Author Topic: Coconut deficiency and treatment  (Read 3247 times)

KarenRei

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Coconut deficiency and treatment
« on: March 18, 2018, 08:47:26 PM »
As discussed here, somewhat offtopic:

http://tropicalfruitforum.com/index.php?topic=27233.0

... I've long been rather lax about my fertilizer routine, and am working to amend my wicked ways  ;)  In regards to this, I'm working to treat a deficiency in my Fiji Dwarf coconut.  Symptoms:

 * Deficiency in a mobile nutrient (N P K Mg Cl Mo Ni), as the symptoms are in the oldest leaves, while new leaves are just fine
 * The main symptom is chlorosis, eventually progressing to necrosis.  Chlorisis begins further down the leaflets, yellowing (pure yellow, not spotty/blotchy), affecting the central vein and the edges last.
 * This, I understand, to be a symptom of K deficiency, which I also understand to be the most common deficiency in palms

Leaf that is mostly yellowed, but necrosis is just beginning at the tip:


Zoomed in to the necrotic portions:


Leaf with nearly-full necrosis next to it:


Section of a leaf going chlorotic:


Comparison between the basal portions of the necrotic vs. the yellow leaf:


Older images of an old frond (ignore the cutoff leaflets on the right):



Progression of yellowing up the same old frond, 2 1/2 weeks later (sorry for the red lighting):



Attempts at treatment thusfar:

 * Started out rather half-arsed  ;)
 * First looked up *proper* fertilization for coconut palms, which for a palm the size of mine should be about 200 grams of my fertilizer I had been using** per month, plus extra potassium. I had probably been averaging about 50 grams, with no extra potassium - but it's hard to say because I hadn't been measuring.  The fertilizer is 12-14-14.
 * I started out just giving a proper single monthly dose at the start of the month, but that did nothing to reverse what's clearly been a problem that's built up over time.
 * Over time I made minor, trivial additions of more potassium, magnesium, and trace elements, as well as starting foliar feeding (but AFAIK that was kind of hopeless for macronutrients like potassium)
 * Eventually (~5 days ago?) I looked up how to treat a potassium deficiency, and found out that the amount of fertilizer I should be adding to remedy is huge, something like 1 to 1,5kg, and that it should be a 3:1 ratio of potassium sulfate to magnesium sulfate to avoid inducing magnesium deficiency.  I've so far added about 400g, as I don't want to add it all at once (it's been in two doses so far)
 * Today - although it's doubtful that it's the primary problem - I also added some (maybe ~80g) of sodium chloride (just regular table salt).  Our water isn't chlorinated, so this tree has probably never gotten any added chlorine in its life, and my reading was suggesting that coconut palms are unusual in actually liking chlorine, and that addition of saltwater has been known to help perk them up.  Adding salt to soil goes against every bone in my body, but....

The palm is 3,2m (10' 6") tall to the top of the highest fronds, with the fronds starting to separate at around 80cm up (2' 6"), and a trunk diameter of 10cm (4").  The soil depth is 60cm, and the pot is 80cm wide.  So in gallons, that's probably around 50 gal.  5 fronds - 2 old fronds undergoing chlorosis / necrosis to varying degrees, 2 mature and mostly or completely healthy fronds, and 1 new frond opening up.

The other issue that comes to mind is root health.  Shot suggested soil temperature, pathogens.

Soil temperature should be around 24°C (75°F), day and night, all seasons, at all depths.  Air temperatures vary, and increase with height, but probably average around 30°C (86°F), and humid.  I didn't used to, but I've taken to misting my plants several times a day as well.

I did have an outbreak of fungus gnats starting last month and peaking several weeks ago.  Their numbers have been declining of late as I found a place where I could buy predatory insects (yeay!).  They're still around, but not nearly as common.  Apart from fungus gnats, the only other pest that I ever have had problems with is spider mites (they've killed more plants than I care to admit over the years).  No unusual numbers of them of late, and I bought some predators for them as well just in case.

