Various plant issues - Ace Malawi, Panama x Bangi Haze, Thai Chi

[Subu]

Hi all,

Background information:

• All plants are in week 4 day 5 of flowering (flipped on day 25 after sprouting so approx 58 days old total).
• Training methods: topped after 4th node a week before flipping, SCROG.
• Medium: Organic soil containing upgraded black peat, granulated peat moss and perlite.
• Nutrients: organic nutrients from the same manufacturer as my soil. Note: my nutrients don't contain any calcium or magnesium. I continued to feed all plants with veg nutrients for the first 3 weeks of flower, then went to water only and have since given about 2 feeds with the flowering nutrients in the last week. Nutrients have always been diluted at 0.25x or 0.5x strength.
• Growing in a 4x4 tent in 5gal pots, with a 450w 2.7 umol high quality LED running at approx. 400w with 65-70cm distance from plants.
• My two Malawi plants got minor nutrient burn about 2 weeks ago which isn't related to any of the issues in this topic. Other plants could handle more nutrients.

Temperature currently constant around 21-23C with ~55% RH (I can increase the room temperature if needed, it seemed like they were growing fine even on 20-21C).
Watering habits: generally watering every 2-3 days, I have definitely overwatered the Malawi (potentially several times when it was younger) and Panama x Bangi Haze (only once which was recently but the apparent nutrient issue already existed). Water is PH'd every water/feed to around 6.2-6.5 using an electronic PH reader.


Issues:

Malawi

I am currently growing two Malawi plants and this one seems like it was a runt from the get go but I decided to keep it. I definitely watered it too much when it was young which may have caused its issues.

Symptoms: leaves are dry and papery to touch, took ~2-3 weeks longer than other plants to show sex in flowering, growing significantly slower and is about 30-40% smaller than my other Malawi which is doing very well and is vigorous.



Panama x Bangi Haze

Lower leaves yellowing and dying (symptoms for 7-10 days, got much worse recently). Multiple leaves have already curled up and died. The issue is quickly spreading to near flowering branches as it works its way up.




Thai Chi

Lower leaves significantly yellowing (got a lot worse in the last few days), possibly experiencing the same deficiency as the Panama x Bangi Haze?

Note: It appears the yellowing of lower leaves is also affecting my healthy Malawi and Purple Haze plants (not pictured) but at a much slower rate.


I already tried to do my own research and figure this out but I'm torn between a few different potential nutrient deficiencies and it's now become urgent to get this fixed. Thanks

 

[Tangwena]

If they were mine I would def be thinking not enough nutes if they were green and healthy on the vedging nutes the flowering nutes are too weak.
I have grown Aces Panama and Malawi and they like nutes and are very easy to grow your probably under feeding them.
Some CalMag probably wouldn't hurt either I also use LEDs but I grow in coco and never have nute issues with those strains if anything they seem hungry.

 

[Dr Bombay]

Hello Subu,

Nice set-up and l feel you wanting to get these beautiful plants on track.

I am almost a novice at this. So...

I grew my first tent with a number of different ACE strains. I also grew in soil. I used dry nutrients.

Things that helped me when l faced a similar situation.

I used worm castings to give the plants nutrients right away and evaluated my setup.

Seems like you are by the book with regard to setup.

The other thing l did was back off my lights to 50 percent. I have bar style 480 watt. Upped it to 75 percent for last 4-6 weeks of flower. I found the LEDs really caused the plants stress.

I was able to bring in harvest.

It's hard to know for sure with so many variables to consider.

The worm castings are a safe bet to provide nutrients and buy evaluation time.

There are incredible growers on this site that would be able to provide better intel.

Best of luck with these. Looking forward to seeing these plants take off!

 

[bsgospel]

Why do you dilute your nutrient strength? Do you know the EC of your feed? What meter are you using?

What's the NPK of your feed? Which manufacturer? Why no calcium?

 

[FletchF.Fletch]

Do a watering with just some Cal/Mag (1ml per litre) and a pinch of Epsom. Water to runoff and check your ph and EC values. The signs can be similar for both over and underfeeding. Testing the values of your runoff Will give you your answer. If you don't have an EC meter, you should get one. A cheap one is fine. Just testing runoff ph will tell you some of the story, an Acidic ph reading means nutes have concentrated in your soil.

 

[troutman]

^^^

Cal/Mag will help. I'm using some now and it really made my plants get green again.
I'm also using LED's and I think increased nutrients is a must under them. Increase
your feeding a little each time until the plants catch up. If you use too much you may
burn them and that sucks.

