Diagnosis required

Hi, the attached pics are of a plant about 10 days under 12/12. 3/4 are looking fine but this one seems to be lacking something. It's new growth is yellower than the other plants and the lower fan leaves are deteriorating quicker. The other fan leaves are now notably curled.
From what I read this could be N deficiency, although I have given it some, but I also see it could be a zinc deficiency. However, perhaps as it's flowerings, it's crying out for P & K. Can anyone help pin this down? Thanks in advance.

I hope I haven't broken a code of conduct as no-one seems to be replying. I attach a couple more pics if there is anyone out there who could assist. Thanks.

are you supplementing magnesium?hows the soil PH?whats the grow area tempeture?if you can answer these questions we can narrow it down,find out and let us know,Im sure that someone will have a remedy for you....bonbon
http://oregonstate.edu/dept/hort/dpd/chemkey.htm

Sorry, dumb of me not to put that (it was on another post).

ph c. 6 - 6.5
Humidity 20- 30% (too low)
Temp 25 - 30 oC (too high)
Ferts so far : small amount of ammonium sulphate (N) in veg and small amount of Fishblood/bone (5-5-6.5) during flowering (c.10 days in under 12/12).
Couple of more pics attached. Thanks for the link also.
I still can't decide if it's N an deficiency, or lack of P during flowering. Magnesium and subsequent nutrient lock does sound plausible as I haven't given't it any Mg. In one of the pics, you can see the other plants looking fine (although their lowest fan leaves are starting to droop and yellow).
Anything else I can help with let me know (there may be some more info in my other post on indoor growing msg board "Advice welcomed")

Thanks for taking the interest and your time.

Cheers.

I think I will go with the following excerpt:

1. OLDER LEAVES CHLORTIC, usually necrotic in late stages. CHLOROSIS ALONG LEAF MARGINS EXTENDING BETWEEN VEINS PRODUCES A "Christmas tree" PATTERN. Veins normal green. Leaf margins may curl downward or upward with puckering effect. Necrosis may suddenly occur between veins. POTASSIUM or CALCIUM EXCESS can inhibit uptake of magnesium... MAGNESIUM DEFICIENCY
When the external magnesium supply is deficient, interveinal chlorosis of the older leaves is the first symptom because as the magnesium of the chlorophyll is remobilized, the mesophyll cells next to the vascular bundles retain chlorophyll for longer periods than do the parenchyma cells between them. Leaves lose green color at tips and between veins followed by chlorosis or development of brilliant colors, starting with lower leaves and proceeding upwards. The chlorosis/brilliant colors (unmasking of other leaf pigments due to the lack of chlorophyll) may start at the leaf margins or tips and progress inward interveinally producing a "Christmas" tree pattern. Leaves are abnormally thin, plants are brittle and branches have a tendency to curve upward. Twigs are weak, subject to fungus infection usually leaves drop prematurely; plant may die the following spring.

I guess I give it a good flush and start of again with a weak flowering fert.

Thanks bonbon

water with epsom salt(1tbs disolved in 1 gal water),i dont think you have to flush since you were giving it a modest amount of fertilizer,the ph is ok at 6-6.5,the mg will bring it up slightly,add a little more phosphorous on the next feeding,the humidity is low because of the hot air,i would just use an outake fan for now and one on the plant,the outake should be able to draw in enough cooler fresh air air,Im sure you're diagnosis is correct also,it will take several days to see an improvement,if the low humidity is still a problem,a shallow container with water in the area should help,good luck to you an post the results....bonbon

Thanks for the advice bonbon. I'll give that a go today and post an update soon.
As you may have worked out by now, I have recently bought a new digital camera, hence all the pics attached! I'm gonna attach the last two now, as I hope they may serve other growers in future. They're of another plant which hasn't got the curled leave problem but the middle fan leaves are starting to discolour. I'll give these the same treatment as the sick one as I'm sure they'll all be lacking the same thing!

I think (and pray) this is doing the trick! I attach a couple more pics - 1 of the baby that was really suffering (seems to be in a better state of health today) and another of one which was showing symptoms on the middle fan leaves (this is getting worse but I hope I've stopped the rot, so to speak).
A question has now occurred to me. Should I remove the damaged fan leaves? I'm guessing I should (cleanly of course) but does it do any harm leaving them there to fall off naturally?
Thanks for a reply.

Sorry, pics attached

I took a close look at the pic and i thought i saw beads of water caught on some webbing,then a look at the leaves for the little spots,Im sure those are spider mites http://www.cannabisculture.com/backi...ite/index.html

I attach a couple of pics for a weekly update. I fed them some epsom salts and have just given them some phospurus. It certainly seems to have stopped any rapid degradation so I'm hoping it's working. However, I don't think something's right with one of the plants, and I'd be really grateful for some further advice.
As far as I'm aware, both plants have been given the same amount of nutrients (I can't recall if they're all in multi purpose compost, miracle gro compost or a mix of both - I'll try remembering next time!), but one is seemingly very healthy and the other is definitely showing signs of some 'sickness'. I'm hoping that the leaf discolouration will be an obvious clue for an expert to diagnose exactly what the problem is. I'm not even sure if I'm over or under fertilising! I guess the latter as the more vigorous grower seems to be suffering, but I'd hate to guess wrong!!
Thanks in advance for any help that's offered.

