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Yellowing Leaves Habanero/Bhut Under LED

Posted by ctempz NZ (My Page) on
Thu, Nov 7, 13 at 4:09


New to the forum here. I have had a look around to try and find the answer to the question I have.

I am growing a variety of chillies from seed, under two 300w rated LED light panels. Each light has a more realistic power output of about 180-200 watts. The cabinet walls are lined with mylar and there is an active air intake/output. Lights are on 18, off 6. The floor area is 1200mmx900mm and the lights are roughly 70cm above the plants.

All the plants are very stocky. I may need to stretch them by raising the light soon i think.

My Habaneros are VERY short and the leaves are yellowing heavily, at times almost going white.

They are about 6 weeks old.

I have been feeding them with Chilli Focus and given them some fish emulsion.

I am waiting on a ph meter so i can get a better idea of the soil ph.The soil is a mixture of organic potting mix for vege etc and perlite.

Is the problem a lack of calcium? will bonemeal help fix this? or should i just leave them and hope they come right.

Some of my bhut jolokias that were looking healthy are starting to show the same symptoms.

any help would be appreciated, i am very new to this.



Follow-Up Postings:

RE: Yellowing Leaves Habanero/Bhut Under LED

Habanero pic

RE: Yellowing Leaves Habanero/Bhut Under LED

Yellowing bhut

RE: Yellowing Leaves Habanero/Bhut Under LED

Healthy Bhut

RE: Yellowing Leaves Habanero/Bhut Under LED

Healthy bhut

RE: Yellowing Leaves Habanero/Bhut Under LED

Grow setup pic from a few weeks ago. Habs are bottom right, bhut jolokias are top left. Top right are thai super chilli.

RE: Yellowing Leaves Habanero/Bhut Under LED

Temperatures in the grow cabinet range between 15 deg centigrade when the lights are off and up to 32 deg when on - if its hot outside. seems to generally sit about 28. Humidity is ranging between 50% and 80%.

RE: Yellowing Leaves Habanero/Bhut Under LED

Noticed some key points that you mentioned in your first post... two 300w LED fixtures suspended about 28", photo-periods of 18 hours, leaves yellowing/almost turning white, plants approx. 6 weeks old, and using fertilizer.

A couple possibilities come to mind. Your light may be too intense. Raising the fixtures and tweaking your photo-periods might be worth a try. You may also want to re-consider your fertilizing regime; eliminate using them for awhile to see if there is any improvement (and then resume fertilizing lightly when your plants start maturing). Don't know if these suggestions will help rectify your situation, but they may be worth pursuing.

This post was edited by o2tiller on Sat, Nov 9, 13 at 19:13

RE: Yellowing Leaves Habanero/Bhut Under LED

Hi ctempz and welcome to GardenWeb,

Regarding the problem of your yellowing chillies, my guess would be a lack of nutrients. Abnormal yellowing of leaf tissue is called chlorosis (lack of chlorophyll). Some things that can cause the problem would be over-watering, poor drainage, damaged or compacted roots, high soil pH, and especially nutrient deficiencies.

Of all the things that can cause plant chlorosis, one very common one is the lack of iron. When you see chlorosis showing up first in the newer growth, especially if the veins seem to remain green, suspect an iron deficiency. Nitrogen deficiency, for example, usually shows first in the older leaves as a uniform yellowing of the entire leaf (including the veins). Your plants could be suffering from a lack of both iron and nitrogen, as well as a few other nutrients.

No guarantees, of course, but if they were mine, I'd give the plants a feeding of a good water soluble fertilizer high in nitrogen and containing a good percentage of iron. Miracle-Gro Miracid for example contains 30% nitrogen and .325% iron. That fertilizer is normally used for 'acid loving' plants but I think your chillies would be fine if the pH didn't drop below about 6.0.


RE: Yellowing Leaves Habanero/Bhut Under LED

Thanks for the really informative posts.

I have raised the lights higher to eliminate light being too intense as a problem. I also want them to stretch a little so this is a good change anyway.

My ph meter finally arrived. The first thing i did after calibrating was to test the ph of the tap water that i have been watering with.

the reading was 7.6.

After reading art33's post, it makes me think that this may be the major cause of my problems, the high ph locking out nutrients from reaching the plant.

I cannot seem to source Miracle-Gro Miracid here in New Zealand.

At this stage I was thinking an alternative may be "sulphate of ammonia". from what i have read this will lower the ph and add nitrogen.

RE: Yellowing Leaves Habanero/Bhut Under LED

Welcome to the forum Ctempz.

It looks like calcium deficiency and the light could be too intense as CTEMPZ mentioned.

I also use LED grow lights a couple of tall Trinidad Scorpion Plant have symptoms of Sunburned. These couple of leaves were closed to the lights. My LED tips/lense are "Epistar" it has Red 660nm and Blue445nm. I removed the lenses today and hang the LED a bit far from the plants.


Here is a link that might be useful: Calcium deficiency

RE: Yellowing Leaves Habanero/Bhut Under LED

What's your PH? The Ghost Pepper is a real diva and likes the Indian climate. Less water is more

RE: Yellowing Leaves Habanero/Bhut Under LED

From your pictures and descriptions, I THINK that it is a LIGHTING problem.

Assuming that you used the same medium and the same fertilizer, but getting two different kind on results/plants, the only variation can be the location under the lighting system. That is, one group is getting proper lighting and the other is not. IF it were due to nutrient deficiency, it should have been applicable to all the seedlings.
I think, SPOTLIGHT concentrated system is a challenge to provide a constant uniform light intensity. For this reason I light the fluorescent TUBE lighting (shop light system)

RE: Yellowing Leaves Habanero/Bhut Under LED

I've had the same problem pushing small plants straight to LED. I don't know what wavelengths your units are running, but assuming they are built for high PAR output, you'd be safer running under almost no nutrients or none at all on 20h on/ 4hr off for the first 8 node splits. Also, you are right about trying to get longer node distances by raising the lights.

If it were me, I would raise the lights, and do a cal-only nutrient "flush" for at least a week. Also, if you are using any "slow release fertilizer" soil.. Get rid of it if you are also nute-ing in your water. Ph should be around 6.2-6.5.

Good luck

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