Aeration: the pots have holes drilled at the bottom, but they're such large pots, and plastic, and the soil is so moist, that obviously root rot is something to consider.  Normally I try to prevent this simply by not watering the large pots too often, but now I'm facing conflicting interests; I have to water to rinse fertilizers into the soil (and the more I water, the deeper they'll wash in)... yet if root rot is of concern then I want to water as *little* as possible.  I have no frond wilting, so that's a good start.  I did - 2-3 weeks ago - drill a lot of side holes.  I might go in at some point and double the number of side holes.  I obviously don't want to go so far that I ruin the pot's structural integrity, or I'll have to coat it in fibreglass to reinforce it - but I could probably do more.  Regardless, the soil is very moist right now.  Question of whether I should be relocating the palm to outside the humidity tent to try to dry it out, or just backing off on waterings (aka, washing in nutrients) for a while.  Again, there's no wilting, so maybe it's not a primary concern right now.

Thoughts, suggestions?
« Last Edit: March 18, 2018, 09:09:27 PM by KarenRei »
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shot

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Re: Coconut deficiency and treatment
« Reply #1 on: March 18, 2018, 10:25:16 PM »
Calcium is very important, competing nutrients.
cocos really like heat, hot and wet is great now cool not so much
pics  were good

I'm getting sleepy, have to call it a night


KarenRei

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Re: Coconut deficiency and treatment
« Reply #3 on: March 19, 2018, 04:44:38 AM »
Calcium is very important, competing nutrients.
cocos really like heat, hot and wet is great now cool not so much
pics  were good

I'm getting sleepy, have to call it a night

Quote from: palmcity
http://www.cropnutrition.com/potassium-sulfate             

http://krishikosh.egranth.ac.in/bitstream/1/5810000191/1/Nakka%20Sathi%20Babu.pdf
Inverse relationship of potassium to boron levels in leafs, but both are needed.

http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.512.9176&rep=rep1&type=pdf

http://www.kno3.org/en/recommendations/foliar-applications-of-potassium-nitrate

https://www.gardeningknowhow.com/edible/fruits/coconut/fertilizing-coconut-palm-trees.htm

 ;)  https://laidbackgardener.blog/tag/coconut-palm-as-a-houseplant/
https://gardens.everybodyshops.com/grow-without-soil-indoors-with-hydroponics/

Thanks for the advice.  :)

There's no signs of calcium or boron deficiency.  But it's probably wise to add some alongside the potassium and magnesium.  I accidentally induced a calcium deficiency in one of my bananas while treating a potassium deficiency, and certainly don't want to do similar to the palm.  And it's not like it's a calciferous soil (it's a mix of perlite, sand, and organic matter... more of the latter than I'd prefer, but I ran out of perlite and didn't want the weight to be too unbearable), so calcium is not unlimited.

Do you feel that the soil or air temperatures listed above (~24°C/75°F for the soil, ~30°C/86°C for the average air temp) are too cool?  Raising temperatures is easy; lowering them not so much  ;)  This comes with caveats, however:

 * If I raise the average temperature, then that raises the peak temperatures from fluctuations as well, and the near-ceiling temperatures (which are higher than average temperatures). 
 * I only have one environment for all of my plants to live in.  I can adjust their individual temperatures to some extent with how high they're positioned on shelves, but this can't be done for large plants (in large pots) or climbers which cross many different heights.

I've lost a number of plants over the years to excess heat, but not a single one due to cold.  So I'm always a bit apprehensive about deliberately elevating the temperature  ;)

Potassium sulfate is indeed the form I'm supplementing with, as A) I saw it specifically recommended for treating deficiencies, B) I don't have potassium chloride on hand, and C) I don't want to be adding excess nitrate while treating a potassium deficiency  :)

Re, "houseplants" - nothing I have is grown as a "houseplant", unless you consider most houseplants to be "plants grown in rain barrels inside humidity tents under a 4-to-5 meter ceiling with lights intense enough that they leave you seeing pink"  ;)  As for the claim that " the great botanical gardens of the northern hemisphere (Kew, Montreal, Berlin, New York, etc.) are not able to cultivate this large palm tree ", yes, they do.  Kew, Berlin, and Eden even have Lodoicea!  (That's actually my dream plant... unfortunately it's just not practical to grow, even in the large greenhouse project being planned here... too massive, too slow, too dioecious). 

Re, the hydroponics article - heh, I'd love to see someone growing a full-sized coconut on hydroponics.  ;)  Shouldn't be impossible, but not a task for me!  ;)  I've done small scale hydroponics before, and I'll just say that the results didn't tempt me to switch over from soil culture (by and large it just adds new potential ways to mess up and kill your plants  ;)  )
« Last Edit: March 19, 2018, 04:49:11 AM by KarenRei »
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palmcity

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Re: Coconut deficiency and treatment
« Reply #4 on: March 19, 2018, 09:27:02 AM »
I am not advocating you try this as I have not tried it as I only grow a few coconut trees around my house and have done little supplementing in my soil near the coconut trees. I may try adding some lower levels of borax/potassium but have not yet and it appears it takes 3-6 months to evaluate the results seen in the plants with changes so I will go slow to my additions of elements.

