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Micronutrients, truth, advice and reality
A few addressed questions, gathered here and there in the thread :
- What is wrong with MSU, 15-5-15 CalMag and similar fertilizers ( very high high NO3/NH3 ratio, if not exclusive) ? Everyone will tell you those are great, fantastic and so on. Foliar analysis reveal certain trends with their use. Some micronutrients decrease, some others increase, and so on. Eventually, after those micronutrients will be exhausted, the plants will die, no matter what can be done when the symptoms start to be severe. Jerry Fisher, from Orchids Limited : http://www.orchidweb.com/dtl_spk.asp?PRecno=988 He provides advice to partially prevent the problem, by using a lower NO3/NH4 ratio ( thus lowering the pH, supplying NH4, and temporarily preventing the need for a quite dangerous and necessary micronutrient supplementation). Many other problems can, and will arise because of those "new" fertilizers, or substrates. It takes a lot of time to visually assess the problem, but usually when such problems can be visually addresse, the grower is more or less broke. micronutrient deficiencies and toxicities, once they have been going on too far, are hard, if not impossible to correct. Growers have been using high urea fertilizers with limes for ages, with no troubles at all. Now, urea is evil, ammonia is too, and nitrate is the way to go. It might be partially possible to use plain NO3 fertilizers, but not without foliar analysis, substrate analysis, pH correction of both the substrate and the irrigation water, and micronutrients supplementation. NO3 prevents many bacterial diseases, that can be addressed easily when using urea, or ammonium fertilizers : test fertilizer solution and substrate, both pH and EC. Testing fertilizer alone is not enouh. Preventing loss of the entire collection by fertilizer misuse : US$30 foliar analysis from time to time. Free in certain states or countries. Monitor from time to time. Comparisons helps to see problems BEFORE the will arise. 99% of the orchids that die of a non-obvious conditions have been affected by such deficiencies or toxicities. "Phragmipedium besseae made easy... " Besseae and its hybrids have been one of the most proeminent victims from this lack of interest in foliar analysis... Happy plant, then one specific micronutrient increase up to a certain level, another one drops. Watery marks appear on the lower side of the leaves. Plants stops growing, stops rooting, make multiple tiny shoots, wilt and die. Bye bye. Lowering the pH is far from enough, to relably grow those plants... - CHC has been known to be extremely dificult, dangerous to use. Everyone knew that in the professionnal pot-plant trade, especially the special calcium nitrate process ( and no, heavy watering can not replace the initial calcium nitrate soak). It took 7 years amongst smaller growers to be discovered as essential. Cost : US$40 destructive analysis. CHC must be analyzed every other month, to monitor the changes, especially micronutrient (over)load. Before getting any advice on fertilizers and substrate, the sole question to ask is "have you done foliar and substrate analysis on the long term ?" Others comments are unfortunately worthless and the source of many myths or short term "magic bullets". |
#2
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Micronutrients, truth, advice and reality
1). These plants are or could be weeds somewhere. They are just not that
hard as house plants and beginners should not be scared off by theses posts. In the beginning finding the spot with the right light and learning not to overwater will be the biggest problem. Fertilize one or twice a month and water heavily with clear water the rest of the time. The water you drink will be fine, if you let the water sit overnight before use, that is even better. Get a couple of different brands of fertilizer and rotate their use. The difference between a "good" and a "bad" grower may be location. I know of someone who grew wonderful plants using a Poland fertilizer. He was using RO water. He moved to another location, and was still using RO water and the same fertilizer. After a while, the plants looked pretty ugly. RO and DI systems remove more than 95% of calcium, but many studies show that less than 50 % of boron as borate is removed. There is a simple table to understand the problem here : http://www.watertiger.net/RO/countertop.htm and a few others references. When he started to add boron to his fertilizer program, the problems disappeared... In some other states, there may be a boron excess, obviously an high load would not be removed by RO or DI. It is safer for hobbyists to use a mix of tap and rain/RO/DI water anyway. 