Why are some plants in the same row yellow?
I have been growing kale for almost 10 years, but lately most of my plants turn yellow and most of those eventually die. See attached photo. I don't see how it could be a nutrient or pH problem when some plants in the same solution are healthy. I'm also having a hard time starting new plants as the vast majority of new seedlings start out great and then, after a couple weeks, turn yellow and die. Any ideas?
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pepperhead212
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- Location: Woodbury NJ Zone 7a/7b
The younger ones look nutrient deficient. Is this a flow by system? and what formula are you using.
One of the main issues I see is that it looks like you have kinds of plants and plants of different ages in the same system. Usually, you don't do this, The larger plants will suck up more of the nutrients because they have larger root systems. Normally, you put plants with similar nutrient needs that can use the same nutrient formula and plants of the same age using the same reservoir Unless you have a controller it would be difficult to meet the needs of different plants and different stages of growth.
One of the main issues I see is that it looks like you have kinds of plants and plants of different ages in the same system. Usually, you don't do this, The larger plants will suck up more of the nutrients because they have larger root systems. Normally, you put plants with similar nutrient needs that can use the same nutrient formula and plants of the same age using the same reservoir Unless you have a controller it would be difficult to meet the needs of different plants and different stages of growth.
I’m only growing Premier Kale with a few Cilantro plants (I think there is one dead seedling in the photo). For nutrients I’m using a formula optimized for curly Kale by research conducted by a university that I have forgotten. I have been using it for years and nothing has changed. I also tried draining the system and starting with fresh water, and that did not help. Sorry that the spreadsheet did not paste well, and I can't attach a spreadsheet.
Below is the formula:
grams
A - Calcium Nitrate (Tetrahydrate) Ca(NO3)2.4H2O 961.722
A - Iron EDTA Fe(EDTA) 14.198
A - Potassium Nitrate KNO3 475.712
B - Boric Acid H3BO3 2.165
B - Copper Sulfate (pentahydrate) CuSO4.5H2O 0.059
B - Magnesium Sulfate (Heptahydrate) MgSO4.7H2O 368.559
B - Manganese Sulfate (Monohydrate) MnSO4.H2O 1.055
B - Phosphoric Acid (30%) H3PO4 247.491
B - Sodium Molybdate (Dihydrate) Na2MoO4.2H2O 0.019
B - Zinc Sulfate (Dihydrate) ZnSO4.2H2O 0.114
N (NO3-) 237.722 -8.60% +/- 0%
K 242.983 3.40% +/- 0%
P 31 0% +/- 0%
Mg 48 0% +/- 0%
Ca 215.57 7.80% +/- 0%
S 63.634 -0.60% +/- 0%
Fe 2.5 -2.50% +/- 0.1%
Zn 0.05 0% +/- 8.8%
B 0.5 0% +/- 0.5%
Cu 0.02 0% +/- 16.8%
Mo 0.01 0% +/- 52.4%
Na 14.005 0% +/- 0%
Si 0 0% +/- 0%
Cl 5 0% +/- 0%
Mn 0.5 -9.40% +/- 0.9%
N (NH4+) 0 0% +/- 0%
Total 861.494
Below is the formula:
grams
A - Calcium Nitrate (Tetrahydrate) Ca(NO3)2.4H2O 961.722
A - Iron EDTA Fe(EDTA) 14.198
A - Potassium Nitrate KNO3 475.712
B - Boric Acid H3BO3 2.165
B - Copper Sulfate (pentahydrate) CuSO4.5H2O 0.059
B - Magnesium Sulfate (Heptahydrate) MgSO4.7H2O 368.559
B - Manganese Sulfate (Monohydrate) MnSO4.H2O 1.055
B - Phosphoric Acid (30%) H3PO4 247.491
B - Sodium Molybdate (Dihydrate) Na2MoO4.2H2O 0.019
B - Zinc Sulfate (Dihydrate) ZnSO4.2H2O 0.114
N (NO3-) 237.722 -8.60% +/- 0%
K 242.983 3.40% +/- 0%
P 31 0% +/- 0%
Mg 48 0% +/- 0%
Ca 215.57 7.80% +/- 0%
S 63.634 -0.60% +/- 0%
Fe 2.5 -2.50% +/- 0.1%
Zn 0.05 0% +/- 8.8%
B 0.5 0% +/- 0.5%
Cu 0.02 0% +/- 16.8%
Mo 0.01 0% +/- 52.4%
Na 14.005 0% +/- 0%
Si 0 0% +/- 0%
Cl 5 0% +/- 0%
Mn 0.5 -9.40% +/- 0.9%
N (NH4+) 0 0% +/- 0%
Total 861.494
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applestar
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- Joined: Thu May 01, 2008 7:21 pm
- Location: Zone 6, NJ (3/M)4/E ~ 10/M(11/B)
I thought what @imafan meant was that the big mature plants in the same system is sucking up all the nutrients?