Hopefully a professional coconut grower will give their opinion, but I am not one.

You probably have the same opinion that I have if considering adding plant supplements, choose lower known values and increase to a higher if needed as removal is often difficult or impossible without plant death. If you already have your potassium level where you think it will be ok, you can still consider the addition of the borax.
Borax and potassium oxide were used in the report:  http://krishikosh.egranth.ac.in/bitstream/1/5810000191/1/Nakka%20Sathi%20Babu.pdf   on page 28

Notation for the treatments Levels of boron and potassium
• T1: B1K1 25 g borax/palm + 900 g K2O/palm
• T2: B1K2 25 g borax/palm + 1200 g K2O/palm
• T3: B1K3 25 g borax/palm + 1500 g K2O/palm
• T4: B2K1 50 g borax/palm + 900 g K2O/palm
• T5: B2K2 50 g borax /palm + 1200 g K2O/palm
• T6: B2K3 50 g borax/palm + 1500 g K2O/palm
• T7: B3K1 100 g borax/palm + 900 g K2O/palm
• T8: B3K2 100 g borax/palm + 1200 g K2O/palm
• T9: B3K3 100 g borax /palm + 1500 g K2O/palm

page 28

Continue monitoring levels of the other Ca, Mg, Cl, Na, etc. etc. etc. and soil ph, moisture soil & atmosphere, aeration soil & atmosphere, light source, temperature, etc. etc. etc.

 

« Last Edit: March 19, 2018, 09:29:07 AM by palmcity »

Coach62

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Re: Coconut deficiency and treatment
« Reply #5 on: March 19, 2018, 08:48:04 PM »
I looked at my palms, are you SURE it's a deficiency?  I feed mine pretty well, and the bottom most fronds do start turning yellow and look chlorotic.  I can't help but wonder, is that the tree just pulling out the nutrients before it drops them??

Just a thought, am I totally off base here?
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KarenRei

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Re: Coconut deficiency and treatment
« Reply #6 on: March 19, 2018, 09:20:10 PM »
I looked at my palms, are you SURE it's a deficiency?  I feed mine pretty well, and the bottom most fronds do start turning yellow and look chlorotic.  I can't help but wonder, is that the tree just pulling out the nutrients before it drops them??

Just a thought, am I totally off base here?

That question can of course be turned around - are you sure yours aren't deficient?  ;)  Potassium deficiency is reportedly very common in palms.

From what I've read, the best way to assess the severity of potassium deficiency (rather than whether there's a deficiency at all) is the number of leaves on the tree.  The number steadily declines with a progressively worsening potassium deficiency, until the tree dies (severe potassium deficiency can be fatal).  It's normal for a tree to lose leaves, but they should last for several years each (again, according to what I've read).   I don't think these fronds are several years old (although I haven't exactly been hanging a "this frond sprouded in March 2018" tag on them  ;)  ).

Still, you're right that I don't know for sure what the problem is, and this is all "educated guesswork".  I could take samples and send them in for testing, but the last time I did a soil test at the very least it took them over a month to get back to me  :Þ  And the question comes, what's the most useful to test... new fronds, middle aged fronds, fronds in early stages of chlorosis, late-stage chlorosis, necrosis.... or soil?  And if soil, at what depth?  Each additional test = more money.

Sigh... I so wish I had my own lab here so I could do this myself  :( 
« Last Edit: March 19, 2018, 09:37:23 PM by KarenRei »
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Coach62

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Re: Coconut deficiency and treatment
« Reply #7 on: March 19, 2018, 11:23:51 PM »
This article says basically what I said, but that does NOT make it correct of course.  http://homeguides.sfgate.com/palm-fronds-turn-yellow-97748.html

No, I have not had mine tested, so I can't say for sure that I don't have a deficiency, BUT I do have many dozens of palm trees, although only 3 coconut palms.  They get plenty of water, and I fertilize them regularly with expensive, high quality palm fertilizer with iron and micro nutrients. 

As far as palm fronds lasting a long time?!?!  I very strongly disagree with that.  I have queen palms, cabbage palms, royal palms as well as coconut palms, which I grew from seed.

