Yra that's a huge beney right there,how involved is the process of raising brix ?
Hey 480, sorry this took so long. Life was really busy over the holidays.
Make a large pot of coffee before you read any further, this is a long post.
Ok, so brix is a measurement of sugars in a plant's sap. Leaf brix is what we are interested in measuring as growers, but sugars are in the entire plant, and plants can and do move them around.
Plants can sense a low pressure weather event approaching and will quickly move sugars from above ground to the roots, in case the approaching storm shears branches off, and that protects the energy needed to rebuild.
So if you take a brix reading and it's suddenly 4 or 5 brix less, check your weather app before you panic.
So to raise brix... Well in a nutshell all you need to do is increase photosynthesis (PS), but 1st lets summarize some things.
Plants, by natures design, take carbon dioxide from the air thru their stomata and turn it into sugar that can be stored for later use. Sugar gets turned into a product called adenosine triphosphate. ATP for short.
ATP is what is used as energy to power cells in pretty much all living things. Humans included. So plants create their own fuel.
Plants require a few things to do this. 1st, they require light as that's what drives
photosynthesis (PS). They also require minerals for proper cellular function, so let's assume that there is adequate light and minerals for this conversation.
After minerals and light, plants require 5 main components to produce sugars. They are the big pieces. They are Calcium (Ca), Oxygen (O2), Carbon (C), Phosphorus (P), and beneficial arobic soil microbes, and myco fungii is included, so when I say microbes I also mean myco fungii. The soil biota.
So plants produce sugar. With it they create energy to grow. In the presence of adequate light and minerals they will create sugars to their maximum ability if food and all 5 are available, and have the unique ability to create more energy than is required to produce that energy. A lot more. Over twice as much.
The food in the soil is created by microbes. They eat the dirt and poop it out in a manner that plants can digest it. It's called "fixing" and they can also "fix" nitrogen from the air and turn it into plant digestible nitrogen.
Microbes love carbon. They eat everything in the dirt to get it, so plant food is a happy accident of microbe poop as they eat the dirt to get the carbon.
Plants will take excess sugars created by PS and push it down and out their roots to feed the microbes to keep them healthy. In return they get poop from healthy robust microbes.
Those sugars that ooze out the roots are called exudates. So plants use their sugar profits to create exudates to aquire more food from the microbes. Now enter myco fungii.
It attaches itself into a special pore in a root and it collects the poop and moves it thru the soil to the root for the plant, as roots move very slowly, so it's more efficient to bring the food to the root than it is to bring the root to the food.
For this middleman service, myco is paid with sugar because myco lives underground and can't photosynthesize in the dark. Myco can move food very quickly. Myco must remain in control underground. It needs to be stronger than the microbes to do this. Hydrolysed fish fertilizer on a steady basis ensures that. It keeps myco healthy.
So this symbiotic system between microbes, myco, and a plant, creates enough sugars for everyone involved, but the system is only as good as the weakest link. If light and minerals are adequate then one of the 5 big pieces is the weakest link.
For a plant to get the right food at the right time all it does is tell myco, and myco will take the plant's root exudate and squirt it on the needed food source in the soil and microbes will gobble it up and poop out the required nutrient for myco to transfer back to the root.
If there are no weakest links then everyone gets more than enough to eat to become completely healthy, and now you have a healthy plant using healthy myco to get poop from healthy microbes. When all are fully fed, if there are no weakest links, there is left over profit that is stored in the soil. It's called carbon sequestering.
That occurs when high brix occurs. It's a plant's prime directive. Natures way. Plants are encoded in their DNA to strive to achieve this. High brix for healthy reproduction is all they are interested in, and they have tunnel vision locked onto it.
So a plant is happily rolling along and boom, it runs out of one of the big 5. The process is maxxed out. If that occurs when brix are 12 or less, plants know they haven't achieved high brix so they will call in the bug squad so they can be eaten to produce poop that their siblings can use to attempt becoming high brix. All they want is their DNA to move forward a generation and don't care if it's them or a sibling that does it, as long as someone does reach high brix to produce healthy seeds to perpetuate the family lineage. They will compost themselves to help their siblings.
So for us to grow a perfectly healthy plant in a pot we need light, microbes, and myco, minerals to function the cells, and food. Sugar pays the bills.
The big 5.
Calcium has many functions, it's not just food for a plant. It's electricity powers the soil as microbes, just like humans, run on electricity. It sets the soil's EC.
It also sets the charge in the soil to fluff it allowing space in the soil between the fluffed soil particles to let air and water move freely. That is called "tilth".
Air and water share the same space. Creating soil tilth is called "soil conditioning" so calcium is a nutrient and a soil conditioner. Any time you see a product that is touted as a conditioner, it means it helps create tilth.
It sets the stage for the process to work.
Oxygen, another part of the 5, is now readily available from good tilth at the roots. The microbes must attach an oxygen molecule to a food source in order for a plant to recognize it as food. No O2 molecule attached equals no entry into the root. Too much water displaces O2 in the rootball, causing no O2 attachment, and the plant starves even if there's food in the pot. That's how over watering kills plants. It starves them to death. Oxygen comes from atmosphere so it's free.
