A 'short read on 'stretch.

Flowki

Flowki

Well-Known Member
http://www.pthorticulture.com/en/training-center/relationship-between-fertilizer-plant-stretching/

''Phosphorus: Dr. Nelson then looked at phosphorus. In his research, he formulated fertilizers with different levels of phosphorus, but kept the nitrogen ratios and all other nutrients the same. The results showed a significant difference in the height of bedding plants in which those fertilized with a high phosphorus fertilizer were taller than those given a low phosphorus fertilizer. The conclusion was obvious; it is not the form of nitrogen in a fertilizer that influences stretching and plant growth, but it is the amount of phosphorus.


This conclusion makes sense as symptoms of phosphorus deficiency include plant stunting and darkening of the leaves as seen in the following picture. These symptoms are good quality attributes for most plants; however, prolonged phosphorus deficiency can progress into foliar necrosis and deterioration of crop quality. A water soluble fertilizer should provide a minimum phosphorus level (P2O5) of 10-15% of the nitrogen concentration (i.e. fertilizers with analyses such as 20-2-20 or 20-3-20). Some plug crops may prefer higher levels of phosphorus and may benefit from an analysis such as 20-5-20. Fertilizers such as 20-10-20 or 20-20-20 provide more phosphorus than crops need, but other than plants being taller; these fertilizers do not have a negative impact on crops.''

 
testiclees

testiclees

Well-Known Member
Very
Flowki said:
http://www.pthorticulture.com/en/training-center/relationship-between-fertilizer-plant-stretching/

''Phosphorus: Dr. Nelson then looked at phosphorus. In his research, he formulated fertilizers with different levels of phosphorus, but kept the nitrogen ratios and all other nutrients the same. The results showed a significant difference in the height of bedding plants in which those fertilized with a high phosphorus fertilizer were taller than those given a low phosphorus fertilizer. The conclusion was obvious; it is not the form of nitrogen in a fertilizer that influences stretching and plant growth, but it is the amount of phosphorus.


This conclusion makes sense as symptoms of phosphorus deficiency include plant stunting and darkening of the leaves as seen in the following picture. These symptoms are good quality attributes for most plants; however, prolonged phosphorus deficiency can progress into foliar necrosis and deterioration of crop quality. A water soluble fertilizer should provide a minimum phosphorus level (P2O5) of 10-15% of the nitrogen concentration (i.e. fertilizers with analyses such as 20-2-20 or 20-3-20). Some plug crops may prefer higher levels of phosphorus and may benefit from an analysis such as 20-5-20. Fertilizers such as 20-10-20 or 20-20-20 provide more phosphorus than crops need, but other than plants being taller; these fertilizers do not have a negative impact on crops.''
Click to expand...
These are the paragraphs before the ones you [posted

Very interesting.

Nitrogen Forms: It has been long thought that the form of nitrogen used to fertilize a plant influenced plant stretching and quality. Ammoniacal nitrogen has been thought to cause plant stretching, increase leaf size and produce soft growth; while nitrate nitrogen produces compact, firm growth with smaller leaves. Experientially this seems to be true. For example 20-10-20, which has 40% ammonium and 60% nitrate, can promote stretching, larger leaf size and softer overall growth compared to 13-2-13 which is 6% ammonium and 94% nitrate. However there is another variable; if both fertilizers are applied at the same nitrogen application rate; 20-10-20 provides more than three times as much phosphorus as 13-2-13.

Traditionally fertilizers that have a high ratio of ammoniacal nitrogen also have higher levels of phosphorus due to their formulation with ammonium phosphate. Fertilizers with higher ratios of nitrate usually have little to no phosphorus content since the calcium nitrate they are formulated with can form precipitates with phosphate. So is the nitrogen source the factor in plant stretching?

Dr. Paul V. Nelson, Professor Emeritus of NCSU and his team, conducted research with various bedding plants in which he applied fertilizer with different ratios of ammoniacal to nitrate nitrogen, while keeping all other nutrients the same. The results demonstrated that there was little difference in plant growth. Based on these results, the old idea that ammonium causes plant stretch and nitrate produces short, more tone plants was not true. Dr. Nelson concluded that the form of nitrogen has little influence on plant height and growth.
 
Flowki

Flowki

Well-Known Member
testiclees said:
Very


These are the paragraphs before the ones you [posted

Very interesting.