2). Foliar analysis is not a "magic bullet", just a useful tool. Optimal levels for various orchids are not published. If they are not done regularly, trends will be missed. Testing identifies the symptoms of a problem, not the problem. Finding the problem often requires the help of an expert. Example from here; tests showed tissue very low on P. Started using a fertilizer with a higher P ratio, problem got worst. After talking to the lab people, used a fertilizer with no P for a couple of rotations and the problem started clearing up. (Problem was the pH of the mix was preventing the plants uptake of P and the fertilizer with the higher P ratio just made the pH problem worst). There may be another problem with high P fertilizers. inc is never supplied in large enough quantities and is easily bound as insoluble zinc phosphate. Many orchids have a Zn normal foliar content between 80 and 200 ppm, very high compared to other crops. Zn can induce deficiency somptoms in older leaves, and a chlorosis of the new growth. Another thing about foliar analysis is that it only gives you a very small window of what is going on unless you are will to spend big dollars and cut a lot of leaves. When I send samples, I will make a couple of samples for a greenhouse. A single sample is composed of 1 oz of plant tissue. I make a sample from 6 -12 good looking plants and a sample from 6 -12 bad looking plants. A sample result represent an average of the 6 -12 plants and the highs and lows of the individual plants are lost. I have found the individual plant readings are all over the scale although everything in the greenhouse is getting the same treatment. Orchid scales depends on the genus, but usually some elements are much higher than many other crops. Leaf tip or base, age, all play a role to understand those analysis. Zinc deficiency is easier to assess using the lower part of the leaves, iron toxicity the tips of older leaves. 3). I know 4 or 5 growers who have cooked plants with MSU/Jack's/15-5-15 CalMag after using them almost exclusively for a year or so. Jack's is now recommending a buffer (requiring a second injector) when using theirs. Use these fertilizers with care and rotate with other types of fertilizers. Watch the pH of what is coming out of the pot. Helpful 1 suggests checking what is coming out of the pot every month or so. With my water, potting mix, and fertilizer selections I find I must test more often. (Tied to the pH meter thread of a few weeks ago, I find a $50 pH meter works fine for this purpose. I know the pH of my clear water and when the meter is off by more than 20% I know it is time to calibrate.) Regarding those 15-5-15 CalMag and similar fertilizers. There are several patents numbers appended to the notice. http://www.scottsprohort.com/_docume...xcel/H4045.pdf The patents mention how they can keep calcium and phosphorus together. Urea phosphate complex. When the fertilizer becomes wet, urea can be broken down. The oily liquid found in the improperly stored bags is plain phosphoric acid, with the according pH. Calcium disappears, zinc disappears, and sometimes even iron disappears. If a solution is cloudy, the fertilizer is unusable. Fertilizer solution analysis for professionnal growers is required, to ensure the fertilizer is still usable. I have seen some growers who add 15-5-15 CalMag to their water tank, correct the pH immediately, and use it. They corrected only a part of the acidity, and were burning their plants nicely. 15-5-15 CalMag and all other fertilizers must be dissolved as a stock solution, and only once they are fully dissolved, added to the water tank, and pH-corrected. 4). In both of Helpful 1's posts calcium nitrate is mentioned. This is the third time I have seen it mentioned this year. The lab suggested I might want to consider using a calcium nitrate solution in the first watering of a flush. The other time I saw it (bags and bags of it) was at the greenhouse of someone who was on the other side of major 15-5-15 CalMag damage. It is something I know nothing about. Does anyone know what's up? Calcium nitrate will stabilize the pH and calcium content of your mix, especially if you do not use lime. 15-5-15 CalMag sometimes leaves the plants with a major nitrate deficiency, owing to a specially complex process. Do not forget that those fertilizers have been designed as "plug" fertilizers, to dwarf the plants and ensure maximum flowering on a small plant. Deficiency of a peculiar nutrient can be related to another nutrient. Iron deficiency can be due to a long-term phosphorus deficiency, as an example. |
#3
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Micronutrients, truth, advice and reality
I am sorry, "Helpful 1," but your use of the efficacy of RO units based upon the "Water Tiger"
