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Am I using too much nitrogen?


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  #21  
Old 10-26-2009, 07:17 PM
Errol Errol is offline
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I guess you can go solo from here... but in case you have further questions, do not hesitate to rattle my bamboo cage!
Hello Luches,

Just a quick rattle of the cage! I came across this quote recently -
Quote:
Crop demand for nutrients changes through the season. Small amounts of nutrients are needed early, then the demand increases as the crop grows, especially after several clusters of fruit have been set on the plant. A common problem comes early in the season when plants become too vegetative (bullish) from too much N. The bullish growth distorts the leaves and stems, causing cracks and grooves in the stems. These openings are excellent entry ports for decay-causing organisms such as soft rot. Bullish plants usually produce misshapen fruits often with significant amounts of blossom-end rot and cat-facing. Keeping the N level low (60 to 70 parts per million) early in the season helps eliminate bullishness.
Does this mean that one should maybe keep EC down around the 0.9 or 1.0 mark until the plants begin to show signs of fruiting? I've had the occasional case of blossom end rot in tomatoes, but it's never been a real problem. I'd be interested in your comments.

Cheers,

Errol

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  #22  
Old 10-27-2009, 03:47 AM
Luches Luches is offline
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Originally Posted by Errol View Post

Just a quick rattle of the cage!
You're always welcome!

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Crop demand for nutrients changes through the season. Small amounts of nutrients are needed early, then the demand increases as the crop grows, especially after several clusters of fruit have been set on the plant. A common problem comes early in the season when plants become too vegetative (bullish) from too much N. The bullish growth distorts the leaves and stems, causing cracks and grooves in the stems. These openings are excellent entry ports for decay-causing organisms such as soft rot. Bullish plants usually produce misshapen fruits often with significant amounts of blossom-end rot and cat-facing. Keeping the N level low (60 to 70 parts per million) early in the season helps eliminate bullishness.
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Originally Posted by Errol View Post
Does this mean that one should maybe keep EC down around the 0.9 or 1.0 mark until the plants begin to show signs of fruiting? I've had the occasional case of blossom end rot in tomatoes, but it's never been a real problem. I'd be interested in your comments.
I don't agree with what is said (by whom ever) in that quote, because it's in fact very contradictory. I guess it's a combination of a false cause and a slippery slope: "if I reduce nitrogen from early growth stage, I'll not deal with BER later" is just a logical fallacy par excellence. The sun doesn't go down because we've turned on the street lights either, or does it?

1. First of all, we falsely believe (sometimes) that plants always take up what we feed them with a nutrient solution, just like chicken, cats or dogs. But osmosis is more complicated than mammal feeding and digestion. Plants take up a. what they need, b. choose from what there actually is in a nutrient solution, - and finally c. what the process of (rather complicate) osmosis allows them to take up in condition X. But In case there is too little nitrogen in a solution, plants my take it up very quickly and perhaps the PH will change and the nutrients will be unbalanced. That's what will happen basically and repeatedly...

2. BER is not caused by bullish growth all along the season or over time, but actually happens only A. with fruiting stage B. due of a lack of adequate calcium transport (which could either be caused by a actual lack of Ca, or a problem due to immobility of Ca.) and finally C. due to high temperature which leads to high plant metabolism and excessive vegetative growth. What actually happens when BER occurs, is that due to (temporary or sudden) heat, plant metabolism increases drastically but the immobile element Ca isn't transported and delivered quick enough to the tomato fruit. Bullish- or excessive vegetative growth itself is (or can be) partially responsible though, as huge amounts of N and Ca are consumed here. And hence there is not enough (slow moving) calcium available (left) for a healthy development of the tomato fruit.

3. Nitrogen levels as low as 60-70 ppm in the early season (as quoted) do not prevent BER for 2 reasons. A. most of the calcium provided in any nutrient solution comes necessarily from calcium nitrate. Thus, to provide enough calcium, we anyway need to keep Nitrogen at a certain level. B. BER doesn't happen at the early state nor in the middle nor later, but actually only when fruits are developing. That is why (as far as N-levels are concerned) we need to not exceed 150 ppm at any time - but actually neither at fruiting stage.

4. To prevent BER with tomato, the nutrient solution has to:

A. not exceed Nitrogen levels of 140-160 ppm during any stage
B1. contain enough calcium (140-160 ppm) all along.
B2. Supplementary calcium can be provided (max 0f 15-20%) through CaCl
C. temperature has to be kept under 34- (max 37C) for best oxygenation and uptake (of calcium)
D. PH should be (especially at fruiting state) around 6.5 or slightly over (also for best uptake of calcium which decreases gradually under 6.5).

5. One generally tends to confuse concentration of a nutrient (EC) and ppm content of each element. Imagine an Energy Drink that is too sweet for your taste. You would simply dilute it 50/50 with mineral water but actually drink only one glass (half of it) - what will you get? Half of the sugar (or substitute) of course, but also only half of the sodium, magnesium, potassium and all other salts and trace elements. As a sub-consequence, your lack of minerals in your "system" would not be topped up adequately, but only get half as much as recommended by nutrition science!