 

[therevverend]

I agree with the other posters, your problem is nutrient deficiency. In flowering lower leaves will naturally turn yellow and die as the plant uses up the nutrients in them. As a plant ages the fan leaves are where they store their nutrients and energy. Kind of like a hump on a camel. This is exacerbated by them being underfed on N in Veg, they're using them up a little faster then you'd like. At this point it's too late to give them N, it's counter-productive in flowering. A little bit as part of an N-P-K mix would be fine, I'll explain about this further down. Novice growers often make one of two mistakes, either stripping all the fan leaves while they're still green or panicking when the fan leaves turn yellow or red or purple. I don't want to get into a big debate about 'flushing' but this is what is happening to your plants. You want them to basically run out of N by the end of flowering. Except that you're maybe a week or two ahead of schedule on running low.

Do you see the weird variagated coloring on some of the leaves? Sort of a yellow/green zebra pattern? (magnesium deficiency) Along with yellow leaves with bright green veins? This shows your Calcium-Mag-K (potassium) are deficient. The most important is potassium because it's critical for proper flowering. You also need Phosphate. These are the primary flowering nutrients. I'd give them nutrients with maybe a 0.5-4-3 type ratio. (N-P-K) A little molasses would help, it would supply a bit of N and might take care of your cal and mag problems. Be sure to read the labels, at this point you don't want to feed them too much. You need the Cal-Mag from somewhere, epsom salts, molasses, Cal-Mag supplement, there's a variety of sources both organic and inorganic depending on your style. I'd give them both a dose of molasses and epsom salts, along with a good bloom mix, even better if it contained a little bit of calcium.

You don't have a lot of time left, you're at the point that I start cutting back on fertilizer. As your plants go into late flowering they need less and less. The last two weeks I go straight water. These ace strains use more nutrients because they've been bred for indoor growing, usually these equatorial landrace types need very little and it's easy to overdo it. So you don't have to be as cautious. I'd immediately hit them with a strong dose, wait 3 or 4 days to see how they react. Then you can adjust, go with one more strong if they need it. From there I'd go medium-medium-weak-weak. When they're past 6 weeks they don't need much. I believe they take 11-14 weeks, I'd play it by ear but I'd probably go straight water after 8 or 9 weeks. Especially if they lose the deficient look.

 

[RED 1]

Why do bags/pots look so brand new at this stage?

 

[Creeperpark]

Your plants are hungry and need to be fed, however, make sure you cut the nitrogen since she's flowering. Get yourself an EC or TDS meter and test the run-off so you will know what you are doing.

 

[Switcher56]

Your plants are hungry and need to be fed, however, make sure you cut the nitrogen since she's flowering. Get yourself an EC or TDS meter and test the run-off so you will know what you are doing.

... from OP

Medium: Organic soil containing upgraded black peat, granulated peat moss and perlite.

I replied in your germination thread... Watering and feeding to runoff, is something that has been held over from "coco". His medium is peat based, aamof it looks pretty darn similar to what my girls (soil) looks like. If you water to 10% runoff, my plants will remain sodden for 6-7 days. So based on the recommendation of the local hydro shop and a few other local growers, you don't water to run off (in a peat based mixes. Where are the plants getting their O2 from? I also get a giggle from those who choose vermiculite as a component in their medium, further exacerbating the "wetness" of the medium. The only time vermiculite should be used IMHO is in/during arid conditions.

 

[Subu]

Thanks all - especially therevverend. I definitely under-nuted my plants intentionally because I had heard these landraces would be quite sensitive to nutes (which the Malawi plants seem to be, but not the others).

I will try some cal/mag and start feeding 0.75x doses of my flowering nutes which contain potassium & phosphate. I assume they didn't contain Cal/Mag as they are organic.

Regarding watering & run-off: thanks for the advice. I'd been producing minimal run-off and it's working fine; I'd already been careful with watering to a degree as I had observed these LEDs don't evaporate water from the soil like HPS lights can.

 

[Subu]

But what about the Malawi

Nearly forgot guys - what do you think is wrong with the Malawi?

 

[RED 1]

But what about the Malawi

Nearly forgot guys - what do you think is wrong with the Malawi?

You bag walls look unused,because you either transplanted whilst in flower, to repair issues,or,sinply you underwater and that"s why the soil looks dry and leaves start to yellow from bottom to top
You cannot reverse/stop the yellowing,a couple of flushes,and,finish them as they are

 

[Subu]

You bag walls look unused,because you either transplanted whilst in flower, to repair issues,or,sinply you underwater and that"s why the soil looks dry and leaves start to yellow from bottom to top
You cannot reverse/stop the yellowing,a couple of flushes,and,finish them as they are

Look at my photos and description - the Malawi hasn't had any issues with yellow leaves, it's just growing slowly and has dry, papery leaves.

