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Author Topic: Problems with growing citrus trees indoors under LED grow lights  (Read 564 times)

Dogjamboree

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Hi,

I'm growing several types of dwarf citrus trees in my grow tent during the winter (a. Long with other types of plants) under 2 LED lights and experiencing some problems. First, the types of trees are Meyer lemon (2), kaffir lime, bears lime, and Australian lime.

The problems I'm experiencing are pretty much the same for all the trees (except for the Australian lime which is newer) - - leaves are looking bleached and mottled, nothing like the way a nitrogen deficiency looks, and the texture of the leaves is no longer smooth but rather coarse and rough. None of the trees had these problems before going into the grow tent and I'm fairly certain the problem is related to the grow lights. The thing that's really puzzling me is I have the lights further away than they should need to be and other full-sun plants like avocado, fig trees, birch tree (don't ask) are all fine. For those of you familiar with PAR light meters, I have an apogee quantum flux meter which is giving me readings of around 250 umols around the top of the plant canopy. Direct sun measures in the range of 800-2000 umols, and I have other plants closer to the light with no ill effects. Also, I should mention that I run the lights 18 hours on / 6 off. Anyone know if this is too little rest time for citrus trees?

I will post pics of the leaves soon but have visual impairments using computers so doing this without my eyes and having my wife help me later to post the pics (also please pardon any weird spellings, etc). I should also mention the one of the Meyer lemon lost 3 leaves and they all had light brown or yellow spots on them. I'm not even going into my whole regimen of fertilization, etc, because I highly doubt this is a nutrient / micronutrients issue as it would be a weird coincidence if everything went to hell at the same time when they were all fine before. I'm very conscientious with watering, meaning I only water when it's needed and I've got several ways of figuring this out (bamboo skewers, how the soil feels, container weight, etc). Humidity is always around 60% and temperature is around 80 degrees. Airflow is good, with internal fan circulating and intake replenishing air several times per hour.

I should also mention that the LED's are the newest technology on LED on chip, which produces mostly red / blue light with some infra-red and uv light thrown in for good measure. One of my biggest concerns is whether citrus might react different to this spectrum combo than other plants do. Anyway, sorry for the rambling post, part of the problem with using this software to use computers / phones is I have to write from memory and can't really revise.

Thanks in advance,

Frank

SoCal2warm

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Re: Problems with growing citrus trees indoors under LED grow lights
« Reply #1 on: March 21, 2019, 01:51:48 AM »
The problems I'm experiencing are pretty much the same for all the trees - - leaves are looking bleached and mottled, nothing like the way a nitrogen deficiency looks,
Very likely due to excessively moist soil conditions.

In a container it can be very difficult to consistently maintain the soil moisture level in the right range. The soil cannot be allowed to completely dry out, but too much prolonged moisture will inevitably start leading to root rot, and symptoms will show up in the leaves.

It might also be possible you may have too much light, but I would think that unlikely.

I have no problem growing seedlings under LED lights. I use one "100 watt equivalent" (13 Watt) LED bulb for each 2 by 2 foot area, approximately. 5000K.

The ones in larger containers do not look as well, some leaf yellowing, though occasionally they'll put out outshoots of growth.

I feel probably the most optimal thing would be to mix red/blue LED with white LED.

SoCal2warm

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Re: Problems with growing citrus trees indoors under LED grow lights
« Reply #2 on: March 21, 2019, 01:55:06 AM »
I would also check to make sure you don't have a problem with spider mites, which is a very common problem growing inside.

If you do, you will periodically bring them outside about every 3 weeks and thoroughly spray (including the undersides of the leaves) with a solution of spinosad and insecticidal soap. The first time you should spray, then spray again in 5 days, then spray once more 5 days after that, just to make sure you get them all initially.

Millet

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Re: Problems with growing citrus trees indoors under LED grow lights
« Reply #3 on: March 21, 2019, 10:48:29 AM »
It is very difficult to determine problems without seeing good pictures of the tree.

hardyvermont

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Re: Problems with growing citrus trees indoors under LED grow lights
« Reply #4 on: March 21, 2019, 02:07:24 PM »
and the texture of the leaves is no longer smooth but rather coarse and rough.

That sounds like insects.  You are touching them or their frass.

luak

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Re: Problems with growing citrus trees indoors under LED grow lights
« Reply #5 on: March 21, 2019, 07:25:25 PM »
I converted from t8 to 48" led's in my shop, works pretty good for me.



Millet

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Re: Problems with growing citrus trees indoors under LED grow lights
« Reply #6 on: March 21, 2019, 08:43:37 PM »
Luak, your trees always look healthy.  You do a great job caring with them.

Sylvain

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Re: Problems with growing citrus trees indoors under LED grow lights
« Reply #7 on: March 22, 2019, 09:15:37 AM »
I just wonder what is:
 
  :)

luak

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Re: Problems with growing citrus trees indoors under LED grow lights
« Reply #8 on: March 22, 2019, 10:45:06 AM »
Silvain, referring to my setup, I plug in 5 led lights per timer for 12 hours.

Dogjamboree

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Re: Problems with growing citrus trees indoors under LED grow lights
« Reply #9 on: March 22, 2019, 02:05:18 PM »
Thanks for all the responses. I'm sure you would have figured it out faster with photos but I needed help with that. It's definitely spider mites, I discovered them yesterday. I spent yesterday cleaning out the grow tent and treating all the plants. Will continue to monitor obsessively. I'll add photos now in case its helpful to anyone. Thanks again.








lebmung

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Re: Problems with growing citrus trees indoors under LED grow lights
« Reply #10 on: March 23, 2019, 06:11:33 AM »
What is the pH of the soil? Could be a boron deficiency

BenjaminJohnson

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Re: Problems with growing citrus trees indoors under LED grow lights
« Reply #11 on: April 12, 2019, 02:25:14 AM »
Luak, how old are your trees?  They look great.

Sylvain

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Re: Problems with growing citrus trees indoors under LED grow lights
« Reply #12 on: April 12, 2019, 08:06:34 AM »
Dogjamboree, the three first photos don't show spider mites attack but the last one could (or has).

Radoslav

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Re: Problems with growing citrus trees indoors under LED grow lights
« Reply #13 on: April 12, 2019, 08:38:40 AM »
first and last picture show mites attack. Third is simply an old leaf, I think. Mites are big problem for indoor growing, they can kill the tree, it is a question of air humidity. The lower air humidity means more mites.

luak

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Re: Problems with growing citrus trees indoors under LED grow lights
« Reply #14 on: April 13, 2019, 02:56:52 PM »
My trees are different in age, start out with a Page mandarin 10 years, Cara Cara , Xie Shan,, Dream Naval 5 years, the newer ones 2017 and 2018 about 22 of them, these are grafted during the 2017 and 2018 winters. These new ones are all fruiting now.

 

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