Whats All The Hullaballoo On Internodes? Well Lets Talk About It

jumpincactus

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There is a lot of varying discussion concerning controlling internode distance and many different approaches to controlling the dreaded stretch especially with a lot of indoor guys and gals where vertical space is at a premium. The bottom line is, internode distance and the longer the stem length is between nodes = wasted real estate you are sacrificing for floral cluster development. I used to love Ex's sig line from Exotic Genetics and it went "tight azz farmer" :) Keeping short tight internode distance can and does produce denser more compact floral clusters/colas. One of the best things I have taken away from all the available data out there in controlling stretch is one, limiting the amount of red/far red light during veg. So I quit using HPS for vegetative growth and I have known lots of farmers over the years that use HPS for all stages of growth. So lose the reds and keep it blue when vegging.

To add, it is also very useful and I use this method myself, is when flipping to flower for the 1st 2-3 weeks I keep the light blue. I do not use a hps bulb during the 1st weeks of flower. Keeping the blue spectrum during the time the plant stretches the most keeps the nodes closer n tighter, which equals more bud sites. It is also helpful to run mixed spectrum during the balance of flower to keep it tight. Use both MH and hps to bring the crop home. The following is a list of some other techniques to assure you use every bit of stem length to develop bud sites and not useless stem. It contains some very good suggestions that I have used since I found this info years ago. I take no credit for the content as it is not my creation. Just spreading the love for your perusal and use.

PS pay attention to the underlined paragraph speaking to letting cannabis dry out completely between watering/feeding. There are a lot of suggestions out there but this one makes the most sense to me in my personal experience........ Take what you want and leave the rest........ Peace

Here is the additional information I spoke of,,,,,,,,,,

Why waste light and electricity growing stem? Stretched-out plants are the bane of indoor growers. There are several ways to reduce internodal length and thus grow denser, more efficient buds.
Temperature control

The easiest and most under-used way to control internodal stretch is temperature control. Plant internodal length is directly related to the difference between day and night temperatures, the warmer your day cycle is as compared to your night cycle, the greater your internode length will be. The opposite also holds true; the closer your day and night temperatures, the shorter your internodes will be. Ever notice how as the warmer summer months approach, your plants begin to stretch? Part of this problem may lie in an overall hotter grow-room, but a larger factor is the increased difference between day and night temperatures.

Lets look at putting this to play in your grow room. Maximum temperatures should ideally never rise above 26 deg C or 78.8 deg F, so you must do everything you can to prevent your room getting too hot (run lights at night, use exhaust fans, air conditioners, etc). An ideal temperature range is 24-25 deg C or 75.2 deg F when the lights are on, and 22 deg C or 71.6 deg F when the lights are off.

The temperature technique is most effective under a 12/12 light regime, which is ideal as this is when cannabis stretches the most. When the light cycle is brought to 12/12 we will raise the night temperature to the daytime level of 24-25 C 75.2 /77 deg F. Space heaters on timers work well for this, and max/min type thermometers are ideal for tracking temperatures.

It is during the first 2-3 weeks of the flower cycle that most strains begin to lengthen internodes, making it a very important time to control temperature, as this is when the framework for future colas is built. After this 2-3 week window we need to drop the night temperature back down to 22 deg C or 71.6 deg F, as this is where the plant is happiest.

As floral development begins we need to keep in mind that the total size of your buds is determined largely by average daily temperature, provided it does not exceed optimal. So if you are letting your day temperatures drop below 24 deg C/75.2 deg F or your night drop below 22 deg C / 71.6 deg F, you are costing yourself in overall weight and harvest.

Once your buds have reached optimal size and and you have begun the flushing period, you may consider dropping temperature down to 17-19 deg C / 62.6-66.2 deg F for the final week or two. This drop in temperature triggers anthocyanin production, which intensifies the colour of the floral clusters and makes for a showier bud, especially with "purple" varieties. This final temperature change is not always feasible and can be omitted.

For extreme height control you may even use warmer night temperature than day, but be very careful when running settings like this, as even a zero difference between night and day temperatures will lead to leaf chlorosis (yellowing) after 2-3 weeks.

