Got a sick plant? Ill help

Hello Grasscity!


I've been wanting to do this for a while and with the season at an end I don't see why I should wait any longer. I've found in my years of growing marijuana that my best research was through diagnosing problems in my garden and in an effort to continue with that mentality I'd like to open a thread for diagnosing common/intricate problems found in both indoor and outdoor cultivation, organic and chemical chelates. Where I'd like to see this thread shine is in the cited, well founded content as opposed to the myths/common misconceptions that plague the net.

With that being said, please be respectful above all else..it's hard to learn with a poor attitude and no one moves forward. Pics are encouraged and of course detailed, thorough data collected over a moderate duration. A good place to start would be environmental conditions ( Temperature, Relative Humidity (RH), Incoming / Outgoing air exchange along with static fans) growing medium (Soilless such as coco coir or peatmoss, DTW, DWC, Aero, Organic Soil) water quality (Ph, Hardness (PPM)), chemical nutrient regiment (Heavy 16, Canna, etc.), pest control (chemical pesticides such as myclobutanil or organically derived pesticides such as Azamax).


I'm eager to share and learn! Lets get to it

 

Howdy NaturalMistik! Calcium and magnesium balance can be a true pain in the ass, something I've definitely seen in my garden before and I was able to fix it after a couple things;


1. Water quality; I've found most ca/mg deficiencies occur when using poor or less than ideal water. Water hardness is a scale of the mineral content and measured in parts per million. Rule of thumb for cannabis cultivation is roughly 150 ppm, but certain strains will require/more less (Indica's seem to favor a little higher, sativas a little less because of the balance with increased potassium). If your water hardness is too high and you're supplementing then that's the first correction to make. I will say that RO water is never the answer, its ph instability and zero buffer provide for some pretty wonky readings in the rez. I opt for 50/50 RO to tap if I have to lower the hardness. Essentially with this you're providing too much calcium and either locking out magnesium OR locking out potassium resulting in poor transportation and an oversaturated medium.


2. VPD or vapor pressure deficit. This is the 'balance' between your temperature and relative humidity. You sir have whats known as a high vpd, probably 1.5 kpa or higher (.85 kpa is the 'standard' for ideal plant growth, if that counts for anything). This means that your plants aren't able to 'sweat' as much since the surrounding air is holding too much humidity and unable to take on anymore. Make sense? When you have a problem like this, you're creating both a deficiency in the plant and imbalance in the elemental exchange between potassium, calcium, and magnesium (Primarily because of an excess amount of potassium remaining in the medium).


with all of that being said...you're lady honestly just looks a little hungry (When you have a high vpd you need to feed at a higher ppm since the plant is not 'drawing in' as much due to its inability to sweat. Feed less with a low VPD to avoid overfertilization since it's going to be drawing in more due to its ability to sweat more.)\\. Perhaps some more details on your water quality and nutrient regiment (PPM's are a MUCH MUCH MUCH better way to measure your feed as opposed to a volume measurement) and we'll be able to get ya straight .

 

/chestbump lol. If your water is stable, I'd say up the feed and you could always tinker with dropping the ph (Might start around 5.5) to increase Ca availability and see what happens. One thing at a time though.

 

VPD and turgidity correlate as a visual sign to a healthy plant. 'Praying' leaves show max transportation and evaporation on the leaf surface; https://en.wikipedia.org/wiki/Turgor_pressure

 

.85 Kpa = 75F and 58% RH in my veg room


http://autogrow.com/downloads/download-software-an...
VPD spreadsheet is the 3rd link

 

Hey whats up man, grats on starting up your first garden! I'm sure the spinosad was effective against the thrips, but I would definitely advise continuing applications plus neem and silica foliars . When treating pests, you have to effectively kill 3 stages; eggs, juveniles, and adults so using multiple products designed for each stage is best. What I'm seeing looks a micro deficiency as the cells are unable to divide appropriately, causing the tear. I've definitely seen it before, also seen the tips start to literally grow laterally as opposed to 'out', I can see yours starting it too.


Your method is more than do-able, but not quite ideal. You have a good bagged soil which will sustain the plant for 30-45 days r roughly from what I've seen. The problem is after the mediums been zapped and you start the bottles theres no calcium carbonate remaining to balance the Ph. I know gh makes an organic bottle thats cal/mag carbonate aka Lime mixed with a sugar to aid decomposition and make it available a little faster. Even still after using your bottles, they're going to need to be broken and made bioavailable by the soil bacteria, this will take 2-3 weeks roughly to take affect so you have to sort of be premeditative. In organics, Ph is somewhat irrelevant as we rely on the science behind liming and the leeching of hydrogen to stabilize our Ph, so assuming you have the calcim carbonate available then your Ph pen is not needed and ph balancing your feed is actually counter productive.


So, to solve your problem; I would get a bag of powdered dolomite lime and garden gypsum dust. Top dress each container with 1tbls per gallon and add a nice 2'' layer of quality compost or earthworm castings. Water and walk away. Observe for 2 weeks and if the problem corrects itself then continue with the bottles not including cal/mag. Continue for another 2 weeks then maybe start working in the cal/mag bottle as the extra calcium will be needed early flower . Remember with organic bottles you need to be premeditative..

 

There is no need to adjust the ph of the feed as it its neutralized by the carbonate in the medium no matter what