Fan leaves gone crispy, burn or deficiency???

[poindexterous]

So I'm a bit baffled with this symptom. Fan leaves started going crispy from the tip inward about 2 weeks into bloom, finally consuming the whole leaf, later smaller leaves got it. Nutrient was never over 1000ppm, reduced to 500ppm as soon as it started, and it still got worse. Never looked like typical nutrient burn as I'd seen before, unaffected leaves didn't have even slightly burnt tips, lower and mid leaves effected first. I'm top feeding pro-mix/perlite 2to1 mix, use GH nutes, always water till runoff to flush mix. Plants showed no other distress, leaves perky and upright till they fried, temps a bit high in the 80's but no worse than many past rounds. What have I done wrong here????

 

[MIway]

Looks like Phosphorus... from a bit ago, not recent. New growth & shoots look nice!

Have you added anything to occasionally adjust up your pH? I use the 3 part in Promix as well & like to add back DL every other week, just as a pH maintenance item.

What's your feed schedule?

 

[michigan.mmma]

2 weeks into bloom...... do you have root aphids?

thats how they get ya. everything looks great then about 2 weeks into bloom you see lockouts/deficiencies but you have changed nothing. leaves get chlorotic then necrotic and are paper thin at the edges.

do you have fungal gnats? are there any very tiny crawlers in your meduim?(may have to look with a magnifier/loupe)

 

[poindexterous]

Looks like Phosphorus... from a bit ago, not recent. New growth & shoots look nice!

Have you added anything to occasionally adjust up your pH? I use the 3 part in Promix as well & like to add back DL every other week, just as a pH maintenance item.

What's your feed schedule?

Hey MIway, yeah it's weird how some growth looks fine while the fans totally fried, it's progressed to most all leaves since that picture, definitely gonna have reduced yield with few leaves left. I've kept pH steady between 6.0 to 6.3 using GH raise. I top feed once daily till runoff. I assumed overwater should cause droop and yellowing which mine don't have at all, they're perky and dark green till they go totally crispy, alas!

 

[MIway]

Promix, once per day, Phosphorus def... wet/soggy roots bro... that's likely your uptake issue. Although I noticed you cut 2:1 with perlite, so, imo, are kinda getting away with it... as in, you don't have significant drooping & undercurl. dunno, this is a guess here, but would make sense.

You shouldn't fear letting the top of the Promix to go flaky dry... for the top inch or so... before you water again... and to full run-off like you said.

Might want to look into throwing a pure pH'd water cycle in there too... like a feed/feed/water/repeat... or a feed/water/water/repeat... and that cycle should get you through a solid week+. Let em dry out a bit. But they look good, all things considering... really good!

 

[poindexterous]

2 weeks into bloom...... do you have root aphids?

thats how they get ya. everything looks great then about 2 weeks into bloom you see lockouts/deficiencies but you have changed nothing. leaves get chlorotic then necrotic and are paper thin at the edges.

do you have fungal gnats? are there any very tiny crawlers in your meduim?(may have to look with a magnifier/loupe)

Root aphids no, fungus gnats yes, but there's always been a few gnats around for as long as I've grown, and they're actually very few in number right now, hardly any on the sticky trap. I've had perfect rounds with 100X as many gnats as I do now, so I doubt it to be them.

 

[RubeGoldberg]

I've kept pH steady between 6.0 to 6.3 using GH raise.

What does the runoff measure out at?

 

[poindexterous]

Promix, once per day, Phosphorus def... wet/soggy roots bro... that's likely your uptake issue. Although I noticed you cut 2:1 with perlite, so, imo, are kinda getting away with it... as in, you don't have significant drooping & undercurl. dunno, this is a guess here, but would make sense.

You shouldn't fear letting the top of the Promix to go flaky dry... for the top inch or so... before you water again... and to full run-off like you said.

Might want to look into throwing a pure pH'd water cycle in there too... like a feed/feed/water/repeat... or a feed/water/water/repeat... and that cycle should get you through a solid week+. Let em dry out a bit. But they look good, all things considering... really good!

Thanks for the perspective. I had thought about overwater but though without droop it couldn't be, but maybe that's it? To late to really fix it now with few leaves left, but I'll at least stop watering till the pots get light. Next round gonna restrain my self and let em dry out more.

 

[poindexterous]

What does the runoff measure out at?

Hey Rube, runoff comes out about same as it goes in so far, but I'll check it again next cycle.

 

[Tr33]

you have root aphids
not nutes no way

thats classic root aphid damage

you may think you have gnats, but those are RA for sure.

 

[michigan.mmma]

Root aphids no, fungus gnats yes, but there's always been a few gnats around for as long as I've grown, and they're actually very few in number right now, hardly any on the sticky trap. I've had perfect rounds with 100X as many gnats as I do now, so I doubt it to be them.

sorry i didnt mean if you have gnats that they are your problem. the gnats are a sign of RA presence. you have the classic symptoms of RA infestation. i went around in circles the same way looking at deficiencies, ph problems, overwatering, etc etc etc.... if your leaves are crisping up like that from top to bottom i would bet $ you have RA's. look at your media with some magnification device you will probably see those tiny critters...

check the RA threads, you can see the pics. the plants look the same. i have had them. they are devastating.

"Fan leaves started going crispy from the tip inward about 2 weeks into bloom, finally consuming the whole leaf, later smaller leaves got it. Nutrient was never over 1000ppm, reduced to 500ppm as soon as it started, and it still got worse. Never looked like typical nutrient burn as I'd seen before, unaffected leaves didn't have even slightly burnt tips, lower and mid leaves effected first"

to me this says it all right there. phantom deficiency, 2 weeks into bloom, crisping leaves outer to inner on whole plant, not like typical nute burn. you can give these plants perfect ph/nute water and they will crisp up. unfortunately i have lived that myself. you see the nute adjustment did not affect the plant. the RAs are causing any type of lockout/deficiency at the root zone.

