Coco plant has me stumped...

[marcnh]

I'm very interested in this thread. Chiming in!
I'm not an experienced grower, but what about laying off the water more to give the roots more air? I've also noticed my plants (roots) like warmth in the morning of their light cycle. Good luck!

 

[mullray]

http://www.integralhydro.com/cocoscience.html

Try this link. I'll see if I can find you more. It tells you how to test pH in coir and explains a lot of stuff about the nature of coco coir (including buffering with Cal Mag). It may help. CANNA coco is usually very good but it does say that sodium chloride can be an issue in coco. It'll cause lock out also if present in too high a levels.

 

[grimweeder]

my water is hard water an isnt the best quality, i live in the uk (south east), the water is ok to use from the tap an the ph out the tap is around 5.6, most growers round my area jus use it from the tap without any problems.(i rarely take ph an ec readings tho an dont really have any problems from not doing so) ive been i coco for 3 years an only had probs recently for some reason. i think i can put it down to the cold as im growing in a outhouse now at the mo an not in my house. i never used to have temp probs but now i do kinda.(shitty british weather for ya.)
i have found the best way to feed in coco is to not feed them every water an to give them food every other water.
using cold water may be wots causing it if its too cold like fresh out the tap an you water often then the cold may cause the lock out etc as it shocks the plants, the cold is partly wot my problem was.
also if u feed every water then your maybe gonna get a build up of salts. ur supposed to flush coco regularly to get rid of salt build up from the nutes, last i read anyway. on a weekly/ fortnightly basis for flushing.(i dont bother really tho.) i read that on some coco specific site, cant remember where exactly.but its always kinda plagued me that i should do it.

when i flushed my plants to fix em i gave em just plain water an left it for a couple days then i fed a light/normal feed, they then started to green up again an grow as normal.


you all know why canna says not to flush with plain water dont ya.... its cos they sell products your supposed to buy to flush plants with.(im sure there is another reason but i cant remember wot it is.)
never seen any probs when using plain water to flush with jusd dont use too much.

 

[Rosy Cheeks]

CANNA cal mag (buffer) their bagged coco prior to sale wordtree so stop with the cal mag. They're showing what looks like an N deficiency (N is highly mobile and its deficiency shows in new growth) so hit them with a foliar spray to compensate for now and they should come good. Perhaps raise the lights to gently help them along also.

Best advice I found in this thread,

Most horticultural coco coir today is buffered, and there's absolutely no need to add cal mag, unless there's not enough in your nutes, and none in your water.

If you still worry about Ca and Mg, mix some bat guano into the coco. It's full of Ca and Mg, and will slow release it over longer periods of time than Cal mag. Besides, plants love this stuff above anything else...

I really can't say what type of problem this is, I've never come across it. I'm tempted to say N def or lockout, that's what it looks like to me, but it could be something else. Have you been giving them the full feed (4ml A+ 4ml B/l) or do you cut doses?

 

[wordtree]

under what conditions does N lock out? I don't think it is from me underfeeding. The Canna grow guide suggests 500-800ppm in veg and these 3 plants were given 750ppm just like the others, who seem to be doing just fine.
I am under the impression that there is not a lot of calcium or magnesium in my tap water, as it registers at ~50ppm out of the tap. I have quoted Canna in this thread as saying their products were designed for tap water with a starting ppm value of 150-200 (0.2ec).

 

[UpInTheCut]

If you have been giving Cal/Mag to the girls from the beginning and they seem to be doing worse,as time goes on. Just try not giving any Cal/Mag for a week and see/ observe if anything gets better. Either way you will know your answer, and from looking at the 2nd picture, won't hurt anything.
-UpInTheCut
I use worm castings with CoCo no need for Cal/Mag

 

[Massproducer]

Let your Ph drift to just above 6, cal, mg and P all are a lot More available when you are hovering around 6.

 

[UpInTheCut]

Let your Ph drift to just above 6, cal, mg and P all are a lot More available when you are hovering around 6.

I think your on to something bro. It didn't occur to me raise the PH to reduce the uptake efficiency.

 

[hazy]

Best advice I found in this thread,
...
I'm tempted to say N def or lockout, that's what it looks like to me, but it could be something else. Have you been giving them the full feed (4ml A+ 4ml B/l) or do you cut doses?

You've got to be kidding!!

I agree with not adding Cal-Mag, but then I have hard water, so don't use it. He's got little to no Ca in his water. But a N def??!

N deficiencies occur on old growth first. This is sick plants 101 guys come on.

under what conditions does N lock out?

Nitrogen uptake by the plant is not controlled by pH.

Now a low pH can be a bother to soil guys, because the low pH can kill the microbes that release the N from organic sources so the plants can use it and in this way cause an N deficiency.

At a high pH N can volitize. Goes away.

And of course there are antagonisms between nutrients. N can be held back by too much Ca.

It really doesn't sound like you're overdosing them on Ca.

Iron deficiencies show up on top growth as yellowing between veins.
Sure seems like the pics show top growth yellowing between veins to me.
Zinc and Mn show on the new growth too, but look different. In fact you may have a bit of a Mn def showing up there too, by the way the center of the leaf is a bit green.