Nitrogen Forms: It has been long thought that the form of nitrogen used to fertilize a plant influenced plant stretching and quality. Ammoniacal nitrogen has been thought to cause plant stretching, increase leaf size and produce soft growth; while nitrate nitrogen produces compact, firm growth with smaller leaves. Experientially this seems to be true. For example 20-10-20, which has 40% ammonium and 60% nitrate, can promote stretching, larger leaf size and softer overall growth compared to 13-2-13 which is 6% ammonium and 94% nitrate. However there is another variable; if both fertilizers are applied at the same nitrogen application rate; 20-10-20 provides more than three times as much phosphorus as 13-2-13.

Traditionally fertilizers that have a high ratio of ammoniacal nitrogen also have higher levels of phosphorus due to their formulation with ammonium phosphate. Fertilizers with higher ratios of nitrate usually have little to no phosphorus content since the calcium nitrate they are formulated with can form precipitates with phosphate. So is the nitrogen source the factor in plant stretching?

Dr. Paul V. Nelson, Professor Emeritus of NCSU and his team, conducted research with various bedding plants in which he applied fertilizer with different ratios of ammoniacal to nitrate nitrogen, while keeping all other nutrients the same. The results demonstrated that there was little difference in plant growth. Based on these results, the old idea that ammonium causes plant stretch and nitrate produces short, more tone plants was not true. Dr. Nelson concluded that the form of nitrogen has little influence on plant height and growth.
Click to expand...
Yes, I was going to ask a question if more ammo during some stage of veg to increase leaf size would be beneficial later for flower photosynthesis. Was not so sure on the validity of the link.

If it's even somewhat true then perhaps it's ironic to have more P with ammo in veg than P in bloom.
 
testiclees

testiclees

Well-Known Member
Flowki said:
Yes, I was going to ask a question if more ammo during some stage of veg to increase leaf size would be beneficial later for flower photosynthesis. Was not so sure on the validity of the link.

If it's even somewhat true then perhaps it's ironic to have more P with ammo in veg than P in bloom.
Click to expand...
I didn't question the link. I wasn't suspicious since it didn't seem to bear on the efficacy of promix products. Is there a red flag some where?

I equate the really large leaves with soft growth. Not always, but often, for me, soft growth burns easily under high irradiance and it invites sap sucking insects. I try to encourage sturdy, hardy growth with light feeding and high ppfd, good air movement, reasonable vpd range.
 
Flowki

Flowki

Well-Known Member
testiclees said:
I didn't question the link. I wasn't suspicious since it didn't seem to bear on the efficacy of promix products. Is there a red flag some where?

I equate the really large leaves with soft growth. Not always, but often, for me, soft growth burns easily under high irradiance and it invites sap sucking insects. I try to encourage sturdy, hardy growth with light feeding and high ppfd, good air movement, reasonable vpd range.
Click to expand...
No no, not saying you did question it. I don't know much about much so was not trying to lay the link down as if it was solid facts. So ammo is likely not a good thing then?. Unless we are talking about the US cops ;p, perhaps not a tasteful joke at current although it's unlikely it could be at any given time.
 
testiclees

testiclees

Well-Known Member
Flowki said:
No no, not saying you did question it. I don't know much about much so was not trying to lay the link down as if it was solid facts. So ammo is likely not a good thing then?. Unless we are talking about the US cops ;p, perhaps not a tasteful joke at current although it's unlikely it could be at any given time.
Click to expand...
Lol i was wondering if you had a concern with he info at the link!
 
Flowki

Flowki

Well-Known Member
testiclees said:
Lol i was wondering if you had a concern with he info at the link!
Click to expand...
I've got it in my head, likely from reading other comments and so forth that N is the reason for stretch, particularly around flip. After seeing that link it seemed worth punting to see the responses.

A further question, would a balanced mix of Nitrate+ammo offer the best of both worlds?. I often wonder why plants typically done organic style have much bigger, thicker and better looking leaves/stems regardless of soil bio. Maybe it's silly to assume ammoN is the simple difference while also being on the assumption organic uses mostly that. My understanding was that ammo is not accessible to roots in hydro ( A wrong conclusion from me).

I read up a little more and it seems Nammo is extremely beneficial but at the same time very dangerous in the wrong amount, to the point agriculturists are scared to play with it. Well, that's the basic jist of the link anyway. One stand out point was that it increases the uptake of P. It also mentions that N nitrate increased soil ph while Nammo reduces it. I guess I understand now why some hydro ferts state they have a little Nammo to regulate ph.

https://books.google.co.uk/books?hl=en&lr=&id=fi_LBAAAQBAJ&oi=fnd&pg=PA157&dq=ammonium+nitrogen+and+plants&ots=QSWkdS_g9X&sig=SF5cJLuCtIttTZ2j8LRgr6ZFdfI#v=onepage&q=ammonium nitrogen and plants&f=false
 
Last edited:
You must log in or register to reply here.
Top