I do not know how long they last, but I do know it isn't that long.

I guess I would suggest applying a high quality palm fertilizer at the recommended rate for AT LEAST 6 months, then reevaluate.  You can buy soil test kits that test PH, plus all major nutrients for very cheap, I find them pretty accurate when used properly.  These test PH, N,P, and K.
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KarenRei

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Re: Coconut deficiency and treatment
« Reply #8 on: March 20, 2018, 04:19:59 AM »
https://www.bioversityinternational.org/fileadmin/bioversity/publications/Web_version/108/ch02.htm

In "Chapter 1: Botany of the Coconut Palm", it states: " A leaf remains on the palm for about 3 years and thereafter, shed leaving a permanent scar on the trunk."  I've seen the same comment elsewhere on a number of respectable sources.

I also have to question some of the info in that SF Gate article - specifically, the claims...

 * ...that nitrogen deficiency is the most common palm deficiency, not potassium as the papers I've read state
 * ... that you should use the same treatment for a potassium deficiency as for a nitrogen deficiency (the pages I've seen elsewhere say to use potassium sulfate or potassium chloride to treat potassium deficiency in coconut palms)
 * ... that the primary symptom of potassium deficiency in palms is leaf spotting (AFAIK that only happens in some species)
 * ... that magnesium deficiency is a problem of palms not being grown in "palm soil", which is supposedly more magnesium-retaining. Particularly have to question that for palms which prefer sandy soils, aka those that are well draining (magnesium drains away) and have low cation exchange capacity.

That said, I'll consider the possibility that maybe this is nitrogen deficiency, with something else causing the necrosis (because nitrogen deficiency doesn't cause that) maybe?  I can at least state that there's no advanced nitrate deficiency, since young fronds are still dark green (advanced nitrate deficiency leads to whole crown yellowing).   I've broken up the recommended treatment for potassium deficiency into smaller doses, so I may try replacing the potassium sulfate in the next dose with potassium nitrate.

Do you have a soil test kit you can recommend?  I almost invariably won't be able to get it here, but I could order one, pay double its price for shipping and customs, and it'd arrive after a month or so.   ;)

« Last Edit: March 20, 2018, 05:13:16 PM by KarenRei »
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Re: Coconut deficiency and treatment
« Reply #9 on: March 20, 2018, 08:01:56 AM »
The last one I bought was at Home Depot. The chemicals come in little caplets. But, I did a search and there appears to be better kits out now, they look like a pool water test kit.

As far as fronds lasting 3 years, I guess I'll tag a couple and see. I didn't actually study it, I was just basing that off of how often I have to remove dead fronds.
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Re: Coconut deficiency and treatment
« Reply #10 on: March 20, 2018, 04:38:47 PM »
I advise to not remove fronds from young coconuts. I have keiki that are about 2 years of age in large grow bags. They are still holding onto some of the first leaves they made. Removing these before they fall off naturally can create weak trees.
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Re: Coconut deficiency and treatment
« Reply #11 on: March 20, 2018, 04:41:19 PM »
With several species of palms and Annonas, I have seen both yellow spotting and marginal necrosis, usually on different leaves, and I have attributed both symptoms to Potassium deficiency;  but I have no explanation.
Har

KarenRei

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Re: Coconut deficiency and treatment
« Reply #12 on: March 20, 2018, 06:29:30 PM »
I advise to not remove fronds from young coconuts. I have keiki that are about 2 years of age in large grow bags. They are still holding onto some of the first leaves they made. Removing these before they fall off naturally can create weak trees.

Indeed - that's been my instinct, and I've seen it backed up by research; when a plant is going to lose tissue such as a leaf or frond, it leaches mobile nutrients out of it first - so by cutting off sickly fronds you can actually make a deficiency worse.  Now, of course, once they're fully necrotic and dessicated, the plant isn't going to be recovering any more nutrients from them... so you might as well return them to the soil to decompose so the plants can have a go at the remaining (esp. immobile) nutrients  :)

I finished up about 2/3rds of the supplementation I intended this evening, and there was some drainage out of the bottom of the pot, so I know that the nutrients should have penetrated all the way through.  But it also means that the poit is saturated all the way through.   So I think I'm going to back off for at least a week, when it'll then be time for the normal monthly feeding, which I'll just enlarge to finish off the supplementation.  Then it'll just be a matter of waiting and seeing how things progress.

