and Clean Coco. Grow A, Grow B and E-Plus were fed during the vegetative stage and Bloom A, Bloom B, E-Plus, and Bulk were fed during the flowering cycle. The first flushing period began 14 days before harvest. The other flushing periods were ten, seven, and zero days before harvest. Each flushing period was tested on 12 different Cherry Diesel plants divided into four different groups (replications) spread evenly across the flowering room tables. Flower and fan leaf samples were collected from each flushing treatment the first day of flush and the day before harvest to quantify concentrations of essential plant nutrients. After harvest, trial plants were cured before determining final trimmed flower weight, terpene and THC concentrations. Trim was evaluated by an extractor for THC, yield, and appearance of the extract or “wax”.
To determine smoking flavor and characteristics, samples of each flushing period were distributed to Cannabis industry experts in a blind taste test. Each participant received one sample of each flushing time without knowledge of its treatment. Participants were asked about their personal Cannabis flavor preferences before tasting. After tasting, participants were asked to rate the sample for flavor, harshness of smoke, and color of ash.
Data collected during the course of the trial were analyzed statistically to determine whether flushing times affected smoking quality, flower weight, or chemical characteristics of Cannabis. Statistical analysis of data allows us to quantify whether differences in the numbers are due to the treatments imposed or are results of the natural variations observed when growing plants.

RESULTS AND DISCUSSION
Visual differences in fan leaves between flushing times were apparent the day before harvest. Plants flushed for ten or 14 days had leaves that were more yellow, necrotic and dry than plants flushed for zero or seven days (Figure 1a-d). The color of the 14 and ten day flushed leaves indicates a greater breakdown of chlorophyll in the plant, leading to reduced greenness

Figure 1. Fan leaves collected from Cherry Diesel plants the day before harvest. Flushing times depicted are (a) 14 days, (b) 10 days, (c) 7 days, and (d) 0 days.

Yield, THC, and Terpenes
The flower weight, THC and terpene content of cured flower were determined for each flushing period. The data were analyzed statistically to determine whether the numerical differences in the data were due to the treatment. Overall, there were no significant differences between treatments for flower weight, THC or terpene content (Figure 2a-c) (P < 0.05). Flower weight per plant averaged 97.3 g and THC content averaged 21.9%. The dominant terpenes in the flower were beta-myrcene, beta-caryophyllene, and terpinolene, giving the flower an earthy and spicy smell (Figure 2c). Overall, flushing times did not impact flower weight, THC, or terpenes in Cherry Diesel.



Figure 2. Flower weight (a), THC (b) and terpene content (c) for Cherry Diesel flushed for 14, 10, 7 or 0 days before harvest. Significant differences are indicated at the 0.05 probability level.

Mineral Content of Flowers at Harvest
Flower samples taken the day before harvest were analyzed for content of essential plant nutrients. Overall, there was no significant change in the mineral content of flower as a result of different flushing treatments (Figure 3). In Cannabis flushed for 14 days, nitrogen was 6.7% lower than the zero-day flush treatment (Figure 3a). Continuing to feed nitrogen can increase its concentration in the plant, reducing the need for the plant to use its reserves for essential functions. Phosphorus, potassium, calcium, magnesium, and sulfur were similar for all four flushing treatments (Figure 3a-b).
There were changes in iron concentrations due to flushing treatments. Iron was at least 50 ppm higher in flower flushed for 14 or ten days (Figure 3c). Small changes were observed for zinc as well. Zinc was approximately 73 ppm higher in flower flushed for 14 days. The fluctuation in zinc did not follow a consistent pattern like iron. There was no significant change in manganese, boron, copper or molybdenum (Figure 3c). Nutrients like iron and zinc can accumulate in growing media over time. Feeding water during a flush may release some of these nutrients from the media into the plant. Additionally, zinc and iron are involved in the breakdown of chlorophyll occurring during senescence.
Data generated from plant parts, whether it be nutrient or THC concentrations, is naturally variable as only small samples of plants are consumed in the analysis. This may explain some of the variation seen in the data presented here. In other crops, ranges exist which indicate whether nutrient concentrations in leaves are deficient or sufficient for growth. All nutrient concentrations detected in this study are within generally accepted ranges of leaf concentrations for each nutrient. Toward the end of the Cannabis flowering cycle, the plant starts to naturally senescence. Plants that are nearing the end of their life cycle will uptake fewer nutrients as they remobilize nutrients from other plant parts. This may explain why little difference was observed in the mineral content of flower flushed for different times.




CONCLUSION
In a first of its kind study, Rx Green Technologies evaluated the effects of flushing period on yield, potency, terpenes, mineral content, and taste characteristics of Cannabis flower. Overall, the length of the flushing period did not impact yield, potency, terpenes, or taste characteristics of Cannabis flower. Taste test results indicated a trend toward improved flavor and smoke quality with the zero-day flush. While there were no significant differences in nutrient content, there was a trend toward increased iron and zinc in flower flushed for 14 days. The results of this trial indicate that there is no benefit to flushing Cannabis flower for improved taste or consumer experience.

