Strawberry Pie Autos Suddenly Developing Curled Leaf Tips and Brown Spots on New Growth

Delps8

Well-Known Member
I'm having some nute issues and I'd appreciate some feedback on what's causing it and potential remedies.

The symptoms are that a few of the leaves at the top of the canopy on two stems from one plant ("Alice") and one leaf at the top of the canopy on the other plant ("Annie") have suddenly developed a few light spots on the leaves, numerous dark tan/light grown spots in a handful of leaves, and those leaves and a few others have leaf tips that are slightly curled.

Alice was slow out of the gate during germination, is noticeably smaller than Annie, and, during veg, was not able to handle as much light as Annie.

The plants were vegged using a Growcraft X2 veg light and the amount of foliage is significant. All foliage is strong and solid green. The only other issue that I've seen in the foliage has been from nutrient water falling on the leaves in early veg. Interestingly, those leaves are still visible and the damaged areas have neither overgrown or deteriorated.

I've removed dead and dying fan leaves and poorly developed branches from the under carriage.

First symptoms were two days ago, when I first saw that some of the leaf tips were slightly curled but the discoloration has manifested in the last 36 hours.

I've checked the symptoms against the standard symptoms charts and the only thing that looks like it might be the culprit is magnesium but that's a mobile chemical that would impact lower leaves. Given that this is occurring on new growth could it be calcium or magnesium?

The details on the grow are here. I haven't posted much about this grow in the grow journal so the details on this issue are here:

Two Strawberry Pie autos in flower, 56 days since germination.

Light-PPFD and DLI data at the end of the posting. I've dropped DLI a bit over the past few days. Some spots have had PPFD's in the low to mid 900's but the average value for the top of the canopy has had a DLI's in the high 50's and low 60's. Photoperiod is 20/4. Lights are out from 1630 to 2030 - that cuts my cost per KwH from 61¢ to 34¢ and drops my lighting cost from $110± to $65±. Gotta love California.

Temperature-very stable with lows in the mid 70's during lights out and highs in the low 80's.

Humidity-not as stable as I'd like because the grow is in an unheated garage in SoCal. The past few days have been lows at 60°± and highs in the mid-70's.

Wind-AC Infinity fan blowing at 1/10 over the canopy.

CO2-ambient.

Root zone temperature-water chiller keeps the res at 68°

Water - RO water at 0 PPM. Water uptake has been 1 to 1.5 gallons per day.

Nutrients - Jack's 3-2-1 mixed at the current recommended mixture of 3.79-2.52-0.99 gm/gallon.
Reservoir is new as of 10/22/22 at 860/550 PPM//EC 1.72. Due to water uptake and topping up, PPM is 820/500//EC 1.64. Over the course of the past two days, PPM has fluctuated between 810/500 and 820/500.
pH has been as expected. Over the past three grows, when I swap the res, pH drops very slowly for two or three days and is then stable. In this res, pH dropped for two days.
Unlike previous grows (2 Gorilla Glue grows and 1 Gelato, all autos), I have seen this res exhibit the "EC dropping, pH rising" behavior that hydro grows typically exhibit. The previous res started at 790/500 but PPM dropped over the course of the week and it was 590 PPM when I swapped the res.

Oxygen-no changes since I started growing. Using BubbleMac airstones are were sterilized at the start of the grow and were functioning as expected when checked during the last res swap.

Roots-pure white with fresh dirt smell when checked during the last res swap.

Light Data
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I just had a very similar problem with an auto. At about 40 days from germination, mid-stretch I got these brown spots on top leaves. It quickly got from bad to worse. It was most prominent on top leaves that were getting most light. I was at about 900 ppfd (metered with a phone meter).

My diagnosis was that it was a calcium deficiency, excarbated by the strong light. I got the plants to harvest but they took a massive hit from those issues.

Also,looking at your pictures that might also be more of a light burn. My spots were more "spotty", like round :)

I'm in 100% coco Hempy's,so it's not the same exactly. I use Terra Aquatica 2 part Coco, which has calmag in it, but not enough apparently.

I would (and plan to in the coming grows) rinse asap, add calmag and slightly raise the lights.

I'm no expert and hopefully someone more skilled will soon chime in, but this just sounded so similar to what I just experienced, I thought I'd give my 2c.

Hope it gets better!
 
ALSO IS UR PH LEVEL OK COULD BE THAT THE INTAKE OF THE NUTES MIGHTEN BE GETTIN IT CORRECTLY
pH has ranged between 5.7 and 6.0 and light levels are down a bit.

