Defoliation - When and how?

DrGhard

Well-Known Member
I think we have sufficiently beat the defoliation debate to death. Kind of saw that one coming. Consensus? do whatever you want, they are your plants. I guess there is a time and place for everything. Maybe the message is that the more your grow varies from "natural" conditions.. i.e one plant per 8 square feet outdoors, the more you may benefit from these techniques that are not necessarily covered in the literature.

But anyways, since a few are flexing their botanical knowledge muscles, I do have a question that requires some knowledge to answer. It gets back to this fundamental practice that I see LOTS of people employing and rationalize under botanical principals that don't make a whole lot of sense.

What I am referring to is the dumping of shit loads of sugar in their watering solutions. Some have this notion that if we "give them sugars" then they won't have to make them and they will spend all their energy forming flowers. Others claim the feeding of fungus and other biologicals in the rhizosphere.

Here is what I do know:
1. Sugar is produced in the leaves and transported (primarily) to the roots via phloem. 2. The primary mechanism is both differences in turgor pressure and concentration gradients between sources (leaves) and sinks (roots). If you are lost already then read here: http://www.ars.usda.gov/is/AR/archive/mar99/sugar0399.htm or here http://www.sciencedaily.com/releases/2007/12/071221163216.htm
(please note that these processes have just been proven in the last ten years)
3. Plants have a VERY limited ability to absorb sugars in their roots due to the presence of the casparian strip.

For this reason, I typically foliar feed sugars as leaves don't have a casparian strip.

Ok, so here is the question (fucking finally): Does the presence of high amounts of sugar in the rhizosphere actually serve to DECREASE uptake and dispersal to flowers?

My thinking is that because plants transport sugars from the roots via the xylem through the mechanism of transpiration (which is driven by osmosis and not active transport (like sugars into the ). Wouldn't the increased salinity of the rhizosphere from adding shit fuck loads of sugars actually serve to hinder uptake and transpiration due to a lower concentration gradient or is it not that sensitive. I mean, I haven't seen plants wilt from sugar introduction but I run the plants hot and dry during flower and need to maximize the ability for transpiration (and thus nutrient and sugar transport to flowers).

I'm basically trying to decide if I should bother adding any sugar at all in the rez. yeah, feeding biologicals is always nice but the roots exude sugars for them to eat (that's how the exist in nature as, in least in my area, it doesn't rain sugar water).

sorry to necro an old post in an old thread, but i figured i could share my knowledge since the topic is of interest to many people. having sugar in the nutrient solution is NOT beneficial to the plants.
as mentioned already the sugar is not optimally absorbed through the roots, and it actually makes the osmolarity of the nutrient solution higher. this means plants have harder time absorbing the other nutrients. for this reason sugar solutions can be used for a cheap flushing solution (although i wouldnt recommand it, see below).

in addition sugar in your nutrient solution higly increases the risk of contamination by detrimental microbes, which can very easily feed on the excess sugar in the solution
 

Grandpa GreenJeans

Well-Known Member
Don't defoliate
yes and no,
there is an appropriate time to defoliate and during the active flower developmental stages its not appropriate. Id be inclined to defoliate in the last week during ripening as the need for photosynthesis and the conversion of carbohydrates isn't a high priority and most rely on a plant to cannibalize itself to properly rid the vascular and leaf tissue of stores nutrient. If ignored, the buds burn harsh and terpenes are a lack there of. Your harvest will smell of grass or hay, and that's the chlorophyll.

Reduce the solar panel/ nutrient reserves (fan leaves), and you can that much quicker rid the plant of internal nutrient reserve.
 

benbud89

Well-Known Member
I am REALLY beginning to question the "common sense" approach that cutting of leaves is bad becasue obviously plants use their leaves for energy production.

It seems that many monoecious plants can actually stimulate flower and seed production in response to defoliation...
http://www.ncbi.nlm.nih.gov/pubmed/20519239
http://www.jstor.org/pss/2389881

obviously plant response varies by species but there are definitely some trends that make sense in an evolutionary pressure sense.
common sense is the least common of all the senses.
 

soulazz

Active Member
Duuude, i've read so much bullshit I decided to post.

1) You can defoliate whenever you want
2) It is bad.
3) You are wasting energy. Even when leaves get no light they still have stored energy and the plant will use it when needed.
4) Buds can't get energy and need leaves to develop.
5) Humidity, mold, and stuff related to high humidity can be treated with various other methods.
6) One possible scenario to cut a fan leaf off would be when it is shading an area that is larger then it would be if the leaf was not there. I mean, if the area being illuminated is higher then it is with the fan leaf, cut it.
7) Bare in mind that every leaf you cut is a little more time for your harvest. At least for a big bud harvest.

Tchau, do Brazil! =)
 
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