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Tropical Fruit Discussion / Coconut deficiency and treatment
« Last post by KarenRei on March 18, 2018, 08:47:26 PM »
As discussed here, somewhat offtopic:

... 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?
Tropical Fruit Discussion / Re: Time of plenty - look at these Pulasans
« Last post by Future on March 18, 2018, 08:45:53 PM »
We also have pulusan right now along with durian, rambutan, marang, Langsat, Kepel, etc.  It is our secondary season, something that doesn’t happen on the Pacific coast of CR.  Some of this guys have been driving 6-7 hours to come here for durian!

Don't tempt me...
Tropical Fruit Discussion / Re: kampong mauve sugar apple
« Last post by Future on March 18, 2018, 08:41:54 PM »

They are pretty good and at $4,80us/kg at the Mossman markets pretty reasonable.

Which market a Mossman?  Flashbacks to my 2012 visit...
No where in Bermuda is more than a mile from the ocean.  We had a winter storm that lasted several days, 5 days in a row peak winds got above 50.  At least hurricanes pass within a day or less.  Significant leaf burn on mangoes, breadfruit, sapotes.  However black sapote appears unfazed.

With so much repetition of being within "2 miles from the ocean" being great for mangoes, it makes me wonder if these areas has less salt spray or their prevailing winds move offshore..anyone attempt to desalt trees from ongoing winter storms?
Tropical Fruit Discussion / Re: Are these abiu flowers?
« Last post by cbss_daviefl on March 18, 2018, 08:18:45 PM »
Tropical Fruit Discussion / Are these abiu flowers?
« Last post by savemejebus on March 18, 2018, 08:11:00 PM »
For those in the know, are these abiu flowers? Been in the ground for a few years... I've seen these before but nothing came of them previously. Wondering if they're flowers.

Tropical Fruit Discussion / Fruit Punch baby mangoes... really red.
« Last post by savemejebus on March 18, 2018, 08:09:33 PM »
Thought this was kinda interesting. Of all the baby mangoes in the yard, the fruit punch seems to be super red comparatively speaking. First year of fruit punch fruiting.

Citrus General Discussion / Re: new greenhouse planning
« Last post by cory on March 18, 2018, 07:42:39 PM »
Brian, your greenhouse looks great!  Thanks for providing the update.

A nice showy fruit with thick creamy sweet flesh with raspberry and spice cinnamon notes, 8 seeds 16usd
Including shipping

"White sapote is not a preferred host for the psyllid (Halbert and Manjunath 2004; Westbrook et al. 2011). Since this plant is grown in California by rare fruit growers and horticulturists, mainly in regions where citrus is cultivated, and it may act as an alternate host for HLB, regulatory precautions are warranted."

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