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#1
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cattleya leaf tip necrosis
I have a Cattleya that I bought as a bare root plantlet almost 5 years
ago. It has taken a long time to get going, but is now growing well and sending its first flower shoot. It was probably too dry and underfed in previous years, because it (along with my phals) has responded very well to finer bark medium and a heavier feeding regime. I'm now using 200 ppm N in a weekly soak with made with a 20-20-20 + trace elements fertiliser. One of the Cattleya's leaves is black at the tip and it's progressing. There is now maybe 15 mm of dry black leaf at the tip and then a band of chlorosis of 3 or 4 mm wide. Can anyone offer an educated gues on whether this is due to salinity, lack of Ca, a virus, or something else? The fertiliser I'm using doesn't contain Ca, but the water is very hard, containing an average of 276 ppm of total hardness as CaCO3 according to the water company. Leo |
#2
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cattleya leaf tip necrosis
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#3
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cattleya leaf tip necrosis
The calcium found in water is almost totally unabsorbable by plants(or
humans for that matter). Makes my blood boil every time i see a tums commercial telling people that it "contains calcium that your body needs". Calcium nitrate is very readily absorbed and is very cheap. |
#4
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cattleya leaf tip necrosis
Duncan Vincent wrote: The calcium found in water is almost totally unabsorbable by plants(or humans for that matter). Makes my blood boil every time i see a tums commercial telling people that it "contains calcium that your body needs". Calcium nitrate is very readily absorbed and is very cheap. Really?? I'm surprised that you would say that. I can't say much about plants and what they can absorb, in the way of calcium. On the other hand, Tums is calcium carbonate I believe. The calcium supplement that my physician wants me to take and the same one my wife's doctor wants her to take uses calcium carbonate as the calcium source. I'm aware of the vitamin D connection and humans absorbing and using calcium and I'm aware that calcium citrate is an alternative as a calcium supplement. As I understand it, calcium citrate can be absorbed when taken without food but calcium carbonate should be taken with food because stomach acid is required to make it absorbable. I suppose people taking strong acid suppressors would need to keep this in mind. Sorry to emphasize the off topic half of your comments but if you are going to convince me that Tums are not useful as a calcium supplement, I'll need more information before I believe it. (Feel free to prove me wrong. I like to learn.) Steve |
#5
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cattleya leaf tip necrosis
I agree with Steve.
Whether the source of the calcium is a carbonate or nitrate, in solution the calcium is in the form of the ion Ca++, and that is absorbable by all. -- Ray Barkalow - First Rays Orchids - www.firstrays.com Plants, Supplies. Books, Artwork, and lots of Free Info! "Steve" wrote in message ... Duncan Vincent wrote: The calcium found in water is almost totally unabsorbable by plants(or humans for that matter). Makes my blood boil every time i see a tums commercial telling people that it "contains calcium that your body needs". Calcium nitrate is very readily absorbed and is very cheap. Really?? I'm surprised that you would say that. I can't say much about plants and what they can absorb, in the way of calcium. On the other hand, Tums is calcium carbonate I believe. The calcium supplement that my physician wants me to take and the same one my wife's doctor wants her to take uses calcium carbonate as the calcium source. I'm aware of the vitamin D connection and humans absorbing and using calcium and I'm aware that calcium citrate is an alternative as a calcium supplement. As I understand it, calcium citrate can be absorbed when taken without food but calcium carbonate should be taken with food because stomach acid is required to make it absorbable. I suppose people taking strong acid suppressors would need to keep this in mind. Sorry to emphasize the off topic half of your comments but if you are going to convince me that Tums are not useful as a calcium supplement, I'll need more information before I believe it. (Feel free to prove me wrong. I like to learn.) Steve |
#6
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cattleya leaf tip necrosis
hmmm my reply dissappeared. wasnt a very good one anyway. CaCo3 doesnt