Have a closer look at the chart I provided earlier (in another thread) and which describes a rather low feeding, step by step feeding strategy worked out by research at the University of FLORIDA (not California).


Now take the 5th cluster formula and cut it in half (as in using half strength) . You'll end up with 75 ppm of Nitrogen, but only 75 ppm of Ca, 25 P, 25 Mg and half of the Fe and all other trace elements. And while N-content may be OK for seedlings and small plants, all of the other will simply not be sufficient for very long!

I know this is kind of a cross between a no-brainer and high level nutrient science, but that's actually how it looks and finally works!

Appendix:
1. Tomatoes that are grown in cooler climates or kept cool with artificial help are less prone to BER, because very high metabolism and too excessive growth (due to heat) are less to be expected.

2. Calcium supply can be supplemented with foliar spray of CaCl as a preventive cure while the use of foliar spray as treatment (in case of outbreak) cannot actually cure BER.

3. Some strategies prevent excessive growth by pruning lateral shoots and even other parts of the foliage. It is said that only the foliage located close to the fruit cluster can deliver (or complement) nutrients to the fruits, - any others are actually useless from a physiological point of view. Which is certainly true for calcium anyway, as it moves too slowly (as learned earlier).

4. Some tomato cultivars are more prone to BER than others. There are even special greenhouse varieties (Holland) that tolerate extra high feeding (with much higher Nitrogen levels as well) and "bullish" growth and heat, without being affected (easily) by BER. Unfortunately these varieties tend to lack other qualities like originality or taste.

Last edited by Luches; 10-27-2009 at 10:35 AM. Reason: corrected FLORIDA (from California)
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  #23  
Old 10-27-2009, 09:33 AM
Errol Errol is offline
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I don't agree with what is said (by whom ever) in that quote
Here's link to the quote if you wish to have a look at the full article. Being a layman I won't enter into the debate!

HS796/CV216: Nutrient Solution Formulation for Hydroponic (Perlite, Rockwool, NFT) Tomatoes in Florida

Anyway, thanks for you comments. You've convinced me to stick with the mix you suggested before and keep the EC at 1.8 period. I've managed, after a surprisingly wide search to find a supplier in Victoria who will sell me a manageable quantity of calcium chloride without charging the earth. So it will shortly be possible to introduce a Ca supplement to the nutrient.

You are extraordinarily knowledgeable on the subject of plant chemistry and your comments on this thread have made lots of sense and expanded my own knowledge quite a bit. One thing I think I've learned is to be a little more careful feeding my plants. In the past I've pretty much tossed in roughly equal measures of Hydrosol and calcium nitrate and been happy to let the EC wander around between 1.5 and 2.5. I've now made up some carefully measured (by weight) stock solutions and will keep the EC close to 1.8. Hopefully there'll be some good results.

Were you able to find the photos I mentioned? They're in an album on this forum.

Best wishes,

Errol
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  #24  
Old 10-27-2009, 10:33 AM
Luches Luches is offline
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Quote:
Originally Posted by Errol View Post
Here's link to the quote if you wish to have a look at the full article. Being a layman I won't enter into the debate!

HS796/CV216: Nutrient Solution Formulation for Hydroponic (Perlite, Rockwool, NFT) Tomatoes in Florida
Now that is something and withal very, very funny - because the graphics I've posted previously are leaned on (actually are) the nutrient strategy of the UNIVERSITY OF FLORIDA, I've got lost in translation somewhere (as someone from another continent) and confused both. Let me check if at least I got it right in the other thread - and I'll correct it here afterwards!

But look, while I agree 100% with their actual nutrient strategy, which I recommend - I still can't agree with that rather anecdotic (quoted) introduction. It gives (at least could give) one a really wrong idea of the actual facts and doesn't match the strategy explained and shown later in the very same article. But then again I did a mistake here too, when I was "wrongly" anticipating that a "60-70 ppm N formula" actually was supposed to be some sort of a "half strength standard formula". Because (in their formula table) they truly respect the needed P, Mg, Ca, as well as all Micro nutrients in the required amounts. Although what I wrongly anticipated could serve you well to not make the mistake to wrongly anticipate the very same thing! Gotcha

No debate necessary here, I've had my part in that realm...

Quote:
Originally Posted by Errol View Post
Were you able to find the photos I mentioned? They're in an album on this forum.l
Nope - I still wasn't able to dig them up, could you kindly post a direct link - thanks!

PS: please also note that what is true in warm Florida climate, isn't necessarily true in Tasmania. You're better off with a bit stronger nutrient concentration over there. But I don't need to remind you that you shouldn't start your seedlings with 1.8, - but with some 1.2-1.3 EC as suggested initially, right!? As you can't follow a sophisticated step by step nutrient program as the one of U.o.F,- you need to compromise somehow...