I noticed an observation this evening which is that not just the leaflets are yellowing, but the petiole as well... sort of a spotty yellowish green.  But AFAIK that's also a symptom of a frond having insufficient potassium, that it's not just confined to the leaflets.  AFAIK!  :)

(Also think I accidentally created sulfuric acid in my microwave this evening, but that's an entirely different, unrelated story  ;)   ).
« Last Edit: March 20, 2018, 09:13:39 PM by KarenRei »
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Coach62

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Re: Coconut deficiency and treatment
« Reply #13 on: March 20, 2018, 09:02:21 PM »
I advise to not remove fronds from young coconuts. I have keiki that are about 2 years of age in large grow bags. They are still holding onto some of the first leaves they made. Removing these before they fall off naturally can create weak trees.

I know this, as I stated clearly above already.  I said DEAD, meaning ready to fall off, dry, hanging on by a thread.....
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Re: Coconut deficiency and treatment
« Reply #14 on: March 21, 2018, 08:44:26 AM »
I didn't read through all the suggestions made so far so I don't know what advice has been given. However, I have a dozen very healthy coco palms here, the oldest is about eight years and fruiting. Following the local customs here, the only supplementation I have given them is a couple of handfuls each of crude sea salt maybe once a month spread around the trees. Made sense since the palms growing at the beaches seems very happy and fruitful to me. As far as frons are concerned, I always cut the dying ones which seems to stimulate the trees to relatively quickly grow more leaves. I'm no botanist but it sure works for me. BTW, I'm located at 1000 meters where it's much cooler and they're are few coco palms growing.
« Last Edit: March 21, 2018, 08:47:05 AM by Doug »

KarenRei

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Re: Coconut deficiency and treatment
« Reply #15 on: March 21, 2018, 09:34:18 AM »
Unfortunately there are some differences to plants in pots vs. in-ground, since there's vastly more resources available to the roots in-ground.  But it's good to know that adding salt is a good thing; it just feels so weird to be adding salt to soil!   Apparently symptoms of chlorine deficiency in coconut palms includes cracked fronds, which I haven't observed - but it can also hinder root growth, so better safe than sorry  :)

You know.. hmm... every now and then I pick up a bucket of beach sand to use in my potting mixes to improve drainage, and the first step I always do is to drain it and then run it through several changes of water to leach all the salts out.  Perhaps I should be draining it into my coconut's pot the next time  :)  Then it would be actual sea salt rather than pure sodium chloride being added.
« Last Edit: March 21, 2018, 11:18:45 AM by KarenRei »
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Re: Coconut deficiency and treatment
« Reply #16 on: March 21, 2018, 12:48:46 PM »
In the central Amazon region, a thousand miles from the sea, I was told that Coconuts produced better if a small cloth bag of salt were tied up near the top of the canopy.  I never actually saw that done--- and Coconuts often didn't seem very thrifty or worth having.
Har

KarenRei

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Re: Coconut deficiency and treatment
« Reply #17 on: March 30, 2018, 09:12:29 AM »
I think I may have identified a new potential contributing factor: temperature.

When the problems (not just with the coconut, but several other plants) started occurring, I had identified a couple factors as possible causes - giving a little ammonium-based fertilizer, an outbreak of fungus gnats,etc.  And around that time I had realized that I had been significantly underfertilizing some of my plants.  But one change that didn't cross my mind was that I had started leaving the door to the growth tent open.

I've had problems with temperature before in the opposite direction - I've lost more plants than I care to admit due to overheating, particularly in the summer, from closing the tent door too much and/or closing the room door.  So since then I've always erred on the side of too little heat.  But I've also gotten  complacent and had stopped daily monitoring of the temperature.  Something clicked to me yesterday when I stopped and thought about which plants had started doing poorly:

 * Coconut
 * Salak
 * Garcinias
 * ... etc.  Basically, all plants that want high temperatures.  Now, it wasn't "cold" in there; I'm not even capable of achiving low temperatures in there, due to all the lights  ;)  But when I took some measurements, in places it was as low as 21°C/70°F in places, and had clearly been "cool" for quite some time.  That's not devastatingly cold, but it should be cool enough to reduce root effectiveness.  Coconut, for example, prefers average temperatures around 27°C/81°F, and my garcinias should prefer around 30°C/86°F on average. .

I'm still more afraid of overheating than having temperatures get too low, because it's too easy to happen accidentally.  But I need to be letting the temperatures get higher if I want to ensure proper root vigor.
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