I believe that @CB2O has ID'd the problem as being a Ca deficiency. I'm using Jacks' 3-2-1 mixed IAW their instructions but the fact is that I've got to deal with what looks to be not enough Ca.
 
I just had a very similar problem with an auto. At about 40 days from germination, mid-stretch I got these brown spots on top leaves. It quickly got from bad to worse. It was most prominent on top leaves that were getting most light. I was at about 900 ppfd (metered with a phone meter).

My diagnosis was that it was a calcium deficiency, excarbated by the strong light. I got the plants to harvest but they took a massive hit from those issues.

Also,looking at your pictures that might also be more of a light burn. My spots were more "spotty", like round :)

I'm in 100% coco Hempy's,so it's not the same exactly. I use Terra Aquatica 2 part Coco, which has calmag in it, but not enough apparently.

I would (and plan to in the coming grows) rinse asap, add calmag and slightly raise the lights.

Many thanks for the info but sorry that your grow took a hit.

Re. light - I haven't seen any light issues for some weeks and, per the chart below, DLI is down a bit in the past few days.

Alice has been impacted the most, Annie's had only a few impacted. There's no a lot of change today, fortunately.

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Here's how I track my light:

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285-watts
103/105-is hang height in inches and tents of an inch
20-photoperiod
The measurements in the table are µmols taken at the various spots in the canopy.
"62/57" - the DLI for the max and average values in the table. For Alice, I knock out the front reading (why don't I do that for Annie?) and for Annie I knock out the right edge reading. I get a better sense of the high values that way. Nothing but personal preference (personality quirk).
Now that I have to explain it, I realize that I'd skewed things by not knocking the front of the tent reading for Annie. I missed that in the code review… :-)

62/57- max and average values for the samples, with the exceptions noted above.
155- the standard deviation of the readings and, per those values, the canopy is not very flat. :-(


I think you hit it on the head with Ca being the issue. Leaves have been dropping as expected and I noticed that the stems of some of the fan leaves were hollow. That could be perfectly normal but one source I read said that hollow stems are a symptom of a Ca deficiency. Also, Alice is noticeably smaller than Annie and a Ca deficiency could contribute to that.

And then there's the honkin' big splotches on the leaves so I think you're on target calling is a Ca issue.

This page confirmed your analysis and they recommend increasing Ca by 0.2 EC (100/500 PPM). That's a lot of Ca, seeing that Jack's provides only 140 (elemental) PPM so my "history major brain" says that increasing Ca by 70% might be a bridge too far. My thinking is to bump by 25% or 35 PPM and, wouldntcha know that Botanicaire's CalMag contains 9 PPM per ML so 35/9≈4 (that's "history major math"). The res is down to about 23 gallons so it's just a small beaker away from the road to recovery.

This res is about a week old which is enough time for Ca to have been somewhat depleted* so I'll drop in the CalMag now and do a fresh res tomorrow with a tad more Part A.

*For info on nutrient reservoir depletion look for the Bugbee paper entitled "Nutrient Management in Recirculating Hydroponic Culture" and grab a copy from research gate.net. It's a really good read and helped me understand the rationale behind topping up with water instead of water+nutes.


I'm no expert and hopefully someone more skilled will soon chime in, but this just sounded so similar to what I just experienced, I thought I'd give my 2c.

Hope it gets better!
I really appreciate your timely, appropriate response. Your observations are pertinent and your arguments are sound. I'm not sold on the "too much light" idea but I think you're spot on re. Ca being the problem.

Ca isn't take up immediately but I'll drop the CaMg in the res now and leave the pH at 6.0 (it hit 5.9 early yesterday and then 6.0 this AM) and the new res tomorrow should seal the deal.
 
pH has ranged between 5.7 and 6.0 and light levels are down a bit.

I believe that @CB2O has ID'd the problem as being a Ca deficiency. I'm using Jacks' 3-2-1 mixed IAW their instructions but the fact is that I've got to deal with what looks to be not enough Ca.
Hope u find the problem mate sum serious lads in here growin i no ul get ur answer off sum1 . I habemt been at it ina while but did have a similiar problem before sorry i couldnt help more happy growin mate 🤙🤙
 
Hope u find the problem mate sum serious lads in here growin i no ul get ur answer off sum1 . I habemt been at it ina while but did have a similiar problem before sorry i couldnt help more happy growin mate 🤙🤙
Thank you. I appreciate that. Happy growing to you, as well. :bongrip:
 
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