Urea fertilizer - outstanding results

[polyantha]

Is there something wrong with the roots now?
How have they changed?
How do they need to be improved?

There is nothing wrong, if you mean wrong like "lots of dead roots". They are just not growing new root rips so easily. I didn' repot since using urea, but I did yesterday to be able to describe root growth with urea. So as a conclusion I can say it is good for vegetative growth, but not for root growth.
I used to get very vigorous fleshy roots when I gave very little fertilizer, but now root growth slowed down. This definitely must be because of the urea fertilizer, because I didn't repot in this time.
Overall growth has to be improved: At best there are lots of new roots filling the pot.

 

[gonewild]

So this brings us back to the question: Is darker green better than lighter green?

Great pics thanks for the effort to list them.
The pictures show the exact reason I ask the question about whether the pictures I linked were dark green. Light green, medium green, dark green are all subjective.

My perspective is that most of the leaves in the links you listed have medium green foliage. I'm not talking about the dark green part of mottled leaves. i am talking the overall color of the leaf based on what it looks like.
If you look at a leaf and ask yourself can this leaf be a lot darker aand you think "yes" then ask yourself can it get a lot lighter and still be green and you answer yest.... the the leaf is a medium green.

Leaf color changes with the mood of the plant a lot like skin color on a human. A doctor can look at the shade of your skin and see symptoms... and a horticulturist can do the same with leaf color.

If we assume a healthy normal leaf is medium green then we have a base reference point to use as a comparison. If the leaf color has shifted one way or the other we know what cultural conditions may need to be corrected.

I see the healthy wild plants in your pictures as medium green and I adjust my evaluation depending on the leaf type. Certainly mottled leaf paphs have parts of their leaves very dark, but also have very light parts as well, so you have to look at the overall shade compared to a norm.

If your plants have been growing very pale and you change something and they get darker green you may think " they are a nice dark green now" when in fact they have only changed to medium green. This subjective color evaluation makes it difficult to diagnose a culture problem when someone says my plants have dark leaves.

In the original pictures Polyantha posted that she described as nice dark green I see one plant as being dark green and the other as being medium green. Neither do I consider as "nice dark green". Both show nutrient or environmental issues than can be improved on. The dark plant is too dark and the other medium green leaves are not uniform in color and appear blotchy.

 

[gonewild]

There is nothing wrong, if you mean wrong like "lots of dead roots". They are just not growing new root rips so easily. I didn' repot since using urea, but I did yesterday to be able to describe root growth with urea. So as a conclusion I can say it is good for vegetative growth, but not for root growth.
I used to get very vigorous fleshy roots when I gave very little fertilizer, but now root growth slowed down. This definitely must be because of the urea fertilizer, because I didn't repot in this time.
Overall growth has to be improved: At best there are lots of new roots filling the pot.

Did you take pictures of the roots?

This is why I was asking questions and not making conclusions until we know your facts. I know from past personal use that when UREA is used as a main nitrogen source at first overall growth looks quickly improved. That's because we can see the leaf color change. But we can't see the roots slow down.

I'll comment more later.

 

[polyantha]

The dark plant is too dark and the other medium green leaves are not uniform in color and appear blotchy.

Praestans has to be dark if you ask me. Nothing special actually, there are other praestans in my collection and they are among the darkest of my plants. Even without urea.

 

[Ozpaph]

Thanks for the great photos but its almost impossible to tell how bright it is without some reference - the camera exposes to mid-gray.
Also that's the tropics when light intensity is strong and near vertical for most of the year, unlike most of us below the tropics.

 

[gonewild]

There is nothing wrong, if you mean wrong like "lots of dead roots". They are just not growing new root rips so easily. I didn' repot since using urea, but I did yesterday to be able to describe root growth with urea. So as a conclusion I can say it is good for vegetative growth, but not for root growth.
I used to get very vigorous fleshy roots when I gave very little fertilizer, but now root growth slowed down. This definitely must be because of the urea fertilizer, because I didn't repot in this time.
Overall growth has to be improved: At best there are lots of new roots filling the pot.

Do the current roots all have active growing tips after this time under UREA nitrogen?

 

[gonewild]

Thanks for the great photos but its almost impossible to tell how bright it is without some reference - the camera exposes to mid-gray.
Also that's the tropics when light intensity is strong and near vertical for most of the year, unlike most of us below the tropics.

Also every camera brand produces a different shade of green. It's not just in the digital process it is in the glass of the lens. If you do a side by side comparison between top quality Canon and Nikon lenses you will see each one renders colors differently. So you are correct trying to compare foliage color over the internet is not very accurate at all. And yes tropical sun is very different. When I look at wild orchids I always look at leaf color and I rarely see one with what I would call dark green leaves. Granted I am not in Asia looking at paphs but I bet it is not much different there.

 

[gonewild]

I don't want to change the subject, but are there special formulations to get good root growth? Because that is the only thing that was better on previous fertilizers and since my plants have many new growths now, I could focus on the roots the next months.

The option is to find the correct balanced fertilizer for your growing conditions. It's not really possible to focus on improving a selected part of the plants anatomy. Doing so will alter the rest of the plant.

