Experts: What Happens If...

[robd1017]

This may be a simple question but I haven't seen it comprehensively answered anywhere. Exactly how does each branch use the light it absorbs from the leaves attached to it? If I leave a side branch on a main stem but top all new growth on that side branch, will the light collected from those fan leaves on that side branch feed the growth on the main branch (especially buds), or will it simply make the stem on that side branch thicker? Even if it does make the side branch thicker instead of the main branch, does the side branch use more energy than it produces from its own leaves, thereby draining energy from the main stem (and buds)? Do the answers hold true for both sativa and indica?

I understand that most people remove all side branches but has there actually been any scientific studies (or side-by-side grows) that definitively show exactly what happens when you remove the branches versus when you leave them on but remove all new growth? If not, I'll conduct my own experiments but it'll obviously take years to get enough data to draw a valid conclusion. Leaving more fan leaves on the plant would make more energy available for the buds (assuming you're properly shaping your plants to maximize yield, as in a SCROG), but only if those side branches produce more energy than they consume.

Thanks for reading.

 

[GT21]

This may be a simple question but I haven't seen it comprehensively answered anywhere. Exactly how does each branch use the light it absorbs from the leaves attached to it? If I leave a side branch on a main stem but top all new growth on that side branch, will the light collected from those fan leaves on that side branch feed the growth on the main branch (especially buds), or will it simply make the stem on that side branch thicker? Even if it does make the side branch thicker instead of the main branch, does the side branch use more energy than it produces from its own leaves, thereby draining energy from the main stem (and buds)? Do the answers hold true for both sativa and indica?

I understand that most people remove all side branches but has there actually been any scientific studies (or side-by-side grows) that definitively show exactly what happens when you remove the branches versus when you leave them on but remove all new growth? If not, I'll conduct my own experiments but it'll obviously take years to get enough data to draw a valid conclusion. Leaving more fan leaves on the plant would make more energy available for the buds (assuming you're properly shaping your plants to maximize yield, as in a SCROG), but only if those side branches produce more energy than they consume.

Thanks for reading.

Its not just about energy.. it has to do with plant growth auxins (cell elongation)
When you top a plant you stop the auxins and it diverts to the side branches. Works for both sat and ind... im not really sure what youre asking though....

 

[robd1017]

This is essentially a very specific question about how pruning affects growth (and eventually yield). For example, in a SCROG grow, the goal is to fill your space with a field of buds that are all the same height and therefore all the same distance from the light. Theoretically, you could prune your plants to have, e.g., 32 bud sites or 16 bud sites and the final yield would be the same (assuming you had maximum leaf coverage in both instances), you'd simply have a larger quantity of smaller buds with the 32-top set-up than you would with the 16, at least that is my understanding. However, larger buds are said to be more desirable because there's less trimming work after harvest.

So when you're pruning your plants for SCROG to maximize leaf coverage/absorb all available light but also trying to reduce the number of bud sites to make for an easier harvest, you run into this issue: If you completely remove an entire side branch (as most people seem to be doing with lolipopping and mainlining), you then create a hole in your canopy where light passes through to the floor and is therefore wasted. Of course you could simply veg for several more weeks to try to fill in your canopy, but what if you had left that side branch intact with all of its fan leaves but simply removed all new growth that would otherwise turn into a top or bud site, those fan leaves would be collecting all available light and sending that energy to your chosen bud sites - unless that side branch actually uses more energy than its fan leaves produce, in which case leaving that side branch on would actually REDUCE yield because it's taking available energy away from the buds.

Which brings us back to my original question: Do the side branches use more energy than they produce if you're constantly removing all new growth from them? Do they feed the remaining tops and produce bigger yields? I know that most people prune heavily, but is there any actual scientific basis for doing so if you've already shaped your plants to maximize yield in a SCROG? In this age of alternative facts and fake news, scientific evidence is the only thing we can trust. ;)

PS - I'll post photos of my first grow after I get home. 4x4 tent with 3 Chocolope sativas in full glorious SCROG, autopots + coco. Second week of 12-12 and everything's healthy as can be.

 

[DrMcSkunkins]

Think of your plants stems as a highway, the nutrients and water travel along the highway to their final destination, the bud parking lots. The more parking lots their are along the highway the less traffic there will be reaching the top buds. If you leave all of the larfy undergrowth on then alot of the nutrients are used before they reach the top. The fan leaves are like solar panels that catch and store light energy and carbon dioxide and store it for use in photosynthesis and building of plant materials.

 

[dnewsome2]

This may be a simple question but I haven't seen it comprehensively answered anywhere. Exactly how does each branch use the light it absorbs from the leaves attached to it? If I leave a side branch on a main stem but top all new growth on that side branch, will the light collected from those fan leaves on that side branch feed the growth on the main branch (especially buds), or will it simply make the stem on that side branch thicker? Even if it does make the side branch thicker instead of the main branch, does the side branch use more energy than it produces from its own leaves, thereby draining energy from the main stem (and buds)? Do the answers hold true for both sativa and indica?

I understand that most people remove all side branches but has there actually been any scientific studies (or side-by-side grows) that definitively show exactly what happens when you remove the branches versus when you leave them on but remove all new growth? If not, I'll conduct my own experiments but it'll obviously take years to get enough data to draw a valid conclusion. Leaving more fan leaves on the plant would make more energy available for the buds (assuming you're properly shaping your plants to maximize yield, as in a SCROG), but only if those side branches produce more energy than they consume.

Thanks for reading.

Everything underneath what you top will grow bigger. Bigger stems can grow larger bud.

 

[dnewsome2]

I would never top my plant during flower.

 

[Shawnery]

I just read something that stated a fan leaf inly has so much ability to achieve the process and once new leaves start growing you should be removing the oldest ones. They start to lose their effectiveness with age and start to use more energy than they produce. I couldn't find a precise age but you get the point.