Some things you will notice while using this technique are a change in the leaf angle, upwards during warm days and downwards during warm nights. There is also the chlorosis if this is done for too long. Neither of these symptoms is nutrient related and will fix themselves when the temperature is changed back.

Whether you're growing hydro or in soil, the electrical conductivity (EC) and moisture of your medium are two key elements that should be manipulated to meet your needs. Both of these factors are controlling the same thing; the ability of a plant to uptake water and nutrients from the growth medium. (EC measures the level of fertilizer salts in the water.)

A plant grows by first dividing cells then expanding them, and in order to do this it requires water. By limiting the amount of water available to a plant you limit the expansion of cells. This can work for you by keeping your internodes close together, or against you by limiting bud growth. Both the amount of water you give your plants and the EC at which you grow them control the uptake of water.

A plant's roots act much like a pump, using osmotic pressure to move water into the plant. In order for this to work there must be a larger concentration of fertilizer salts in the plant's roots than in the soil or hydroponic solution, so when the medium's level of salt rises above the roots', the plant will wilt. Raising the salt level in the medium closer to that which is in the roots limits the water availability just the same as if we had provided less water.

During the vegetative stage we want our plants to form very tight internodes, especially under artificial lighting. By allowing the EC to drop below ideal during this stage we are wasting valuable space growing stem instead of bud. Most marijuana strains are happiest when grown at an EC of between 1.5 and 1.8, but different strains have different preferences. Try growing one of your plants using straight water for a week or so, you will see the internode length stretch dramatically compared to the ones on a regular fertilizer regime.

Hydroponic tomato growers sometimes will grow their transplants at extremely high EC's (up to 6 EC!) in order to get really nice stocky production plants. Please note that when doing this they use special nutrient formulas designed for this purpose, most of which have potassium to nitrogen ratios of 4:1, much higher than normal, as too much nitrate at this high an EC will easily damage a plant.

(Try this formula if you're interested: calcium nitrate 7 grams, potassium nitrate 0.095 grams, potassium sulphate 9.25 grams, mono potassium phosphate 2.2 gram, magnesium sulphate 5 grams, micromix .02 grams. Slowly raise your EC during veg stage, I would not recommend going above 3 or 4 EC. This is experimental! Do not try on all of your plants at once until you are sure your strain can handle it. All of these ingredients should be available at your local hydroponics store, it is usually called "six pack formula". Be sure to bring your EC back down once you enter floral stage, by the time tufts of pistils are visible you want to be at your ideal EC of 1.5-1.8.)

Try not to change the EC too quickly as a sharp drop can cause root damage. This also goes during your final flushing period when you want to eliminate all fertilizer from the medium ? lower the EC over a couple of days, as the sudden change in salt level will harm the roots.

When growing hydroponically, the only way of manipulating water availability is with the EC, while in soil we may also use the moisture level of the medium to the same ends. Many growers are under the mistaken impression that the EC and pH of their nutrient solution remains the same when applied to the soil. This in not the case, and you must test the soil in order to have a true
picture.

To test your soil, take a sample from the center of the root zone at the side of the pot (don't worry the torn roots will be fine). Mix the soil with 2 equal parts distilled water and let sit for 20 minutes. Once the time is up take an EC reading and multiply this number by 2.4 (this takes into account the dilution and the pore space factor) this will give you an accurate picture of the EC the roots are actually being exposed to. The pH should also be checked at this time. It is not feasible in soil to maintain an exact EC at all times, what we need to try and avoid is EC's climbing much above what we want and plants going for long periods with very low EC's.

A frequent mistake marijuana growers make is over-emphasizing the need for a plant grown in soil to dry out completely between waterings. Cannabis does like dry feet, but this simply means that the root zone must not be kept extremely wet at all times. Keep in mind that if the soil has an EC of 1.8 and then dries out completely the amount of salt remains the same, causing the EC to double or more.