I was envisioning same thing happening as when some tomato seedlings bully others in same cell tray by sneaking long roots into the neighboring cells either from top or bottom. I thought that would make sense.
How long do the roots of the bigger plants extend? The roots of the mature plants are likely to have more efficient osmotic pressure for nutrient uptake. Is there a way to take nutrient solution test samples from the yellowed plant rootzone?
I was envisioning same thing happening as when some tomato seedlings bully others in same cell tray by sneaking long roots into the neighboring cells either from top or bottom. I thought that would make sense.
How long do the roots of the bigger plants extend? The roots of the mature plants are likely to have more efficient osmotic pressure for nutrient uptake. Is there a way to take nutrient solution test samples from the yellowed plant rootzone?
I forgot to say, thanks everyone for helping me figure this out!
This is a continuous flow system on 3 shelves, one of which is in the photo. I’m using a common reservoir for all tubes and shelves. I have yellow dying plants in rows that have no older plants, and I have green health plants downflow of large old ones. So, I can’t see how the problem could be proximity to old plants.
As for nutrients, I achieve the right concentration by adding 70 ml each of A and B to 15 l of water and that is the only water I add to the system, and I have been doing so for years. It works so well, I have stopped trying to monitor PPM or EC. I tried doubling the nutrients for one filling and did not see any difference, maybe I did not wait long enough? Rich now my stats for EC are 4M Ohm/cm with volt meter, and 8228 micro S/cm, and 4100 PPM all at 21.7 Celsius. My target EC is much higher at 1.9 mS/cm, but I do not trust these numbers.
As you are helping me think about this, I never had a problem until I allowed some plants to over grow. The theory that the massive plants are sucking up all the nutrients does not seem to explain why some plants managed to start from a seedling and grow healthy. However, now that I think aobut it, it is less than 10% (maybe 2 %) of seedlings that grow healthy now, so maybe they are some kind fluke?
This is a continuous flow system on 3 shelves, one of which is in the photo. I’m using a common reservoir for all tubes and shelves. I have yellow dying plants in rows that have no older plants, and I have green health plants downflow of large old ones. So, I can’t see how the problem could be proximity to old plants.
As for nutrients, I achieve the right concentration by adding 70 ml each of A and B to 15 l of water and that is the only water I add to the system, and I have been doing so for years. It works so well, I have stopped trying to monitor PPM or EC. I tried doubling the nutrients for one filling and did not see any difference, maybe I did not wait long enough? Rich now my stats for EC are 4M Ohm/cm with volt meter, and 8228 micro S/cm, and 4100 PPM all at 21.7 Celsius. My target EC is much higher at 1.9 mS/cm, but I do not trust these numbers.
As you are helping me think about this, I never had a problem until I allowed some plants to over grow. The theory that the massive plants are sucking up all the nutrients does not seem to explain why some plants managed to start from a seedling and grow healthy. However, now that I think aobut it, it is less than 10% (maybe 2 %) of seedlings that grow healthy now, so maybe they are some kind fluke?
When I try to start younger plants, even the same kind of plant next to an established plant, the larger plant will not tolerate it and the younger plant fails to thrive every time. Since, you have used this formula well for years, I don't think it is the solution, but I still think it may be because the plants are of vastly different ages. Are the larger plants blocking the light or maybe you have some pests in the system and they are attacking the weakest plants first? Have you grown plants that are mature next to seedlings successfully before? When I worked on the farm, we always planted every biofilter or rail at the same time. Old plants were not left in. We also did not grow plants that were harvested longer than 50 days on a rail system. Longer lived plants and plants we get multiple harvests from were in biofilters and even those beds were always cleaned and planted all at once unless we used the 100 ft beds and we had gaps between different crops like kale and leeks so they would not interfere with each other. Plants don't like competition around their root zones, so we would have to leave a gap if we were going to plant seedlings next to an established crop. It does not explain why some plants downstream of the kale were fine.
Imafan, Thanks for the help! Great questions which I answer below. My key question is Should I be monitoring and adding additional nutrients occasionally?
I don’t think I have successfully grown new plants next to very old ones. It is not just proximity to old plants, however. It is hard to start new plants in rows with no very old plants also. A few work, but less than 10%. I doubled the nutrients and I noticed one plant that has leaves that are half green (see photo) which I did not notice when I started this thread.
As for nutrients, I mix nutrients into solution to my target concentration and only add water with nutrients - no plain water. It has been my understanding that, using this practice, I do not need to monitor nutrient concentration or ever add additional nutrients. But that assumes that all plants use nutrients at the same rate regardless of age. Should I be monitoring and adding additional nutrients occasionally? Maybe I should just subtract the baseline ppm or conductivity from the extra sediment?
Pests is a good question. My system in indoors and there are no visible bugs or animals. I do have green algae growing on the top surface of my grow cubes. The roots look the same to me until the plant is almost dead.