Since you feel that your nitrate fertilizer was not growing your plant tops well but did grow your roots well and now see the reverse with UREA you should realize that there is something out of balance.
It could be as simple as using a combo of both nitrate and ammonia but that may not be the route to the best growth.

The ideal thing is first to figure out why the nitrates failed, because they should grow a beautiful plant.
The only way to figure it out is to evaluate all your conditions involving water and media.
Do you know the pH of your water and media?
Do you know the buffer capacity of your water?
How much nitrate did you apply, ppm and frequency?
what is in your media?
What temperature are your plants in?
Does the media get really hot or cold?

Questions like these will lead to a solution.

 

[gonewild]

When someone gives you a quick answer about a plant nutrient problem by looking at a photo without asking questions don't believe it. They have no idea what the illness is yet they prescribe a treatment, would you expect that from your human doctor? Plants are not mechanical machines or electronics that have a limited number of things that can break. plants are complex living creatures that are subject to an infinite number of possible maladys.

 

[cnycharles]

Question was stated about root growth, and was pointed out that when weak fertilizer was used, lots of fleshy roots grew but seemed to stop after starting urea. Could be simple: little fert, plant goes looking and makes roots. At this time, urea is used and plant has tons of fert and decides it needs no more roots and just sits soaking up fert

Simplistic answers, and could be many others as well

 

[gonewild]

Question was stated about root growth, and was pointed out that when weak fertilizer was used, lots of fleshy roots grew but seemed to stop after starting urea. Could be simple: little fert, plant goes looking and makes roots. At this time, urea is used and plant has tons of fert and decides it needs no more roots and just sits soaking up fert

Simplistic answers, and could be many others as well

Could be as simple as that! (If the plant is lazy)
Will that still apply if the UREA was also applied in weak amounts?
I assume the UREA was applied at the same dose as the nitrate.

 

[cnycharles]

Never know how hormone levels affect root growth based on nutrient types and levels, we all know that for many plants you overwater and they produce few roots; mete out water during growth and many plants produce more roots and longer to satisfy need. Possible correlation to feed types or quantity and growth/lack of

 

[NYEric]

Scary! This thread has a life of its own!

 

[Stone]

A possible reason that many people complain of ''not....yellow....but....not....so....green'' leaves with nitrate feeding is that they may simply not take it up or use it as effeciently as ammonium.
Many plants from acid evnvironments (where most orchids come from) prefer ammonium to nitrate.
Here is an example:http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2802997/
Yet another case for including Urea/ammonium for at least some of the N
There are reasons for not using either exclusively

 

[gonewild]

A possible reason that many people complain of ''not....yellow....but....not....so....green'' leaves with nitrate feeding is that they may simply not take it up or use it as effeciently as ammonium.
Many plants from acid evnvironments (where most orchids come from) prefer ammonium to nitrate.
Here is an example:http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2802997/
Yet another case for including Urea/ammonium for at least some of the N
There are reasons for not using either exclusively

Do you have any info of what type of nitrogen is leached in throughfall that you have referenced as the main nutrient source for wild orchids?

The Tea research is interesting.Some thoughts... I wonder how much it applies to orchids since Tea is extremely acid dependent like azelias and basically won't grow without a strong acid soil? Most orchid species come from environments with soil water closer to pH neutral. In this tea trial they do the experiment hydroponic so solid media factor is removed from the interface of plant to nutrient.

 

[orcoholic]

I don't want to change the subject, but are there special formulations to get good root growth? Because that is the only thing that was better on previous fertilizers and since my plants have many new growths now, I could focus on the roots the next months.

I'm not aware of any fertilizers that concentrate on root growth. However, repotting and not watering too much should help encourage good root growth.

IMO you need to give the roots a "reason" to grow. Giving too much water and fertilizer keeps the roots from having to grow because everything the plant needs is right there. Watering less frequently makes the roots grow because they need to go deeper, or get longer, to get more water to support the upper growth.

 

[SlipperFan]

I like that thinking!

 

[Stone]

Do you have any info of what type of nitrogen is leached in throughfall that you have referenced as the main nutrient source for wild orchids?

Only going by memory but I think in at least one case (possibly China?) the NH4 was higher than NO3 but they are not often ditiguished in those studies.

Most orchid species come from environments with soil water closer to pH neutral.

Well as far as epiphytes go the water coming off the branches in Ecuador around Odontoglossums was pH4. (about the same as Azaleas and cammelias enjoy) So we can assume anything above ground is probably mostly acididic. In sandstone and volcanic or non limestone areas, the pH is typically around 5.5 or so. Sanderianum habitat was 7 and Rick said the kovachii habitat was around 6.8 I think. So it looks like slightly acid to neutral for the limestone species only. (if that) Xavier mentioned bellatulum growing in a very acid substrate also.
I would bet that the pics of the Paphs which were posted by paphioboy were growing in an acid substrate.

 

[Stone]

These are the first pics of emersonii in habitat I have seen!
http://www.bloggang.com/viewblog.php?id=taurus&group=3&page=2

 

[orcoholic]

Polyantha,

Using the smallest pots possible will also encourage root growth.