dissolve very well were as nitrate does. I believe that the calcium in water is actually calcium bi-carbonate and it can only exist in soloution. My high school chem is a bit fuzzy but the ion logic sounds about right however dissolved and disasociated arent the same thing. I grow Hydro and i cant say absoulutly that calcium bi carbonate will not supply plants with the amount of Ca they need. Our water here in Calgary is quite high in Ca( 130-250 ppm CaCO3 according to the water treatment plant) but i will get Ca deficency if I dont add nitrate. According to Wikipedia CaCO3 reacts with your stomach acid and turns into CaCl, which is soluble. "Ray B" wrote in message ... I agree with Steve. Whether the source of the calcium is a carbonate or nitrate, in solution the calcium is in the form of the ion Ca++, and that is absorbable by all. -- Ray Barkalow - First Rays Orchids - www.firstrays.com Plants, Supplies. Books, Artwork, and lots of Free Info! "Steve" wrote in message ... Duncan Vincent wrote: The calcium found in water is almost totally unabsorbable by plants(or humans for that matter). Makes my blood boil every time i see a tums commercial telling people that it "contains calcium that your body needs". Calcium nitrate is very readily absorbed and is very cheap. Really?? I'm surprised that you would say that. I can't say much about plants and what they can absorb, in the way of calcium. On the other hand, Tums is calcium carbonate I believe. The calcium supplement that my physician wants me to take and the same one my wife's doctor wants her to take uses calcium carbonate as the calcium source. I'm aware of the vitamin D connection and humans absorbing and using calcium and I'm aware that calcium citrate is an alternative as a calcium supplement. As I understand it, calcium citrate can be absorbed when taken without food but calcium carbonate should be taken with food because stomach acid is required to make it absorbable. I suppose people taking strong acid suppressors would need to keep this in mind. Sorry to emphasize the off topic half of your comments but if you are going to convince me that Tums are not useful as a calcium supplement, I'll need more information before I believe it. (Feel free to prove me wrong. I like to learn.) Steve |
#7
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cattleya leaf tip necrosis
Duncan,
Once a compounds dissolve, they do dissociate, so I am uncertain of the point of your comment about them. In neutral pH, CaCO3 has a solubility of only about 14 mg/L in water. Calcium bicarbonate is considerably more soluble, but it takes the presence of a lot of free CO2 to form it in solution, and as the air only contains about 0.03-0.04% CO2, you pretty much have to bubble CO2 through the water to form appreciable amounts of the bicarbonate, or give it lots of time to react and reassociate. Calcium nitrate, on the other hand, is about a million times more soluble at about 1200 grams/liter. Given that, the ion in solution - depending upon the pH and other dissolved species, of course - will be the same, and is equally absorbable by plants. Be careful how you read that water report. Instead of showing dissolved ions individually, many municipal water systems report "alkalinity" in terms of calcium carbonate content. In reality, it is the measure of the amount of acid it takes to lower the pH a certain amount - a measure of the acid-buffering capacity - and it is not a specific ion, but is made up of carbonate and bicarbonates of a variety of cations, usually calcium, magnesium and sodium. Based upon the solubility alone (14 ppm), it is unlikely there is 130-250 ppm CaCO3 in your water supply, which would provide about 50-100 ppm Ca - it's probably a lot lower than that, and if you consider that in a 125 ppm N fertilizer solution (MSU RO formula), there is about 75 ppm Ca, it's no wonder that in the water is insufficient. There is some recent evidence that shows a plants' usage of Ca is determined in part by the Mg present, as well. -- Ray Barkalow - First Rays Orchids - www.firstrays.com Plants, Supplies. Books, Artwork, and lots of Free Info! "Duncan Vincent" wrote in message ... hmmm my reply dissappeared. wasnt a very good one anyway. CaCo3 doesnt dissolve very well were as nitrate does. I believe that the calcium in water is actually calcium bi-carbonate and it can only exist in soloution. My high school chem is a bit fuzzy but the ion logic sounds about right however dissolved and disasociated arent the same thing. I grow Hydro and i cant say absoulutly that calcium bi carbonate will not supply plants with the amount of Ca they need. Our water here in Calgary is quite high in Ca( 130-250 ppm CaCO3 according to the water treatment plant) but i will get Ca deficency if I dont add nitrate. According to Wikipedia CaCO3 reacts with your stomach acid and turns into CaCl, which is soluble. "Ray B" wrote in message ... I agree with Steve. Whether the source of the calcium is a carbonate or nitrate, in solution the calcium is in the form of the ion Ca++, and that is absorbable by all. -- Ray Barkalow - First Rays Orchids - www.firstrays.com Plants, Supplies. Books, Artwork, and lots of Free Info! "Steve" wrote in message ... Duncan Vincent wrote: The calcium found in water is almost totally unabsorbable by plants(or humans for that matter). Makes my blood boil every time