When this problem started, I drained the system, flushed it, and then refilled with new water. It did not remove all the old sediment, and any pathogens, would have been greatly reduced, but would still be there. There were a few times I filled with water that had lots of sediment in it, thinking that extra nutrients can’t hurt since I’m not monitoring ppm anyway. If the plants were in dirt, they would have loved that water!
I don’t think I have successfully grown new plants next to very old ones. It is not just proximity to old plants, however. It is hard to start new plants in rows with no very old plants also. A few work, but less than 10%. I doubled the nutrients and I noticed one plant that has leaves that are half green (see photo) which I did not notice when I started this thread.
As for nutrients, I mix nutrients into solution to my target concentration and only add water with nutrients - no plain water. It has been my understanding that, using this practice, I do not need to monitor nutrient concentration or ever add additional nutrients. But that assumes that all plants use nutrients at the same rate regardless of age. Should I be monitoring and adding additional nutrients occasionally? Maybe I should just subtract the baseline ppm or conductivity from the extra sediment?
Pests is a good question. My system in indoors and there are no visible bugs or animals. I do have green algae growing on the top surface of my grow cubes. The roots look the same to me until the plant is almost dead.
When this problem started, I drained the system, flushed it, and then refilled with new water. It did not remove all the old sediment, and any pathogens, would have been greatly reduced, but would still be there. There were a few times I filled with water that had lots of sediment in it, thinking that extra nutrients can’t hurt since I’m not monitoring ppm anyway. If the plants were in dirt, they would have loved that water!
Nutrient requirements for plants vary at different stages of growth. That is why for long term fruiting crops like tomatoes in hydroponic systems, often a different formula is used for the growth and fruiting stages.
It is unlikely that plants would use nutrients at the same rate. Different plants for sure would have different nutrient requirements. Larger plants usually not only suck up more water because of their larger root systems, they also take up the lion share of nutrients.
There is also the problem of alleopathy when you have plants of different ages. Larger plants will often release chemicals that inhibit growth of other plants that may compete with them. A lot of the alleopathy can be altered by the type of plant as some plants are more alleopathic than others and the ratio of the different kinds of plants or plants in different growth stages.
I am not familiar with just topping off solutions. Usually, if crops are kept more than 50 days, or in the case of tomatoes when the growth stage changes, the reservoir is drained (the solution is fine for use in the garden), and new solution is made. This was for a Kratky system.
When I worked on the farm, the hydroponic system was controlled with a controller and all they had to do was make sure the stock tanks were filled regularly. The controller made all the adjustments within the parameters that were set. All of the rails were harvested at once in sections. Old and new plantings were not mixed on the same rail.
It is unlikely that plants would use nutrients at the same rate. Different plants for sure would have different nutrient requirements. Larger plants usually not only suck up more water because of their larger root systems, they also take up the lion share of nutrients.
There is also the problem of alleopathy when you have plants of different ages. Larger plants will often release chemicals that inhibit growth of other plants that may compete with them. A lot of the alleopathy can be altered by the type of plant as some plants are more alleopathic than others and the ratio of the different kinds of plants or plants in different growth stages.
I am not familiar with just topping off solutions. Usually, if crops are kept more than 50 days, or in the case of tomatoes when the growth stage changes, the reservoir is drained (the solution is fine for use in the garden), and new solution is made. This was for a Kratky system.
When I worked on the farm, the hydroponic system was controlled with a controller and all they had to do was make sure the stock tanks were filled regularly. The controller made all the adjustments within the parameters that were set. All of the rails were harvested at once in sections. Old and new plantings were not mixed on the same rail.
Yes, the controller tests and adjusts the solution with every pass. Depending on the crop different amounts of nutrients are taken out.
For instance lettuce and corn use a lot of nitrogen and phosphorus, cucumbers use a lot of micros like potassium, magnesium, zinc, and calcium, kale uses a lot of calcium. The controller monitors pH, EC, and other parameters and adjusts automatically. This is what allows the farm to be able to grow a variety of different crops within a hoop house. Not all crops are suited for a rail system, usually the crops are short lived about 6 weeks. Even though some of the crops could grow longer, they usually do not do more than 3 harvests from them ex kale. It is also easier to use this system if all the plants are harvested. Older plants become a liability over time and their root systems can become so large that they start to restrict flow.
For instance lettuce and corn use a lot of nitrogen and phosphorus, cucumbers use a lot of micros like potassium, magnesium, zinc, and calcium, kale uses a lot of calcium. The controller monitors pH, EC, and other parameters and adjusts automatically. This is what allows the farm to be able to grow a variety of different crops within a hoop house. Not all crops are suited for a rail system, usually the crops are short lived about 6 weeks. Even though some of the crops could grow longer, they usually do not do more than 3 harvests from them ex kale. It is also easier to use this system if all the plants are harvested. Older plants become a liability over time and their root systems can become so large that they start to restrict flow.