how to reduce internodal space

coreywebster

Well-Known Member
that would be a good start. leds are good but not necessary. a good t5 florescent fixture works fine for veg, you just have to raise the plants up to it till they start to grow the way you want them
Yeah the LED bit is a bit misleading since they come in all spectrums and intensities. I found a long time ago that cfl in 6500k made stupidly short internodes, so stupid it was detrimental, but that shows spectrum can play a huge part.
 

Dougs Nugs

Well-Known Member
reducing nitrogen and phosphorus during the first 2-3 weeks of flower as well as using more blue light in general in veg and during early flowering period can help keep the nodes tight during stretch phase.

also keeping night temps within 5 degrees of day temperatures will reduce stretch
The temperature, light distance and pre loading the plant with enough NPK as there will be vigorous uptake.

Kelp and Humic acids are a huge win, foliar feeding during the first two weeks. you will be very pleased

Happy growing

Doug
 

10WeekFlushBro

Well-Known Member
There is this guy on reddit who seems to be a master of short internodes. He puts blue light on the stem and calls it selective light training. Google for "SuperAngryGuy" all credit to him. I don't like reddit, but it seems that he only hangs out there
Pea plant: Jack herer:
Mystery skunk


I'd prefer a normal plant, but if short nodes what youre after this looks most promising.
Oh yeah, and PGRs :P
 

10WeekFlushBro

Well-Known Member
Yeah I was shocked when I saw that. I dont know the guy but he wrote a lot of interesting stuff, definitely worth checkin out via a web search on his name. Cheers
 

Flowki

Well-Known Member
In veg continually top nodes that are getting higher than the rest. The continues redirection keeps them smaller but you get more tops at the same height. A final topping a week before flip is fine if your growth is fast, you'll have to define what fast is. At flip, put a net about 6" above plants if you can, use this to tuck any dominant tops while others catch up. You can use 4 bamboo sticks per pot to do the same job if net isn't an option. It isn't as good as a net though. You will only need to bother tucking or tying every other day during stretch, wouldn't recommend any less than that.

With hps 18" height is usually good quality/yield for most 600w hps units. With cob/hlg etc it is more difficult to find the right range as the plants can still suffer light stress with no leaf curl. Yes it will keep them smaller but not in a good way. I don't even know a rough height to give since the variance of units and coverage is so large. You'd have to play around or see what others with the same units do. In any case, getting lights in a good range for veg/flower reduce over all height issues and better node spacing.

You actually want the plant to stretch as natural as possible as it will hold it's health better. Just control the height with low stress net training and be careful not to have lights too close for light stress stunting. Don't reduce nitrogen and all those kinds of anti-stretch tactics. If you reduce stretch in such ways you will lose plant vigour or see deficiencies by week 5 or so. Pinching stems IMO is also too harsh a thing to do in stretch.

Can't say for sure, but plants seem to compete with each other in height if they are too close together. If not that, you won't have the room to net train so either way, have good spacing.

These external roots grew within the stretch period, it shows how much healthy growth the plant can do during this phase. You don't want to over stress or stunt the plant during this part.

1571953132361.jpeg
 
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rustyshaclkferd

Well-Known Member
seaweed, especially cold water seaweed like kelp, has a pgr (plant growth regulator) in it called cytokinin, that does exactly what you want, they are basically the opposite of auxins.
What this man said...internode length can be contrilled by hormone resposne or training techniques..lst, fim, mainlining...


also you can mechanically induce a plant response by bouncing the tops with your hand....

I know sounds dumb but when you continually bend the terminal node of a branch it has an effect similar to topping but less. It temporarily causes the plant to allocate more terminal growth hormones to dustribute more equally among lower branches. In effect arresting vertical growth for branching growth.

Heavy defaning of any lower canopy fan leaf to increase points of light. Also causing side branching.

Same as using multiple lights verses 1 1k light...more points of light , more atypical hormone displacement.

I wouldn't use b-nine or paclobutrazol based products or any growth regulators...clonex is bad enough these are systemic and have insane half lives in your plants tissue...

And are primarily designed and approved for horticulture..aka things you don't smoke and inhale ...normally.

Im sure their are safe versions with snaller half lifes. Ive heard of a grower usign a-rest.... im very skeptical
 
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PadawanWarrior

Well-Known Member
seaweed, especially cold water seaweed like kelp, has a pgr (plant growth regulator) in it called cytokinin, that does exactly what you want, they are basically the opposite of auxins.
That's a good summary of some techniques I've tried and validated through testing.

For the stretch period one thing it doesn't mention is managing the difference between veg kelvin and flowering kelvin. That is one of the biggest factors from what I've seen in testing. The greater the difference in colour/kelvin, the greater the stretch. In other words most stretch would be if you were vegging with 6500k and flowering with hps (2300k). So managing the stretch can be managed (greater or less) by choosing or forcing specific light colours during the first couple of weeks. An example to reduce stretch might be running a HID lamp with higher blue ratings during the stretch period, then switching it to hps. imo this is why you'll often hear folks flowering with hps, then switching to LED's for flowering seeing a big difference in reduced stretch under LED's. The most common LED kelvin rating is 3500k for flowering, so without changing veg light kelvin rating, flipping to hps in flowering vs. LED's will produce much more stretch, all other factors being equal. Prior to flowering with 3500k COBs I was using 315w CMH with a 3100k bulb and even with only a 400k difference there was a notable difference in stretch between CMH and COBs.

I can also vouch for negative DIF mentioned in the article suppressing stretch. Ran a couple of rounds last summer running negative DIF temps (higher temps during lights out) and saw a big reduction in stretch. I also noticed significant differences in bud output and density using this technique. It's difficult to run this during winter for me, but I'll go back to running negative DIF as the temps warm up, it was well worth the extra effort to maintain a negative DIF environment. If you want the stretch but want to try negative DIF, you can simply run the first couple of weeks in a traditional environment with say a 10-15F difference between lights-on and lights-off (lower temps), then switch the environment to negative DIF.

In veg, not sure why but those blurple multi-band cheap LED's (e.g. Vipar, or MARS) tend to grow very tight nodes in veg across multiple genetics and you don't have to do anything, they just grow that way under those lamps. I've used them for 4+ years and they go into flowering very tight, then I stretch them to open them up in flowering which gives me a great transition with benefits from both techs.
These guys sum it up better than I ever could. I use the negative DIF or close to negative DIF tactic and it works well for me to control stretch. I also feed them kelp, but didn't even know about the cytokinins and their effects with stretch. I'm glad I read up on negative DIF though, and have done it ever since I learned about it. And if I do want them to stretch more all I have to do is lower night temp, or I could feed them with cooler water which will make them stretch more too. I just thought these guys have awesome answers that a lot can learn from, I did.
 

rustyshaclkferd

Well-Known Member
The plant mechnaism in which type of light wave affects internode length, phototropism or phototropic response.

Watching it under time lapse footage is kinda hypnotic
 
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