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Help! Hydroponic tomato deficiency

Posted by jamesvlad (My Page) on
Wed, Aug 18, 10 at 14:21

Hello everyone. I have a hydroponic tomato, but it seems to have a deficiency that I can´t identify...maybe someone can help me.

The nutrient solution composition is:
N 181
P 51
K 267
Ca 123
Mg 42
S 42
using tap water (about 40 ppm of calcium) phosphoric acid as phosphorus source, and some sulfuric acid to adjust pH.

and micronutrients (Fe, Cu , Zn, B, Mo, Mn) but I´m not sure about the concentrations

This is the picture


Follow-Up Postings:

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RE: Help! Hydroponic tomato deficiency

Sorry!!

This is the link of the picture:

http://www.flickr.com/photos/25020806@N08/4904706243/


By the way...do you know how to insert images in this forum?

Thanks in advance!


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RE: Help! Hydroponic tomato deficiency

What is the picture? I see no picture.

I assume your N is NO3?

Note that things other than deficiencies can cause problems. Last year I had a problem with tom survival, and after a lot of experimentation, I determined that it was a phytotoxic reaction to the insecticidal soap I was spraying.


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RE: Help! Hydroponic tomato deficiency (2)

Ah, I see you fixed it. You add images with <img src="http://YOUR_URL">


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RE: Help! Hydroponic tomato deficiency

Thank you karenkei. Yes my N is NO3 only (Ca(NO3)2, KNO3 and NaNO3, HNO3). I use only the nutrient solution, no more things.

This is the image:


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RE: Help! Hydroponic tomato deficiency

Hello Jamesvlad,

I once had similarly looking plants when doing some experiments with hydrogen carbonate ion concentrations. If you can indeed provide all your 51 ppm of P as phosphoric acid and then you need to add sulfuric acid on top of that to reach a pH around 5.5-6.5 then the problem might be an excess amount of carbonate in your water.

The lack of any chlorosis suggests that there are no micro nutrient or N deficiencies but the leaf deformation and the similar appearance when compared with my experiment plus your description makes me believe that this is the problem. I would suggest you prepare your solution with RO or distilled water from now on and share your results with us once you do this.

I hope this helps !

Best Regards,

Daniel


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RE: Help! Hydroponic tomato deficiency

Thank you danielfp. Again, you´re right. The hydrogen carbonate concentrations is high. I´ve been using distilled water, and the toxicity is disappearing. The leaf are returning to normal, I´m going to take another photo and insert the picture in two or three days.


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RE: Help! Hydroponic tomato deficiency

10 days ago I changed the nutrient solution (without bicarbonate), I now this is the result:

As you can see, the tomato is returning to normal.

So, for anyone who may have the same problem: the excess of bicarbonate ion could be the problem.

Thanks again danielfp and karenkei.


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