As a general rule, during the vegetative stage you should keep your plants a little on the drier side as this will restrict cell elongation, creating a shorter noded plant structure capable of creating a dense bud cluster in the floral stage. (Unless of course you are using the high EC method described above, in this case you must not let your soil get too dry because of the increased fertilizer level you will create.) Maintain this level of moisture into the first 14 to 20 days of 12/12 to minimize internode stretch.

As soon as early flowering begins you need to increase soil moisture to a nice evenly moist (not soaked) level to maximize bud expansion. Growing marijuana too dry during this stage will adversely affect your overall yield, as will having too high an EC in the medium.

In these times of government oppression we must make the most efficient use of available growing space in order to produce the copious amounts of cannabis necessary to overflow the boundaries placed upon us. Control your cannabis! posted by BTY
 
9,641
313
thank you sir. im at that stage now looking at nodes e tc.

this was helpful. especially the drying out part. ( right now with out my tent setup, they are having cool;er days than nights )

i get it, will help me with teh solo cup 17.. that thing is gonna be a hand full in my environment. laughs

hope you are having a great day, got my ass kicked last night by that waxy stuff. laughs.. :LD
chris.
 

GT21

I like soup
Supporter
10,119
438
There is a lot of varying discussion concerning controlling internode distance and many different approaches to controlling the dreaded stretch especially with a lot of indoor guys and gals where vertical space is at a premium. The bottom line is, internode distance and the longer the stem length is between nodes = wasted real estate you are sacrificing for floral cluster development. I used to love Ex's sig line from Exotic Genetics and it went "tight azz farmer" :) Keeping short tight internode distance can and does produce denser more compact floral clusters/colas. One of the best things I have taken away from all the available data out there in controlling stretch is one, limiting the amount of red/far red light during veg. So I quit using HPS for vegetative growth and I have known lots of farmers over the years that use HPS for all stages of growth. So lose the reds and keep it blue when vegging.

To add, it is also very useful and I use this method myself, is when flipping to flower for the 1st 2-3 weeks I keep the light blue. I do not use a hps bulb during the 1st weeks of flower. Keeping the blue spectrum during the time the plant stretches the most keeps the nodes closer n tighter, which equals more bud sites. It is also helpful to run mixed spectrum during the balance of flower to keep it tight. Use both MH and hps to bring the crop home. The following is a list of some other techniques to assure you use every bit of stem length to develop bud sites and not useless stem. It contains some very good suggestions that I have used since I found this info years ago. I take no credit for the content as it is not my creation. Just spreading the love for your perusal and use.

PS pay attention to the underlined paragraph speaking to letting cannabis dry out completely between watering/feeding. There are a lot of suggestions out there but this one makes the most sense to me in my personal experience........ Take what you want and leave the rest........ Peace

Here is the additional information I spoke of,,,,,,,,,,

Why waste light and electricity growing stem? Stretched-out plants are the bane of indoor growers. There are several ways to reduce internodal length and thus grow denser, more efficient buds.
Temperature control

The easiest and most under-used way to control internodal stretch is temperature control. Plant internodal length is directly related to the difference between day and night temperatures, the warmer your day cycle is as compared to your night cycle, the greater your internode length will be. The opposite also holds true; the closer your day and night temperatures, the shorter your internodes will be. Ever notice how as the warmer summer months approach, your plants begin to stretch? Part of this problem may lie in an overall hotter grow-room, but a larger factor is the increased difference between day and night temperatures.

Lets look at putting this to play in your grow room. Maximum temperatures should ideally never rise above 26 deg C or 78.8 deg F, so you must do everything you can to prevent your room getting too hot (run lights at night, use exhaust fans, air conditioners, etc). An ideal temperature range is 24-25 deg C or 75.2 deg F when the lights are on, and 22 deg C or 71.6 deg F when the lights are off.

The temperature technique is most effective under a 12/12 light regime, which is ideal as this is when cannabis stretches the most. When the light cycle is brought to 12/12 we will raise the night temperature to the daytime level of 24-25 C 75.2 /77 deg F. Space heaters on timers work well for this, and max/min type thermometers are ideal for tracking temperatures.

