Indoor Should i trim the leaves?

[Trifid]

Thinning, Leafing and LST - Pineapple Express
(An extract from https://www.autoflower.org/f44/perpetual-auto-grow-trifid-4591-12.html

The horticulturist should aim to produce plants with uniform growth, by moderation of internodal spacing and applying low stress/super-cropping and thinning techniques to achieve ample light penetration in both the superior and inferior canopies. Containers should ideally be rotated in the grow space periodically to ensure light exposure and stimulate phototropism. White quartz/marble chippings may be implemented to reflect light from the surface of the growing media serving to enhance light exposure and intensity.

Hybrids that display changes in apical dominance have a tendency to distribute their floral productivity to the lateral colas as they compete against each other for secondary dominance. Competition leads to the shading of inferior budding sites via the continued development of accessory and fan leaves that serve to provide an energy surplus to the terminal bud sites. Leaves have a definite function in the growth and development of plants, but excessive foliage from lateral branching may lead to a lack of light penetration of the lower canopy with pheno-types that exhibit short-stocky profiles.

Pineapple Express (Day 62) - Prior to thinning and leafing

Since cannabinoid resin and floral productivity are influenced predominantly by light intensity (in particular UV-B rays), one may choose to trim selectively the leaflets responsible for shading and conserve the remaining leaf mass. This process called ‘leafing’ serves to reveal lower and inferior bud sites to enhance resin productivity and floral development in these plants and moderate localized humidity and air flow without severely compromising the energy surplus provided by the leaf mass. Other techniques for maximizing light exposure to hidden bud sites attached to the lateral branches include bending and super-cropping which may be performed at various stages during the vegetative and flowering periods. Care is taken to prevent tissue and stem damage when performing LST to minimize recover time.

Pineapple Express (Day 62) - Undergoing thinning/LST techniques to expose and 'spread'
lower canopy to reveal hidden bud sites

One of the biggest mis-conceptions in common cultivation practice arises from the grower’s assertion that large shade leaves subtract or draw energy from the flowering plant. It is often assumed that by removing these leaves, surplus energy will be available and large floral clusters will be formed, but in fact the opposite is true.

Never-the-less, excessive foliage development in short-stocky phenotypes and high producing sativa hybrids may also inhibit to some extent, the development and maturity of inferior and hidden bud sites - shading the inner portions of the plant, leads to immature, atrophied floral clusters in the lower canopies. These sites may be removed early in flowering to effect cytokinin translocation which serves to induce ‘stretching’ or lengthening of the internodal spaces. This has the effect of raising the height of the superior canopy enabling the terminal buds to enhance their light exposure as they compete for dominance.

Pineapple Express (Day 62) - Leaf pruning to expose the lateral colas;
only the leaflets directly above bud termini are removed

In the case where these sites have been conserved with the intention of them going into maturity at the right time, thinning and leafing techniques are more of less essential to ensure these sites mature in-concert with the superior canopy.

Pineapple Express (Day 69) - Stage 2 LST to spread lower canopy

Caution must be taken however to ensure no more then 20% of the foliage is removed at any one time since excessive leafing can lead to de-hydration of the plant tissues, may interfere with metabolic processes and in some cases may induce senesence. Rather, small quantities of obstructing foliage is removed periodically throughout to ensure uniform growth of the budding sites. Correct and selective thinning adds aesthetic qualities to the grow space and assists in improving humidity levels and air-flow leading to improved productivity.

Pineapple Express (Day 75) - Swelling of revealed lateral colas

Pineapple Express (Day 77)

 

[UHF]

:thumbs:Awesome info Trifid
It well sure help me on future grows.

 

[Trifid]

No problem glad i could contribute here. This is by no means everyone's interpretation but i see this method as synonymous to the Big Bad Wolf's intelligent design of said porridge (not too hot and not too cold, but just right..) in the famous nursery-rhyme. This is in the sense that we are not removing the value of the leaf entirely but we're not ignoring the problem of excessive foliage either. I see value in both of the classical interpretations of dealing with shade leaves, but for me the right technique lies somewhat in the middle

 

[micro.grower]

Trifid, I Totally agree with you. I have even removed petals off of leaves that were blocking lower sites. Like you mentioned, it must be done in moderation. Thanks for putting the scientific explanation out there.

 

[nineweeks]

Excellent information and entirely true Trifid. Reminded me of horticulture text books when I took it as a subject at school. I panicked a week ago after I removed a lot of foliage but I need not have worried, I just did what I always do with many plants, be that deadheading (removal of decaying flowers) or removal of leaves to allow more light.

I guarantee you that Chateau Mouton Rothschild remove leaves (plucking) to allow more light exposure to ripening berries. That is why grapes are opened up on a trellis to allow this even bud height and as the berries ripen leaves are periodically removed, however leaves must remain covering part of the berries to prevent sunburn, as the sun moves over the sky the remaining leaves shade different parts of the berries at different times of the day preventing sunburn. I am using my knowledge of growing grapes and applying it to weed and treating my buds as I would grapes, training them to the position that allows maximum light exposure and removing some of the leaves that are blocking ripening buds It would be very easy to remove too many leaves though, I thought I did but I feel I just got away with it this time. I will be a little more careful this time and not so heavy handed

 

[Muddy]

Great discussion and thanks Trifid for much useful information. This begs another question. Should small buds in close to the main stem be removed? It's always been my feeling that since those buds always remain small and usually don't fully mature, they should be removed. Does removing them actually promote better growth in the bud sites farther up the branch?

 

[Trifid]

Should small buds in close to the main stem be removed? It's always been my feeling that since those buds always remain small and usually don't fully mature, they should be removed. Does removing them actually promote better growth in the bud sites farther up the branch?

For sure.. This is a good question that deserves some consideration, especially when budding sites become diffuse in sativa dominant profiles. This relates to what has been briefly mentioned in the thinning guide..

-Excessive foliage development in short-compact phenotypes may also inhibit to some extent, the development and maturity of inferior and 'hidden' bud sites - shading the inner portions of the plant leads to immature, atrophied floral clusters in the lower canopies. These sites may be selectively removed early in flowering to effect cytokinin translocation to the distal axillary sites. This serves to increase the floral mass productivity at the bud termini by the translocation of energy surplus and induces lengthening (bolting) of their internodal spaces. This has the effect of raising the height of the superior canopy enabling the terminal buds to enhance their light exposure as they compete for dominance with the apical terminus - this is the principal hypothesis of micro-cultivation techniques (SCROG) for maximizing crop productivity.. Alternatively, some may prefer to conserve these inferior sites as a potential for a secondary harvest.

 

[dykster]

Concerning topping....It depends on the strain and structure of the plant. But at first, I would just grow your auto in it's natural state first to see what it does. Most of the time my autos grow in their natural state although I have some tall autos that I top because they get too tall for my grow situtation. Hope that helps.