website is flawed, or at best, over-simplified. (Forgive me, but I've joined Bert Pressman in his quest to quash the dissemination of flawed or outright incorrect orchid growing information.) Granted, input water quality will effect the output quality of RO water to some degree, but not sufficiently to be the difference between "good" plants and "pretty ugly" ones, as the vast majority of water supplies do not carry sufficient nutrients to adequately support decent plant growth anyway, mandating that they be added via fertilizers. There is also an inconsistency in your commentary: If, as you state, "many studies show that less than 50 % of boron as borate is removed" by RO units, then why did the addition of more boron correct the deficiency in the quality of the plants grown by a grower you know? I guess that you could be implying that in his old location there was sufficient "boron breakthrough" that he did not need to supplement, but doesn't that fly in the face of how an RO unit works? My understanding (I could be wrong, and would be happy to receive a correction) is that the membranes function by means of a specific pore size, meaning that only ions less than a certain size will pass. Ions are ions - each is pretty much the same size in any water source. Using hypothetical numbers here, if I had two water supplies, one with 500 ppm TDS and one with 100 ppm TDS, and ran them through a good RO unit, I would expect to see my output water with less than 10 ppm TDS, no matter what. If the first had five times the amount of boron as the second, I would still expect to see approximately the same levels in the output. -- Ray Barkalow - First Rays Orchids - www.firstrays.com Plants, Supplies, Books, Artwork, and Lots of Free Info! .. . . . . . . . . . . "Helpful 1" wrote in message om... 1). These plants are or could be weeds somewhere. They are just not that hard as house plants and beginners should not be scared off by theses posts. In the beginning finding the spot with the right light and learning not to overwater will be the biggest problem. Fertilize one or twice a month and water heavily with clear water the rest of the time. The water you drink will be fine, if you let the water sit overnight before use, that is even better. Get a couple of different brands of fertilizer and rotate their use. The difference between a "good" and a "bad" grower may be location. I know of someone who grew wonderful plants using a Poland fertilizer. He was using RO water. He moved to another location, and was still using RO water and the same fertilizer. After a while, the plants looked pretty ugly. RO and DI systems remove more than 95% of calcium, but many studies show that less than 50 % of boron as borate is removed. There is a simple table to understand the problem here : http://www.watertiger.net/RO/countertop.htm and a few others references. When he started to add boron to his fertilizer program, the problems disappeared... In some other states, there may be a boron excess, obviously an high load would not be removed by RO or DI. It is safer for hobbyists to use a mix of tap and rain/RO/DI water anyway. 2). Foliar analysis is not a "magic bullet", just a useful tool. Optimal levels for various orchids are not published. If they are not done regularly, trends will be missed. Testing identifies the symptoms of a problem, not the problem. Finding the problem often requires the help of an expert. Example from here; tests showed tissue very low on P. Started using a fertilizer with a higher P ratio, problem got worst. After talking to the lab people, used a fertilizer with no P for a couple of rotations and the problem started clearing up. (Problem was the pH of the mix was preventing the plants uptake of P and the fertilizer with the higher P ratio just made the pH problem worst). There may be another problem with high P fertilizers. inc is never supplied in large enough quantities and is easily bound as insoluble zinc phosphate. Many orchids have a Zn normal foliar content between 80 and 200 ppm, very high compared to other crops. Zn can induce deficiency somptoms in older leaves, and a chlorosis of the new growth. Another thing about foliar analysis is that it only gives you a very small window of what is going on unless you are will to spend big dollars and cut a lot of leaves. When I send samples, I will make a couple of samples for a greenhouse. A single sample is composed of 1 oz of plant tissue. I make a sample from 6 -12 good looking plants and a sample from 6 -12 bad looking plants. A sample result represent an average of the 6 -12 plants and the highs and lows of the individual plants are lost. I have found the individual plant readings are all over the scale although everything in the greenhouse is getting the same treatment. Orchid scales depends on the genus, but usually some elements are much higher than many other crops. Leaf tip or base, age, all play a role to understand those analysis. Zinc deficiency is easier to assess using the lower part of the leaves, iron toxicity the tips of older leaves. 