 

[MIway]

Thanks for the perspective. I had thought about overwater but though without droop it couldn't be, but maybe that's it? To late to really fix it now with few leaves left, but I'll at least stop watering till the pots get light. Next round gonna restrain my self and let em dry out more.

I don't think I'm steering you wrong here... genuinely think it's a bit soggy in there, which I've noticed P being sensitive to, along with pH.

Been in a whole warehouse with RA's... really badly infested... they didn't know they even had them & it was throughout the place... everywhere, even in the cutting rooms. The black ones with the red mark on their backs are just scary looking.

Anyway, whole place was in the shits, nothing looked like yours bro... they look/get real sick, pretty darn fast. Hoping that's not the case with you man.

Loosen up a pot & pull the root mass... stare at it for 10-15 minutes. If you have RA's... you will see them. In which case, Bayer Complete is the answer, but do it quick. Peace bro.

 

[poindexterous]

Hmmmm.....well I'm gonna do a thorough root aphid inspection to be sure. If it were aphids should I expect to find the winged adults on my sticky traps or do I really have to bust open a root mass to find them? Also all my plants in veg are consistently fine, just gets crispy into bloom, not sure what that means?

 

[poindexterous]

So I looked over the several hundred or so winged critters caught on my two sticky traps and every last one looks to be a fungus gnat, slender and mosquito like, nothing else. Could I really have soil only aphids without flyers? And would they be in the top inch of soil so I would find them without tearing into a root mass?

 

[michigan.mmma]

Hmmmm.....well I'm gonna do a thorough root aphid inspection to be sure. If it were aphids should I expect to find the winged adults on my sticky traps or do I really have to bust open a root mass to find them? Also all my plants in veg are consistently fine, just gets crispy into bloom, not sure what that means?

you may not find any winged RAs at all. you may only find them in the root zone. Plants in veg could be affected but usually dont show signs until 2-3 weeks into bloom. that is classic RA signs. Everything ok in veg and even 2-3 weeks of flower then everything gets crispy.

" So I looked over the several hundred or so winged critters caught on my two sticky traps and every last one looks to be a fungus gnat, slender and mosquito like, nothing else. Could I really have soil only aphids without flyers? And would they be in the top inch of soil so I would find them without tearing into a root mass?"

yes you can have RAs in the root zone but no fliers. not sure how far into the root zone you will have to look. do you have a loupe or magnifier? you can loosen a bit of the top layer and start watching closely for the little bastards

 

[poindexterous]

Argh, well this burned batch ended up ripening early at 5.5 weeks form all the leaf damage/loss, yield pretty weak but glad it's done so I can start a new one at least.

So after breaking up a root mass and thorough inspection with a good microscope I can say for sure not a bug of any kind in there, not even a fungus gnat larvae to be found, so it was either an environment or nutrient issue.

Roots looked fine and were throughout the pro-mix but not enough of them to really bind it together like with a healthy grow when it's a solid cylinder of roots at the end, broke apart too easily. Pro-mix/perlite mix is still nice and loose and evenly moist, not too wet seeming, but maybe it was earlier? It's either that or this strain can't handle summer temp's in the 80's? Just can't think of any other reason? I even tested the soil for salts by adding RO water then squeezing out and checking TDS, squeeze-water only read 300ppm.

 

[RubeGoldberg]

double check the ph meter against some litmus paper testing tapwater, not RO (just because tapwater will read more stable and consistant)

sometimes meters will go off even if they're calibrated.

Theres some x-factor at play here

imo i don't think it was the temperatures, the damage is too severe for anything like that.
Also it doesn't sound like you were overfeeding and burning them necessarily.

What schedule were you using for the GH nutes as far as ratios and ml/liter or gallon amounts? Also additives, clearing agents etc Basically anything that was entering the root mass

 

[poindexterous]

Yeah, doesn't seem like high temps as the tops closest to the lights don't show typical heat effects at all, if anything the burn starts low and moves up. I have two pH meters that I calibrate often and they stay within 0.1 of each other.

I've been using GH at the 1-2-3 bloom/3-2-1veg(grow-base-bloom) ratio for over a decade with great results in the past, even used to get a gram per watt for a while, but now I can't seem to shake these leaf symptoms? I also add a little cal-mag to compensate for the RO water. I used to grow in 100% perlite and recently switched to the pro-mix/perlite mix in hopes of it being a solution. Even started wondering about it being a virus for lack of a better answer. Maybe the daily irrigation was too often and the media needed to dry out more, just seems odd as with near 40% perlite it drains so well, plus in veg they are entirely happy with the same watering rate, still for lack of a better idea I'm gonna let them dry more. Maybe 1000ppm was not enough and 500ppm just made it worse? Hard to believe they'd starve at 1000ppm? All very baffling, alas!

 

[RubeGoldberg]

Agreed a bit on the daily irrigation, since the roots will spread out better in pro-mix if they're allowed to dry out reasonably between water entering the roots.

constant feeding could lead to root rot, especially once the plants get a bit weaker after around the 2-3rd week of flower.

really looks like a burn though considering it started at the tips.

do you have ml per liter rates for your 1-2-3 / 3-2-1 ?

 

[poindexterous]

If I add 100/200/300ml grow/base/bloom to my rez which is around 50 gal it ends up about 700ppm, so I'm in that range, give or take, to make 500 to 1000ppm.

When I used to top feed perlite I'd be up to 2000ppm and never had burn, but assume in pro-mix you have to be lower, since it absorbs more nutrients? I wonder if I could possibly have deficiencies instead of burn? Sure don't want to go in the wrong direction.