It is during the first 2-3 weeks of the flower cycle that most strains begin to lengthen internodes, making it a very important time to control temperature, as this is when the framework for future colas is built. After this 2-3 week window we need to drop the night temperature back down to 22 deg C or 71.6 deg F, as this is where the plant is happiest.

As floral development begins we need to keep in mind that the total size of your buds is determined largely by average daily temperature, provided it does not exceed optimal. So if you are letting your day temperatures drop below 24 deg C/75.2 deg F or your night drop below 22 deg C / 71.6 deg F, you are costing yourself in overall weight and harvest.

Once your buds have reached optimal size and and you have begun the flushing period, you may consider dropping temperature down to 17-19 deg C / 62.6-66.2 deg F for the final week or two. This drop in temperature triggers anthocyanin production, which intensifies the colour of the floral clusters and makes for a showier bud, especially with "purple" varieties. This final temperature change is not always feasible and can be omitted.

For extreme height control you may even use warmer night temperature than day, but be very careful when running settings like this, as even a zero difference between night and day temperatures will lead to leaf chlorosis (yellowing) after 2-3 weeks.

Some things you will notice while using this technique are a change in the leaf angle, upwards during warm days and downwards during warm nights. There is also the chlorosis if this is done for too long. Neither of these symptoms is nutrient related and will fix themselves when the temperature is changed back.

Whether you're growing hydro or in soil, the electrical conductivity (EC) and moisture of your medium are two key elements that should be manipulated to meet your needs. Both of these factors are controlling the same thing; the ability of a plant to uptake water and nutrients from the growth medium. (EC measures the level of fertilizer salts in the water.)

A plant grows by first dividing cells then expanding them, and in order to do this it requires water. By limiting the amount of water available to a plant you limit the expansion of cells. This can work for you by keeping your internodes close together, or against you by limiting bud growth. Both the amount of water you give your plants and the EC at which you grow them control the uptake of water.

A plant's roots act much like a pump, using osmotic pressure to move water into the plant. In order for this to work there must be a larger concentration of fertilizer salts in the plant's roots than in the soil or hydroponic solution, so when the medium's level of salt rises above the roots', the plant will wilt. Raising the salt level in the medium closer to that which is in the roots limits the water availability just the same as if we had provided less water.

During the vegetative stage we want our plants to form very tight internodes, especially under artificial lighting. By allowing the EC to drop below ideal during this stage we are wasting valuable space growing stem instead of bud. Most marijuana strains are happiest when grown at an EC of between 1.5 and 1.8, but different strains have different preferences. Try growing one of your plants using straight water for a week or so, you will see the internode length stretch dramatically compared to the ones on a regular fertilizer regime.

Hydroponic tomato growers sometimes will grow their transplants at extremely high EC's (up to 6 EC!) in order to get really nice stocky production plants. Please note that when doing this they use special nutrient formulas designed for this purpose, most of which have potassium to nitrogen ratios of 4:1, much higher than normal, as too much nitrate at this high an EC will easily damage a plant.

(Try this formula if you're interested: calcium nitrate 7 grams, potassium nitrate 0.095 grams, potassium sulphate 9.25 grams, mono potassium phosphate 2.2 gram, magnesium sulphate 5 grams, micromix .02 grams. Slowly raise your EC during veg stage, I would not recommend going above 3 or 4 EC. This is experimental! Do not try on all of your plants at once until you are sure your strain can handle it. All of these ingredients should be available at your local hydroponics store, it is usually called "six pack formula". Be sure to bring your EC back down once you enter floral stage, by the time tufts of pistils are visible you want to be at your ideal EC of 1.5-1.8.)

Try not to change the EC too quickly as a sharp drop can cause root damage. This also goes during your final flushing period when you want to eliminate all fertilizer from the medium ? lower the EC over a couple of days, as the sudden change in salt level will harm the roots.

When growing hydroponically, the only way of manipulating water availability is with the EC, while in soil we may also use the moisture level of the medium to the same ends. Many growers are under the mistaken impression that the EC and pH of their nutrient solution remains the same when applied to the soil. This in not the case, and you must test the soil in order to have a true
picture.