The one thing missing from this is a primary reference to a peer-reviewed source.

What I see is a commercial deceptively cloaked in jargon.

Scientific study, [heavy sarcasm] indeeed.
 

IrkinBollikans

Well-Known Member
Never in my life experienced bud that tastes/smells like dog food or toothpaste. No clue what Chinese plastic might smell like, but if it smells like plastic from any other race, I've also not experienced this. Also not sure why flushed buds would be more resistant to mold/rot. This needs to get moved to the broscience thread
 

cannabineer

Ursus marijanus
Never in my life experienced bud that tastes/smells like dog food or toothpaste. No clue what Chinese plastic might smell like, but if it smells like plastic from any other race, I've also not experienced this. Also not sure why flushed buds would be more resistant to mold/rot. This needs to get moved to the broscience thread
The first time I see a J. Bro Sci. ref in one of the learned journals, I’m gonna laugh up most of a lung.
 

cannabineer

Ursus marijanus
How about a non-biased study that isn't done by a nutrient company? Of course they want you pumping their products until harvest day.
The simplest way to minimize bias is to publish in a peer-reviewed journal. Each field has a few such. Anything else is tier 2.
 
How about a non-biased study that isn't done by a nutrient company? Of course they want you pumping their products until harvest day.
If flushing makes no difference, then you can save your nutrients in the last two weeks. They're really not benefiting from the results. You still made a valid point. You can't have a conflict of interest in a scientific study.
 
Never in my life experienced bud that tastes/smells like dog food or toothpaste. No clue what Chinese plastic might smell like, but if it smells like plastic from any other race, I've also not experienced this. Also not sure why flushed buds would be more resistant to mold/rot. This needs to get moved to the broscience thread
Me neither, but it sounds interesting.
 

B_the_s

Well-Known Member
1596118124804.png
My mfr nutrient schedule shows a flush week that excludes most of the nutrients from the feed water.
But still does include "Rezin" and "Liquid Weight". I haven't seen an actual NPK or nutrient breakdown for any of these nutrient solutions.
 

overdose420

Well-Known Member
Because reality and real plant science both exist. Cannabis scientists claim Skunk #1 smells like some Lisa Frank scented pencil eraser terpenes for fucks sake,and that more d9thc means more higher..

Here, want some real plant science?

Application of N3 and N4 decreased significantly the oil content (with 18.06% and 22.36%, respectively) compared with the control.

Total soluble sugars content was negatively influenced by nitrogen supply. The highest value was recorded in N2 with 93.4 mg·g−1 DW. After exposure to N3 and N4, a significant decrease of 10.70% and 16.27%, respectively, was recorded in the content of total soluble sugars.

N4 reduced the total phenolic content by 19.07%, when compared to the control. Similar observation was noted in total flavonoids content which decreased by 21.13% at N4

The total antioxidant activity was negatively influenced by high level of nitrogen application. In control the total antioxidant activity reached 503.77 ± 2.93 μg·g−1 DW, after the application of N4, this value decreased to 481.12 ± 1.9 μg·g−1 DW, reflecting a reduction of 16.40%.



Its common fuckin knowledge that un-flushed weed:

1)Smells and tastes like nutes (toothpaste, Chinese plastic, dog food) instead of like weed.

2) Is susceptible to mold.

3)Has no shelf life.

4) Can't be cured.

5) Doesnt even feel like weed if you're stupid enough to smoke it, it feels like smoking petrochemicals.


^ Scientific study done by me after moving to the southwest and realizing hydro growers are fucking retards who like smoking fertilizers, and think the nasty distinct plastic scents of unflushed petrochemicals = "gas terps".

Get back to me when RX Green Technologies figures out that there's sugars acidsesters thiols amines lactones aldehydes and all sorts of other good shit in my flushed weed, that doesn't exist in nasty overfed hydro garbage. Taste test panels show that people who grow and buy legal weed are retards. Who the fuck tests a diesel strain for terpenes? I'm sure Cherry Diesel is supposed to smell like fucking "earthy spicy" terpenes. To me that's exactly what a lot of this hydro shit smells like when you attempt to "cure" it (break down the nutes)
Haven't responded to anything here for a loooong time.. but I had to for this... FLUSH YOUR FLOWERS.. DONT BE LAZY.. This research is wrong. Your flavors come from flushing.. Your smoke quality comes from flushing... and the list goes on.
To this day, bad information spreads‍♂
 

bk78

Well-Known Member
Haven't responded to anything here for a loooong time.. but I had to for this... FLUSH YOUR FLOWERS.. DONT BE LAZY.. This research is wrong. Your flavors come from flushing.. Your smoke quality comes from flushing... and the list goes on.
To this day, bad information spreads‍♂
Speaking of bad information

read this post kids, it’s awful information.
 
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