i see a tums commercial telling people that it "contains calcium that your body needs". Calcium nitrate is very readily absorbed and is very cheap. Really?? I'm surprised that you would say that. I can't say much about plants and what they can absorb, in the way of calcium. On the other hand, Tums is calcium carbonate I believe. The calcium supplement that my physician wants me to take and the same one my wife's doctor wants her to take uses calcium carbonate as the calcium source. I'm aware of the vitamin D connection and humans absorbing and using calcium and I'm aware that calcium citrate is an alternative as a calcium supplement. As I understand it, calcium citrate can be absorbed when taken without food but calcium carbonate should be taken with food because stomach acid is required to make it absorbable. I suppose people taking strong acid suppressors would need to keep this in mind. Sorry to emphasize the off topic half of your comments but if you are going to convince me that Tums are not useful as a calcium supplement, I'll need more information before I believe it. (Feel free to prove me wrong. I like to learn.) Steve |
#8
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cattleya leaf tip necrosis
"Ray B" wrote in message ... . . . In reality, it is the measure of the amount of acid it takes to lower the pH a certain amount - a measure of the acid-buffering capacity - and it is not a specific ion, but is made up of carbonate and bicarbonates of a variety of cations, usually calcium, magnesium and sodium. Best not use words I do not know, so I am staying away from cations. But I think potassium could also be added to the list. Potassium bicarbonate is commonly added to water to add alkalinity. J. R. Peters used to sell straight potassium bicarbonate for use with their R.O. fertilizer formulation. It has been replaced with a mix of calcium, magnesium, and potassium bicarbonates. Pat |
#9
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cattleya leaf tip necrosis
On Nov 9, 6:09*am, "Ray B" wrote:
Duncan, Once a compounds dissolve, they do dissociate, so I am uncertain of the point of your comment about them. Umm, that's not quite true is it? For example, sugar (e.g. sucrose) dissolves but doesn't dissociate. Sucrose will hydrolize but that's a separate reaction from dissolution and requires a catalyst/enzyme or heating for any significant hydrolysis to take place. Although in the vast majority of cases compounds do dissociate when they dissolve the point is that it is not true that dissolution = dissociation. While not very relevant to the discussion his point is valid. Dave |
#10
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cattleya leaf tip necrosis
It depends upon whether it is an ionically-bonded compound or not, doesn't
it? -- Ray Barkalow - First Rays Orchids - www.firstrays.com Plants, Supplies. Books, Artwork, and lots of Free Info! "dbs" wrote in message ... On Nov 9, 6:09 am, "Ray B" wrote: Duncan, Once a compounds dissolve, they do dissociate, so I am uncertain of the point of your comment about them. Umm, that's not quite true is it? For example, sugar (e.g. sucrose) dissolves but doesn't dissociate. Sucrose will hydrolize but that's a separate reaction from dissolution and requires a catalyst/enzyme or heating for any significant hydrolysis to take place. Although in the vast majority of cases compounds do dissociate when they dissolve the point is that it is not true that dissolution = dissociation. While not very relevant to the discussion his point is valid. Dave |
#11
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cattleya leaf tip necrosis
On Nov 12, 4:54*pm, "Ray B" wrote:
It depends upon whether it is an ionically-bonded compound or not, doesn't it? That's the general rule that we were taught in General Chemistry ISTR. But, if memory serves, covalently bonded chemicals tend to be insoluble unless they have an uneven charge distribution spatially. Alcohols are an interesting group that dissolves but doesn't dissociate due to the hydroxyl group that introduces a spatial charge disparity. My previous example of sucrose is an interesting exception to that rule because they will dissociate upon heating. Brewers use the fact that sucrose hydrolyzes to produce an invert sugar that has better fermentation properties (though an acid is usually employed as a catalyst). Cooks also "invert" sucrose by an addition of corn syrup (aka fructose) while heating a sucrose solution to prevent crystalization during cooling. Dave -- Ray Barkalow - First Rays Orchids -www.firstrays.com Plants, Supplies. Books, Artwork, and lots of Free Info! "dbs" wrote in message ... On Nov 9, 6:09 am, "Ray B" wrote: Duncan, Once a compounds dissolve, they do dissociate, so I am uncertain of the point of your comment about them. Umm, that's not quite true is it? For example, sugar (e.g. sucrose) dissolves but doesn't dissociate. Sucrose will hydrolize but that's a separate reaction from dissolution and requires a catalyst/enzyme or heating for any significant hydrolysis to take place. Although in the vast majority of cases compounds do dissociate when they dissolve the point is that it is not true that dissolution = dissociation. While not very relevant to the discussion his point is valid. Dave |