3). I know 4 or 5 growers who have cooked plants with MSU/Jack's/15-5-15 CalMag after using them almost exclusively for a year or so. Jack's is now recommending a buffer (requiring a second injector) when using theirs. Use these fertilizers with care and rotate with other types of fertilizers. Watch the pH of what is coming out of the pot. Helpful 1 suggests checking what is coming out of the pot every month or so. With my water, potting mix, and fertilizer selections I find I must test more often. (Tied to the pH meter thread of a few weeks ago, I find a $50 pH meter works fine for this purpose. I know the pH of my clear water and when the meter is off by more than 20% I know it is time to calibrate.) Regarding those 15-5-15 CalMag and similar fertilizers. There are several patents numbers appended to the notice. http://www.scottsprohort.com/_docume...xcel/H4045.pdf The patents mention how they can keep calcium and phosphorus together. Urea phosphate complex. When the fertilizer becomes wet, urea can be broken down. The oily liquid found in the improperly stored bags is plain phosphoric acid, with the according pH. Calcium disappears, zinc disappears, and sometimes even iron disappears. If a solution is cloudy, the fertilizer is unusable. Fertilizer solution analysis for professionnal growers is required, to ensure the fertilizer is still usable. I have seen some growers who add 15-5-15 CalMag to their water tank, correct the pH immediately, and use it. They corrected only a part of the acidity, and were burning their plants nicely. 15-5-15 CalMag and all other fertilizers must be dissolved as a stock solution, and only once they are fully dissolved, added to the water tank, and pH-corrected. 4). In both of Helpful 1's posts calcium nitrate is mentioned. This is the third time I have seen it mentioned this year. The lab suggested I might want to consider using a calcium nitrate solution in the first watering of a flush. The other time I saw it (bags and bags of it) was at the greenhouse of someone who was on the other side of major 15-5-15 CalMag damage. It is something I know nothing about. Does anyone know what's up? Calcium nitrate will stabilize the pH and calcium content of your mix, especially if you do not use lime. 15-5-15 CalMag sometimes leaves the plants with a major nitrate deficiency, owing to a specially complex process. Do not forget that those fertilizers have been designed as "plug" fertilizers, to dwarf the plants and ensure maximum flowering on a small plant. Deficiency of a peculiar nutrient can be related to another nutrient. Iron deficiency can be due to a long-term phosphorus deficiency, as an example. |
#4
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Micronutrients, truth, advice and reality
Ray wrote:
My understanding (I could be wrong, and would be happy to receive a correction) is that the membranes function by means of a specific pore size, meaning that only ions less than a certain size will pass. Ions are ions - each is pretty much the same size in any water source. Using hypothetical numbers here, if I had two water supplies, one with 500 ppm TDS and one with 100 ppm TDS, and ran them through a good RO unit, I would expect to see my output water with less than 10 ppm TDS, no matter what. If the first had five times the amount of boron as the second, I would still expect to see approximately the same levels in the output. John Talpa is probably lurking somewhere, waiting to pounce... But in my opinion the only difference would be the amount of waste water generated. You will get more rejected water from the initial solution of 500TDS than 100TDS. But if the membrane is in good condition, the output water should be very close in final composition. Personally, I could see a problem if a grower used 'pure' RO water and a commercial fertilizer designed for soil grown plants. But does anybody who goes to the trouble of getting an RO unit do that? I use a complete hydroponic fertilizer for the very reason that I know I'm removing trace elements from my water. My fertilizer has boron and molybdenum and nickel, and deity only knows what else in it. Rob -- Rob's Rules: http://www.msu.edu/~halgren 1) There is always room for one more orchid 2) There is always room for two more orchids 2a. See rule 1 3) When one has insufficient credit to purchase more orchids, obtain more credit |
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