To test your soil, take a sample from the center of the root zone at the side of the pot (don't worry the torn roots will be fine). Mix the soil with 2 equal parts distilled water and let sit for 20 minutes. Once the time is up take an EC reading and multiply this number by 2.4 (this takes into account the dilution and the pore space factor) this will give you an accurate picture of the EC the roots are actually being exposed to. The pH should also be checked at this time. It is not feasible in soil to maintain an exact EC at all times, what we need to try and avoid is EC's climbing much above what we want and plants going for long periods with very low EC's.

A frequent mistake marijuana growers make is over-emphasizing the need for a plant grown in soil to dry out completely between waterings. Cannabis does like dry feet, but this simply means that the root zone must not be kept extremely wet at all times. Keep in mind that if the soil has an EC of 1.8 and then dries out completely the amount of salt remains the same, causing the EC to double or more.

As a general rule, during the vegetative stage you should keep your plants a little on the drier side as this will restrict cell elongation, creating a shorter noded plant structure capable of creating a dense bud cluster in the floral stage. (Unless of course you are using the high EC method described above, in this case you must not let your soil get too dry because of the increased fertilizer level you will create.) Maintain this level of moisture into the first 14 to 20 days of 12/12 to minimize internode stretch.

As soon as early flowering begins you need to increase soil moisture to a nice evenly moist (not soaked) level to maximize bud expansion. Growing marijuana too dry during this stage will adversely affect your overall yield, as will having too high an EC in the medium.

In these times of government oppression we must make the most efficient use of available growing space in order to produce the copious amounts of cannabis necessary to overflow the boundaries placed upon us. Control your cannabis! posted by BTY
Good stuff.. i like physical manipulation. . Just moving around the branches to mimic wind will strengthen and shorten internode length
 
847
143
All valid points.... Being a long veg/tree grower myself keeping them squat is paramount.... I would say the single biggest factor for keeping nodes tight is to not crowd your plants ; HPS or mh matters less ime. As soon as leaves start overlapping ,whether it's a plant shading itself or its neighbors , the plants will stretch regardless of hid. I veg with mostly HPS and get very little stretch until they start crowding. Should be noted I use Hortilux HPS which does have 25% more blue I'm sure that helps. I also feed organic kelp which contains pgrs that make a plant more squat, cytokinins I believe (could be wrong on that). Genetics is huge too. Peace
 

jumpincactus

Premium Member
Supporter
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All valid points.... Being a long veg/tree grower myself keeping them squat is paramount.... I would say the single biggest factor for keeping nodes tight is to not crowd your plants ; HPS or mh matters less ime. As soon as leaves start overlapping ,whether it's a plant shading itself or its neighbors , the plants will stretch regardless of hid. I veg with mostly HPS and get very little stretch until they start crowding. Should be noted I use Hortilux HPS which does have 25% more blue I'm sure that helps. I also feed organic kelp which contains pgrs that make a plant more squat, cytokinins I believe (could be wrong on that). Genetics is huge too. Peace
Agree with the crowding, its a condition in plants called Alleopathy. Crowding can bring out the plants WMD's using chemical warfare to limits its neighbors growth. Sort of but different process of quorum sensing in the rhizosphere.
 
879
243
thank you sir. im at that stage now looking at nodes e tc.

this was helpful. especially the drying out part. ( right now with out my tent setup, they are having cool;er days than nights )

i get it, will help me with teh solo cup 17.. that thing is gonna be a hand full in my environment. laughs

hope you are having a great day, got my ass kicked last night by that waxy stuff. laughs.. :LD
chris.
What ever happened to the jippster?
 

jumpincactus

Premium Member
Supporter
11,636
438
Control Your Plants by Controlling Your DIF: A Guide to Daytime and Nighttime Temperature Differential

While earlier in this thread I talked about blue and red spectrums to help control internode distances, This is another way of keeping your nodes tighter with more compact floral clusters. try it really does work. :cool:

Controlling all aspects of your garden will repay you in spades. Indoor gardening is all about control; control over photoperiod, control over temperature, control over plant nutrition, etc. By controlling everything from the photoperiod to the specific nutrition a plant receives, we effectively remove all barriers that may hinder our plants; optimally that control will allow them to reach their maximum genetic potential. An often overlooked environmental factor that can greatly impact your plants is the DIF, or the day night differential. DIF is the difference in the highest day time (lights on) temperature and the lowest night time (lights off) temperature. Control over your DIF will give you control over your plant’s height and internodal spacing without the use of dangerous or untested chemicals or plant growth regulators.