Cheers,
Luches
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  #25  
Old 10-27-2009, 07:01 PM
Errol Errol is offline
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Here's the photo link, nothing to get excited about. You might notice the curl in the older tomato leaves. Happens every year and doesn't seem to worry the plants, but whether it's a sign of a deficiency I'm not sure.

http://www.hydroponicsonline.com/for...droponics.html

Cheers,

Errol
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  #26  
Old 10-28-2009, 04:44 AM
Luches Luches is offline
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Unfortunately: Invalid Album specified. If you followed a valid link, please notify the administrator

Edit: This soft is really starting to p. me off. I opened your user profile again to check if I did miss something the last 3 times I checked for those pics. No link to any album from there. I opened the picture section, no search option, no way to get to any user's album or pictures either. Only recent adds available! General search with Errol, album, no way to get to those pics either! Furthermore, you need to take care like hell to not hit any of the zillion google adds by mistake

Last edited by Luches; 10-28-2009 at 05:02 AM.
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  #27  
Old 10-28-2009, 08:48 AM
Errol Errol is offline
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Hmm, don't know what's happening........the link works fine when I try it this end. Here it is again.

http://www.hydroponicsonline.com/for...droponics.html

Don't lose any sleep over it though, it's just a few piccies of my setup and I doubt you'll learn anything new!

Errol
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  #28  
Old 10-28-2009, 10:50 AM
Luches Luches is offline
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Originally Posted by Errol View Post
Hmm, don't know what's happening........the link works fine when I try it this end. Here it is again.

http://www.hydroponicsonline.com/for...droponics.html
Sorry - no way (from this end), always the same error message - I tried with 3 different browsers!

Quote:
Originally Posted by Errol View Post
Don't lose any sleep over it though, it's just a few piccies of my setup and I doubt you'll learn anything new!
I won't, but it's not about learning something new actually, but I have a personal interest in what you were building there and if you did well about it.
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  #29  
Old 10-29-2009, 02:07 AM
Errol Errol is offline
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OK, that's a strange one. If you're happy to let me have an email address I'll send them to you direct if you wish. But we're all entitled to our privacy and anonymity on these forums and if you prefer not to, or can think of some other way to view them, that will be fine with me!
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  #30  
Old 10-29-2009, 02:31 AM
Errol Errol is offline
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I've changed the album type from private to public to see if that makes any difference to accessibility from your PC.
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  #31  
Old 10-29-2009, 02:42 AM
Luches Luches is offline
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Originally Posted by Errol View Post
I've changed the album type from private to public to see if that makes any difference to accessibility from your PC.
That did the trick - now I can find- and open it from your profile
Looks good, thanks!
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  #32  
Old 01-18-2010, 02:21 AM
Errol Errol is offline
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Default Just a followup

Hi there Luches,

Just a followup from the help you gave me some time ago. I've persevered (well, it wasn't hard ) with the changes you recommended to my formula and all is going very well indeed. I've noticed particularly that root crops (carrots and beetroot) seem to be developing earlier than usual. Strawberries are very flavoursome despite a lower EC (1.8) than in previous years. Tomatoes are colouring nicely and I'll be interested to see whether they have a good flavour too or whether I'll need to give them an occasional individual drink at a higher EC. All other crops (cucumber, beans, leeks, capsicum and silver beet are doing exceptionally well. We've had a warm summer in Tasmania this year and I guess that's helping.

Hope is all well in your neck of the woods.

Cheers,

Errol
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  #33  
Old 01-26-2010, 06:55 AM
Luches Luches is offline
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Glad to hear you doing fine with your culture (and with my recommendations) - that's for sure. Also good to have some clearly positive feedback for a change. I am actually growing tomatoes with this very same concentration of 1.8. And other setups with so called semi domesticated peppers and some local capsicum frutescens between 1.4 and 1.6 only. They're all doing very fine. My various seed amaranths seem to be happy with high potassium formulas as well.

I guess it wouldn't do any harm to feed your (or my) toms at a bit higher EC, but the question is indeed if they'd do better or taste better at that end of the equation. From my understanding it's (as mentioned earlier) genetics in combination with weather conditions, temperatures etc., that does 80% of the taste. To really be sure if there would be a difference, you'd have to run two very same setups near each other with different nutrient strengths. And then again I guess you'd need to go higher with one group, as I suspect there would not be much difference between 1.8 and 2.0 EC anyways, if ever there would be any.

Sorry for the delayed reply, I've been off duty for a while here, because of some rather pointless beefs
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  #34  
Old 05-05-2010, 02:23 PM
narul narul is offline
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Default Hydroponic system

Hi, I am curious to know the Hrdroponic system you are using if possible a little sketch or photograph.You have said laundry buckets! As a beginner, your reply is valuable to me.Thank you.
narul
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  #35  
Old 10-28-2013, 09:16 AM
Errol Errol is offline
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Red face Apologies

Dear Narul,

My sincere apologies. I had no idea you had requested a reply from me and you're probably thinking what a rude sod I am for not replying. In point of fact, I has assumed the discussion between Luches and I had come to an end and I didn't check this site again until tonight (almost 4 years later!) when I wanted to confirm some quantities Luches had suggested.

If you're still interested in any information I can provide, even if it's years after you initially requested it, I'm only too happy to oblige.

Once again, (very) belated apologies.

Grant (Errol)

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