They were transplanted into their current (final) pots approx. a week before flipping so like 5 weeks ago. The plants just haven't needed enough water for me to totally soak all the sides, they already get runoff with the way I am watering them

 

[RED 1]

Look at my photos and description - the Malawi hasn't had any issues with yellow leaves, it's just growing slowly and has dry, papery leaves.

They were transplanted into their current (final) pots approx. a week before flipping so like 5 weeks ago. The plants just haven't needed enough water for me to totally soak all the sides, they already get runoff with the way I am watering them

In both cases,Malawi with paper leaves,flowering plants with yellow leaves,your watering is the issue

 

[JustGrowing420]

Also if the soil is really dry, you may get what seems like runoff but actually is just water that passed right through cracks or sides, because it didn't get absorbed.

In case you are throwing away you "runoff" immediately, let the pot sit in the "runoff" for 10-20 minutes and see if it absorbs it back. If that's the case, it is not real runoff.

Try to saturate the soil once and see if they look any better.

 

[Common Sense]

Thanks for posting this Subu, it immediately caught my attention because I had been doing things practically identically to you in a very similar setup (LED, soil, organic fertilizer, same bags, same size of bags ...) except I only have a 2 x 2 tent. I had the exact same issues at about the same time into flowering. Leafs turning yellow very rapidly within a few days and finally dying from the bottom up without a warning sign of the plant showing N deficiency. I've only done three grows, so I am following closely to learn.
Finding out the real cause of the problem can be complicated because there are so many factors playing together and you may get conflicting advice.
If you do a lot of reading on the internet or in books, the sometimes (again) conflicting information sums up to Calcium and/or Magnesium deficiency if you look at the leafs closely and consider the timing. Ca/Mg deficiency, besides lack of supply, can also be caused by too low a pH or overwatering, so you may check the calibration of your pH electrode and measure the pH in the runoff water. dubi has recommended the pH to be 6.5-6.8 for soil grows, a little higher than other sources. Getting an EC meter is also a good advice, they are not expensive.
At first, I had suspected overwatering to be my issue, so I ruled that out in the next grow and also paid more attention to the pH . Again, I ran into the same problems. In the end, after supplying Ca/Mg I could still get a decent harvest although, as has been stated, you can not reverse the yellow leafs. After reading through a lot of the threads here, I get the feeling there is an increase in posts where expert growers note that they have to supply additional Ca/Mg with LED grows.
Since your setup and problems are very similar, I would be interested in the organic fertilizer you are using, I think it would be ok to name the brand here. I have used BioBizz Grow and Bloom, which I value very highly actually.
What I have found out is that the water in our house is run through an ion exchanger that substitutes most of the Ca++ and Mg++ ions with Na+ (sodium) to prevent clogging of pipes, devices etc. with our hard water. This very likely might have contributed to my problem. So you may also want to check your water source.
I don't think you have been underwatering. Anyway, I developed a habit of daily lifting the bags/pots and sticking my finger into the soil down to the second knuckle to get a feeling of the moisture. Cool and damp is good, sogged for longer periods is not as it suffocates the roots.

 

[Subu]

No worries - because my plants were only veg'd for 25 days (from sprouting) I deliberately didn't aggressively water the pots initially (because the roots wouldn't have filled the pots). Now I'm still watering enough such that plants are lasting 2-3 days before requiring further water... so I really do think it's about the lack of nutrients in my case [given I heavily under-nuted the past 3-4 weeks].

I'm not 100% sure what's going on with my other Malawi but I've been very careful about not overwatering it and have space in the tent so will just see how it goes unless anyone has any concrete suggestions for it.

Otherwise, I purchased some Dolomite Lime (organic Cal Mag) earlier today. I'll just provide a small amount to all plants, with starting a more robust flower nute schedule and seeing how I go...

 

[Subu]

Also if the soil is really dry, you may get what seems like runoff but actually is just water that passed right through cracks or sides, because it didn't get absorbed.

In case you are throwing away you "runoff" immediately, let the pot sit in the "runoff" for 10-20 minutes and see if it absorbs it back. If that's the case, it is not real runoff.

Try to saturate the soil once and see if they look any better.

Thanks, will give them a nice watering soon with lots of flowering nutrients and a small dash of Cal Mag

 

[Koondense]

Cal, Mg, add more water and check the VPD, probably the air is too dry for the temperatures...
All the best