Research about DIF is not new to science; back in 1944, Went made detailed observations about the effect of the night time temperature (Tn) on the stem growth rates of tomato plants. He originally proposed the term ‘thermoperiodicity’ to describe the apparently greater rate of plant growth and development in diurnally fluctuating temperatures compared to plants grown at constant temperatures. Although his research was disproven in 1990 by Ellis et al, Went’s research was the beginning of our attempts to understand the impact of temperature on plant growth.

In 1983 while studying the effects of temperature on the Easter Lily (Lilium longiflorum), it was observed that there was an interaction between day and night temperatures that affected the length of the floral stem. This relationship, coined DIF (Erwin et al, 1989), was used to describe the elongation of the stem in response to diurnal thermoperiod and photoperiod interaction. They noted that the magnitude and nature of the internodal elongation varied between different species and also between different cultivars of the same species.

Plant height or stem length is simply the sum of the lengths of each of the internodes. Therefore, to control plant height one must manage internode number, internode length, or both. The number of nodes and the length of each internode (the distance from one node to the next) are strongly influenced by temperature. As DIF increases, so does the internode length of most plants. It is important to understand that the effect of DIF on internode length is due to increased cell elongation, and not an increased number of individual plant cells. Plants respond rapidly to changes in DIF, with altered growth rates that are often observable in as little as 24 hours.

Although managing your garden’s DIF will afford you some control over your plant’s internodal elongation, there are factors that influence or compound the DIF response. The Average daily temperature influences internode length and thus the response to DIF in many plants. The quality of the light being received by your plants has been shown to influence the DIF response, presumably through effects related to phytochrome photoequalibria (Moe and Heins, 1990). While incandescent lighting used for photoperiod control can eliminate a plant’s response to DIF, fluorescent lighting has been shown to increase the response (Moe et al, 1991).

With the proven effects of DIF at controlling plant height, how do you exploit this information to grow a better garden? First, day time and night time temperatures must be controlled independently and excess humidity must be removed from the air by using dehumidifiers. Watch for significant increases in your DIF; a large swing between your day time and night time temperature will bring a marked increase in humidity. If the high night time humidity level is left unchecked it can lead to mold and disease on your fruits and flowers.

During the vegetative light cycle (18 on, 6 off), your target DIF should be 5 degrees Fahrenheit. Try to maintain a daytime or “lights on” temperature of 85 degrees Fahrenheit, and 80 degrees Fahrenheit when the lights are off. For the blooming or fruiting phase of your plant’s life cycle (12 on, 12 off), your target DIF should still be 5 degrees Fahrenheit; but the daytime “lights on” maximum temperature should be limited to 80 degrees Fahrenheit, and your “lights off” temperature to 75 degrees Fahrenheit. By maintaining the DIF at 5 degrees your plants will exhibit the tightest internodal growth, lowering the overall size of your plants while building a tight network of branches. Remember that the temperature and DIF recommendations above are starting points as different species and cultivars (or clones) will react differently to a controlled DIF. Controlling your DIF could make all the difference to your garden!
 
Does anyone else use two different light intensities to simulate natural day intensites/ save energy? I did it mostly to save 55% energy but honestly the plants look healthier and grow extremely fast in veg with good internode spacing of about 2 inches, not overtight or overstretched. 5/7/6/6 low, high, low, off. To mimic early morning, noon, evening and finally night. I flower 1/8/2/13 low, high, low, off to mimic strong shorts days of early fall in the northern hemisphere.
 
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