Carbon. Part 3.
It comes from CO2 in the air that plants pull in thru their stomata, and there is more than enough in the atmosphere to create high brix, but stomata are reactionary things, and if atmospheric conditions are less than optimal they will start to close, and carbon gets restricted. When VPD is correct for the stage of the plant's life that it's at, carbon intake is set correctly.
Part 4 is phosphorus.
It's the main ingredient in adenosine triphosphate (ATP) . It's very hard to mine but you don't need much. You do however need a smidge more today than you needed yesterday, and will need a smidge more yet again tomorrow. Some P is consumed, but the rest of it has the correct atomic charge to have food magnetically attached to it on it's way into the root, and it piggybacks other foods in.
The plant consumes some P to create ATP, and the rest goes round and round hauling food in and exudates out. The plant unloads the food from P, reloads it with exudates, the microbes unload the exudates and reload the food.
As the plant grows, it requires more food, and as the food needs go up, the microbe population will grow to provide more food, but the microbes now require more exudates to feed the larger herd, so as the plant grows more P is required to go round and round. You need more dump trucks on the road.
Microbes/fungii are part 5 and if you supply more exudates, they will come out of dormancy to increase herd populations.
Myco coordinates the dance.
So when calcium (part1) creates tilth, and water is correct, you get adequate oxygen (part 2), and if VPD is correct for stomata to provide adequate carbon (part 3) and Phosphorus (part 4) keeps slowly increasing for assimilation and hauling, the microbes (part 5) get more exudates to become healthier and more abundant, and can now load more dumptrucks. It all leads to increased PS.
Every lap of exudates creates a slightly larger and more robust system that can produce more exudates to make the next lap even better. Brix levels go up. The rich get richer.
When they get above 12 brix the plant is healthy, and will now NOT try to commit suicide by bug.
At 14 brix bugs won't eat any plant tissue, it becomes toxic and deadly to them as they don't have a pancreas, so they can't digest excess sugars, and the sugars will ferment inside the bug, alcohol is formed internally from the sugars as they ferment, and it kills the pest.
Pest know this and will avoid that plant.
So high brix is all about balancing the big 5 in the presence of adequate light to drive it all, and adequate minerals to provide everyone with proper healthy cellular function to do it all.
If you add sugars manually then the microbes ignore myco's instructions and eat what they want, not what the plant tells myco it needs, and the wrong poop is produced and it all crashes.
If you dump high P ferts in that are hydroponically available myco has P and will sever it's connection to the P miners, thus the plant needs to produce less exudates with less mouths to feed, and it all crashes. You can't bypass myco ever.
So it's about putting the right things in the soil in the beginning, and then maintaining calcium levels to hold the tilth so O2 isn't restricted, so the microbes can trade oxygen rich food for exudates and they do it with edible dump trucks made out of phosphorus. You need balance.
The bonus feature.
VPD controls stomata which regulate the flow of free carbon from the atmosphere. VPD is a 3-way formula of air temp, leaf temp, and RH. It works best when leaves are 2 degrees F lower than air temp.
Light levels can warm the leaf above what ambient air temps supply, so when you adjust your light until you have a perfect 2 degree offset in temps between air temp and leaf temp, you have set your light levels perfectly without a meter.
You can't just decide a PPFD level for your plants if you want proper photosynthetic rates, you must supply the right amount of light to be able to use what the root ball can provide, so too little light means you aren't getting the most out of your rootball, and too much light means you will photosynthesize too fast for the rootball and if the roots can't keep up, then a deficiency arises.
VPD is how everyone should be setting their light levels. The PPFD and DLI recommended charts have no idea how your rootball is performing, but when you adjust your light to get the 2 degree offset, light is in sync with the root ball. As the plant grows the root ball gets bigger, and more light can be used. VPD will tell you how much more.
The refractometer will keep calcium optimal, the water stik will keep oxygen optimal, use an IR thermometer to keep a 2 degree offset and the atmosphere will keep carbon and the rate of PS optimal, and myco will set up nitrogen fixing microbes to create all the nitrogen required, so if minerals are available then you just need to ensure P is adequate.
Put P in the pot at day 1 and the microbes will find it. It's really hard to add later without crashing everything.
So it's about balanced soil that is balanced to the atmosphere, and balanced light that is in the correct amount to match the abilities of the roots to provide adequate supplies from the soil.
Once the soil and it's biome are correct, VPD dials the pieces in to form the synergy.
Earth (soil) wind (atmosphere), fire (light) and water.
Easy peasy, limonene squeezy.
Hope that helps. Hydroponics bypasses all this. It's a backdoor hack into a secondary system that plants have so when spring floods occur they can eat the nutrient rich flood waters to get a boost in the spring. They don't get nute burn from it because they can only eat that water when PH drifts thru the sweet spot zone of 5.8-6.5.
That bypasses the soil biota, so it can't create brix very well and bugs are inevitable. The prettiest synthetic hydroponic plant on the planet is constantly trying to commit suicide.
Bug spray is your only real option. It's way more work for a lesser outcome than what brix can give you.