Quote:

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Originally Posted by mrrichiet

I attach a couple of pics for a weekly update. I fed them some epsom salts and have just given them some phospurus. It certainly seems to have stopped any rapid degradation so I'm hoping it's working. However, I don't think something's right with one of the plants, and I'd be really grateful for some further advice.
As far as I'm aware, both plants have been given the same amount of nutrients (I can't recall if they're all in multi purpose compost, miracle gro compost or a mix of both - I'll try remembering next time!), but one is seemingly very healthy and the other is definitely showing signs of some 'sickness'. I'm hoping that the leaf discolouration will be an obvious clue for an expert to diagnose exactly what the problem is. I'm not even sure if I'm over or under fertilising! I guess the latter as the more vigorous grower seems to be suffering, but I'd hate to guess wrong!!
Thanks in advance for any help that's offered.

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P.S. I certainly could find no evidence of spider mite (I'm also in the UK and I've never heard of the problem over here)

Definatly no signs of infestation. Those are water drops. The plants would have tons of spots on them if they were infested with mites.

Keep us informed on the outcome.

Quote:

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Originally Posted by Oregon Green Free

Definitely no signs of infestation. Those are water drops.

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I concede my misreading of the photo(clicked on the pic for full size)I was looking at wet reflective material(sure looked like webs at a glance)sorry,....But i still think your problem a nute deficiency(major,macro,secondary ) combined with heat build up,but maybe an expert will contradict that?good luck....bonbon

Thanks once again bonbon. I've bought another fan now so have an intake and exhaust which keeps the temp at about 25oC on a hot day, so that's a good improvement. Humidity is still around 30% though, so I think I'll have to buy a humidifier for the final stages of flowering. So far though, I think you advice has been excellent :)
I don't suppose you're able to post a link to a decent page regarding the major, macro and secondary nute problems, as I haven't read about those classifications before? Thanks in advance if you can.

http://www.onlinepot.org/grow/nutrients2.htm
http://www.onlinepot.org/grow/nutrients.htm
http://greenmanspage.com/guides/nutrientdisorders.html
http://www.cannabase.com/cl/bcga/bcga/nutrients.htm

Thanks dude :cool:

Quote:

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Originally Posted by bonbon

http://www.onlinepot.org/grow/nutrients2.htm
http://www.onlinepot.org/grow/nutrients.htm
http://greenmanspage.com/guides/nutrientdisorders.html
http://www.cannabase.com/cl/bcga/bcga/nutrients.htm

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thanks man
i was looking for certian info i found,,,,nice one

Quote:

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Originally Posted by NowhereMan

thanks man
i was looking for certian info i found,,,,nice one

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you're welcome my friends....bonbon

your plants look like they might be suffering from irregular watering or perhaps sudden changes in feeding... air temp and humidity are important, but one of the chief problems indoors is air exchange and ventilation... your plants are nice, and strong,..... give them a couple of long drinks of plain H2O, and then try a mild solution of seaweed extract, and fish emulsion.. this will bring them to a pretty nuetral state and them you can begin to experiment with other things...YOU ARE DOING GOOD! horticulture takes time and patience.. hasta :)

man i love this place.....

Thanks hasta for the last tip, it's one I'll bear in mind in future.
I started using the UK420 forum (no offence guys) so haven't been back here recently, so I thought it'd be courteous to let you know how it went on. I'll attach a couple of pics and you can see for yourselfs, but basically, whilst all the fans leaves browned and died, I still got some very pleasant bud!
My next lot have started flowering (although 3 had to go outside as they started hermying - I think this was due to going into strongly fertilised soil too soon as they started growing double branches straight after they were potted in it) and they're starting to show the same symptoms. I've given them ferts and Mg so I don't think this is the problem. I think therefore that hasta was on the right track.
As he says though, it comes down to practice and patience so I'll keep plugging away until one day I get it susses!

Following the above post, here's some pics of a new plant. Note the limp lower leaves (show no sign of discolouration/necrosis) and the necrosis starting around the viens on the upper leaves. Any suggestions anyone? My next try was going to be up the ferts/Mg or try Fe. There's not a lot I can do about the airflow, but I'll make sure she's watered properly from now on (per OT1's schedule on UK420 ;-))
(Pics to follow in next reply- having trouble right now!)

(I hope)

A couple more

Heat stress in my latest opinion of this problem.

i think what you see now is because of how much water you are spraying on your leaves. the burns appear to be on points of the leaves where the water collects (in the veins and the tips). this could be for one of two reasons either the water drops are acting as magnifying lenses and the lamp is burning them or the plain water has some sort of residual that the leaves find irritating or perhaps the pH of the residual is having a local effect on the leaf tissue. hope this helps you. it looks like you are doing pretty well for not being an expert. good luck you'll be one soon!