#12
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cattleya leaf tip necrosis
dbs wrote: .......... Cooks also "invert" sucrose by an addition of corn syrup (aka fructose) while heating a sucrose solution to prevent crystalization during cooling. Dave ......................... In an effort to take this subject even farther off topic (If that's even possible now): Actually, corn syrup is glucose. We hear so much about the man made/manipulated high fructose corn syrup these days that I can understand the mistake. Probably the only reason we see so much high fructose corn syrup around is because it is as sweet as sucrose and cheaper due to our own government. They place a tariff on imported sucrose and subsidize farmers who grow corn. Steve |
#13
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cattleya leaf tip necrosis
It probably wouldn't hurt to soak the plant in a dilute solution
of calcium nitrate or calcium chloride. That would help draw out any accumulated salts, and impart some known concentration of calcium. Several years ago, I had some ICP tests done on orchid media recovered from flasks with cattleyas suffering leaf-tip necrosis that was characteristic of calcium deficiency. I don't have the values handy just right now, but I recall the calcium levels were in the high-double digit or very low triple digit parts per million level, and the cattleys were showing the "terminal" signs of calcium deficiency. The address in the header is bogus. Send no email there. -AJHicks Chandler, AZ |
#14
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cattleya leaf tip necrosis
On Nov 17, 6:36*am, (Aaron Hicks) wrote:
* * * * It probably wouldn't hurt to soak the plant in a dilute solution of calcium nitrate or calcium chloride. That would help draw out any accumulated salts, and impart some known concentration of calcium. * * * * Several years ago, I had some ICP tests done on orchid media recovered from flasks with cattleyas suffering leaf-tip necrosis that was characteristic of calcium deficiency. I don't have the values handy just right now, but I recall the calcium levels were in the high-double digit or very low triple digit parts per million level, and the cattleys were showing the "terminal" signs of calcium deficiency. Thanks for this suggestion and also to Ray. Since the bedrock here is calcium carbonate ('Southern England Chalk Formation'), I have little doubt that the water hardness is mostly due to Ca++. The fact that it is expressed as CaCO3 in the report I cited is just an analytical convenience. I imagine there's plenty of acid in the rain here to mobilise the Ca++. As Ray pointed out, if the hardness all Ca++, this would put me in the range of MSU RO formula. You observation indicates that under some conditions this might not be sufficient. Does anybody know of a source of MSU formula fertiliser in England (or is the recipe available?) Leo |
#15
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cattleya leaf tip necrosis
No fertilizer manufacturer is likely to share their formula, but by law they
are required to list the contents and percentages in the final formula, so if you can figure out the makeup of the ingredients, it's fairly simple - although time consuming - to reverse engineer it. http://www.firstrays.com/MSUFert_RO.htm http://www.firstrays.com/MSUFert_Well.htm -- Ray Barkalow - First Rays Orchids - www.firstrays.com Plants, Supplies. Books, Artwork, and lots of Free Info! wrote in message ... On Nov 17, 6:36 am, (Aaron Hicks) wrote: It probably wouldn't hurt to soak the plant in a dilute solution of calcium nitrate or calcium chloride. That would help draw out any accumulated salts, and impart some known concentration of calcium. Several years ago, I had some ICP tests done on orchid media recovered from flasks with cattleyas suffering leaf-tip necrosis that was characteristic of calcium deficiency. I don't have the values handy just right now, but I recall the calcium levels were in the high-double digit or very low triple digit parts per million level, and the cattleys were showing the "terminal" signs of calcium deficiency. Thanks for this suggestion and also to Ray. Since the bedrock here is calcium carbonate ('Southern England Chalk Formation'), I have little doubt that the water hardness is mostly due to Ca++. The fact that it is expressed as CaCO3 in the report I cited is just an analytical convenience. I imagine there's plenty of acid in the rain here to mobilise the Ca++. As Ray pointed out, if the hardness all Ca++, this would put me in the range of MSU RO formula. You observation indicates that under some conditions this might not be sufficient. Does anybody know of a source of MSU formula fertiliser in England (or is the recipe available?) Leo |
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