Two things can cause this, assuming your telling the truth about not sloshing lots of cal-mag on them. Either you are not giving them enough Iron or your pH is too high and causing this.

At 7.3 pH, 50% of Iron is gone. Mn also locks out at high pH. Also at high pH Iron will precipitate with Phosphorous causing things like red stems and slow growth. My hunch is pH. But you say you feed at 5.8.
I'm a coco grower and keep my pH 5.8-6.2+.
Did you hit them with just your plain water once?

btw, a foliar spray is good medicine for Iron deficient plants. Helps them get what they aren't getting through the roots until you get it fixed.

Still a little stumped at things like this, when things seem like they're right but you get something like this.

edit: Retro^^, must be a hydro guy to recommend a pH range of 5.5 to 5.8. I'd never go that low in coco. To much risk for cal and mag defs.

 

[wordtree]

so you don't think the micros are locked out for these plants, hazy?
the canna a+b and rhizo should be a complete feed for plants as far as I know. The A part has the calcium, and the B part has the mg according to the back label. It just doesn't make sense to me that the nutes are insufficient in that regard. The other plants in the tent aren't exhibiting these symptoms. I will photograph them for reference tomorrow.
For reference-

CANNA Coco
A & B
NPK 5 - 4 - 3 5.0% N (total)
0,1% N (NH4)
5.0% N (NO3)
4,0% (P2O5)
( 2,0% P )
3,0% K
( 3,0% K2O )

5.0% Ca
( 7,0% CaO )
2,0% Mg
( 3,0% MgO )
0,8% S
( 2,0%SO3)
0,007% B

0,001% Cu
0,02% Fe (DTPA)
0,0003% Fe (EDDTA)
0,01% Mn
0,002% Mo
0,007% Zn
0,5% Fulvic- & Humic acids


what should I try to foliar with? I have been giving light doses of rhizotonic. Do you think a calmag+ spray will do any good (and what ppm)?

ADDENDUM-
I was thinking...perhaps this particular strain does not like 'wet feet' and prefers more basic conditions. If I let the coco dry out for a couple of days the pH should drift upwards and perhaps the roots will grab the adsorbed cations more readily. Any thoughts on those thoughts?

 

[RetroGrow]

I'm a coco grower and keep my pH 5.8-6.2+.

edit: Retro^^, must be a hydro guy to recommend a pH range of 5.5 to 5.8. I'd never go that low in coco. To much risk for cal and mag defs.

Hmmmm....interesting. But coco is a hydro medium, and most people recommend 5.8 PH, although recently, Rez came out with a 5.5 recommendation, and I know a lot of guys are following that. I'm going to try a higher PH on your advice with a couple of plants, maybe 6.0, and I'll see what happens.
Can't hurt to let the PH drift a bit anyway.
That way the plant is exposed to different PH ranges allowing different minerals to be in their optimum range for uptake.

 

[Hazy Lady]

Alg-A-Mic is an excellent foliar feed/tonic, organic, made from algae and seaweed it has an NPK of 0.1,0.1,0.1 with additional Mag 0.1 and Ca 0.2, it will replace any deficits while you find the actual cause of the problem not the symptoms. If you are going to grow in coco I suggest you sign up on Canna's site, the library available to members is second to none. It is fact site not sales driven as you might expect btw obviously as it's Canna not just for coco growers.
You don't mention your water-feed regime? or I missed it, there are a few basic rules with coco and when applied make coco growing a breeze but not following them shows symptoms like no other medium which makes diagnoses difficult and costly, far better to follow the basics and avoid all ill's. The most important ime is flushing in between feeds, for every 2 or 3 feeds you must flush, (with PH'd Water only) and to 10% run off*, this ensures your medium is balanced, no salt build-up and PH swings.
You want to be going in with your nutrient at 6.0 to 6.2 and you'll see a similar PH in the run off. If you don't flush you'll see your run off PH dropping into the 5's pretty quick, but you'll see sick leaves even faster.

* Coco 101 Rule # 2 Run off to at least 10%.

 

[3dDream]

If you add micros to your nutes some will die under a ph of 6.

 

[Fat J]

PH5.8 is great for coco IMHO - my results are good. If you know what you are doing and the flush didnt work, you could be looking at something entirely different. Many ppl lately have seen Root Aphid (Phylloxera) infestations come in with CoCo that was stored outside for extended periods. If you live in a grape-growing region and have a 30x+ loupe or mag glass, dig a lil of the top medium away and look closely with the loupe. If you see little clear bugs crawling on the roots, then I strongly suggest you read the "Root aphids aka phylloxera" thread. My RA problem looked a lot lie that - also u see any little gnatlike things flying around occasionally?

Hopefully u dont have em but it cant hurt to check.

 

[knna]

It seems a problem related to micros. Its the usual when top leaves yellows while the rest seems healthy.

I cant say exactly what micro is the problem, although the main candidates for that intervenal top chlorosis are Zinc and Iron (Fe). You can fix a deff of both using a foliar application of a algae extract, as Hazy Lady pointed out, algae extracts are rich on Fe and Zn.

The most usual cause for any of both deff is ph too high. Cold temps may cause it too or aggravate the problem caused by ph (cold and high ph difficults those micros uptake).