Low Stress Training (LST)
Jag hittade inget inlägg här på swecan om LST så jag postar en liten sammanställning som jag gjort. Jag har inte så bra koll på källorna men jag vet att det mesta är cut’n’paste ifrån vad Delta skrev och sedan är det nog något som är saxar ifrån overgrow också.
Jag har själv aldrig testat LST (så som det är beskrivet här) så jag har inte kunnat vara kritisk till materialet. Det är möjligt att jag pga av min okunskap feltolkat källorna också
Tyvär är det på engelska, men jag orkar verkligen inte översätta det till svenska så jag hoppas att det går bra i alla fall :oops:.
edit: Nu har jag testat LST och det fungerade bra för mig. Det resultat jag fick får mig att tro att LST säkert kan vara bättre än SCROG, men jag har inte gjort en vetenskaplig undersökning så det är mer en magkänsla.
Low Stress Training (LST)
Rightly performed low stress training (LST) doesn’t stress the plant instead it should improve plant overall by reducing stress and present natural tropisms in a greenhouse. Other objectives are to maintain an even canopy and efficiently use available space. The main goal is of course maximizing the yield.
The Reason for LST Being One of the Best Techniques
All though there exists a number of different growing and training techniques, LST is considered one of the best.
Supercropping vs. LST
When you combine the LST with pruning techniques you got supercropping, which is/was a popular technique. However pruning techniques such as topping or FIMing stresses that plant, which delays the harvest. So supercropping/pruning is a very bad idea since that will counteract the beneficial effects of LST.
SOG and SCROG vs. LST
Tightly packed leaves ruin the airflow, and a good airflow is a critical environmental factor for a good yield. In LST you use the space you have to provide the plant with the space it needs instead of cramming it all under a screen as with SCROG or tightly packing canopy’s side by as done in SOG.
How to do LST
This is how you do LST. Remember that the earlier you start, the more pronounced the effects will be. Preferably you read the following sections in the same order as they are presented here,
When to Start Training
Training too young can uproot the plant because the root system isn’t deep enough to sustain much more than a fan blowing on it (constantly). How early is too early? If the plant comes ripping out of the medium, it’s too early. You might wait until the plant is a little bigger than 4″ to start training. Not necessarily, though. It depends on how vigorous the plant is or more actually, how healthy and large the root system is. Once you are sure that it can handle the training, you could begin.
How late is too late? If your branches snap when you bend them, it’s too late (or you bent it too far). Training too late into full flower can break stems because they become woody and considerably less pliable. An additional side-effect of hardened branches and stems is that pulling too hard on the top of the plant can tear the roots and shock the plant. The plant could get woody before even putting them into flowering; and that is all about the auxin:cytokinin ratio. if you’re interested in a more techincal why.
Training for Adventitious Roots
This is an important topic to training that deserves more than a honorable mention and more roots is the objective!
Positioning the Apical Meristem
First of all the plant should be transplanted and put down into the dirt in a 45 degree angle. This serves two purposes. One reason is that the plant is leaning already making it more suitable for training purposes and the other reason it that if the meristem gets close enough to the medium to grow new tap roots. One single vertical growing apical can only support one single tap root, but when the meristem is positioned somewhat in an angel, more root taps will grow out. The added roots are needed for a large plant and maximum yield. A plant that is trained horizontal or leaning sharply so that all shoots can translocate from other parts of the plant because they share the same root network which makes the plant more stress resistant,
Remember that it is easier to manage the main stem if it is offset from the center of the bucket. This will allow you to tie it down across the rim of the bucket and let you pack those grow shoots together very tightly.
Positioning the Apical
Since cannabis can produce adventitious roots another great way of getting more roots is to running more of the apical closer to the dirt. The apical will put roots out all along the stem if it is encouraged.
Training the Branches by Bending and Tying Down
Training should be started out during vegetation using techniques such as bending and tying down.
Plants naturally bend towards the light. They do this for their benefit, trying to better get into position to receive more light. Why wait for plants to evolve, use your smarts to bend plants into positions that are beneficial. Bending the tip of a branch over into a position where there’s no vegetation will speed growth for 2 reasons: First the branch tip you moved is now getting more unobstructed light by moving it to an area free of vegetation. Second, the area you moved the branch away from is also receiving more light than before. So those parts of the plant also benefit from the move. Potential for growth is increased.
Forceful confinement or the use of string, twist-ties or a brace of some kind may be required to keep bent branches from simply growing back to their original position. Massage the bending point of the branch with the fingers of one hand while slowly bending; only intuition will tell you when you’ve reached the breaking point. Some branches don’t have a breaking point, you can tie them in a knot a they’ll still grow. Others will snap as soon as you try to bend them. It will take practice and a few broken branches before you learn how far, if at all, any given branch can be manipulated.
When you have bent the branch downwards, a new branch will begin to grow from the highest point of the bent branch. Just ‘spreading’ them doesn’t work as well as actually tying them down, because when the tops are bent over, it causes a hormone in the plant to be released. This only happens if the top is tied lower then the highest point on the branch. So always tie at least at 90 degrees because if you don’t pull it over far enough, the side branches won’t fill out.
How to Position the Branches
The meristems are relative both below and above ground. Every branch above ground has a corresponding root that will (in a way) mimic it’s ‘significant other’ branch above ground. So, from a training perspective, if you bend a branch TOO far over the side of the container, without eventually returning it to a position over the container (the S), the mimic root will run into a wall and forced down. If the plant grows too tall, or too dense, the roots may become bound and certainly, salt buildup occurs at an alarming rate. Therefore it is recommended that you keep the plant trained within the constraints of the container. For example, if you have a 5 gallon paint bucket, your plant on top (without leaves) should be roughly the equivalent (without leaves) of another paint bucket stacked on top of the original.
One way to easily go about the training of the branches it by forming an ‘S’ type meristem over the container. This produces more branches and makes a shorter plant.
Training for an Even Canopy
It’s all about the canopy you are creating. It may be more art than science. Practice does make perfect. The main objective is to create an even canopy. Please notice that if cola’s get too close together it promotes mold and other unhealthy consequences such as reducing the airflow. The foundation for canopy is actually laid during vegetation and early flowering, and if you want an even canopy you should keep this in mind when you start to train your young plant. During preflower and stretch the pressure from the anchors can be released completely to let certain branches catch up with others.
Anchors should be removed the last few weeks of flower. By this time the plants have adapted to their new form and shouldn’t revert back. If they start too, it’s still stretching and it could actually be a variety of factors causing this. Tie it back down and evaluate the overall health of the plant.
In late flowering you would also want to get rid of all growth 3-4 inches from the top of the soil. This will promote top growth and these little shoots will clog airflow under the plant which could be leading to mold and mildew under the canopy.
When the branch gets bend too far, it crushes. You can repair this damage by cutting a drinking straw to fit the broken part. Slit down the middle and put it on the branch like a splint. Don’t try anchoring that branch for about 2 weeks until it heals. You could also use some tape or something to splint it with, what is important here is that you take the weight off the wound.
Increased Growth Rate
Along with LST comes increased growth. Because of the heightened production of the cytokinin hormones, thick stems (auxin:cytokinin balance), and over all power growth, the fertilization and irrigation schedule and EC becomes a whole new game. The plants metabolism is hyped due to the tropisms and stretching can be a resulting side effect. This is actually due to deficiencies in the Potassium, Calcium, and Sulfur levels required to sustain optimal health and power growth.
There is such a thing as over-training. Bending branches, repeatedly, can deplete a plant of its natural supplies of the auxin hormones (this isn’t good if you do not supply with extra biostimulants).