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Topics - KarenRei

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Ran into a very interesting paper researching coffee productivity (was actually searching for artocarpus response to light at the time, but I'll take it!)

Key takeaways:

 * Photosynthesis rates of sun-adapted leaves are about 80% at 500 umol/m/s, 90% at 750 umol/m/s, and 100% at 1300 umol/m/s. Full sun is around 2200 umol/m/s; the extra sunlight only serves to inhibit photosynthesis
 * This is amplified by means of the fact that coffee leaves live longer in shade, and thus less energy needs to go into their production
 * Opposing this, however, is real-world data showing that coffee production is higher in the sun than the shade - multi-year yields are just under 80% of max in full sun, 100% in 75% sun, a bit over 80% in 50% sun, and around 30% of max in 25% sunlight.  "Good year" yields are even better for full sun - nearly as good in 100% sun as 75% sun, and nearly 4 times more in full sun than 25% sun.
 * The reason for this is that the internode length increases in the shade, and thus fewer flowers are produced (note: not discussed in the paper, but if one wants to counter this, blue light is known to reduce internode distances).
 * Somewhat (but not significantly) offsetting this is lower fruit drop in shade coffee.
 * Because energy is abundant in shade coffee, but full sun coffee produces more fruit, shade coffee yields a higher-quality fruit, while sun coffee stresses itself out to the point of resulting in a partial alternate-bearing habit.

Citrus General Discussion / Recommended citrus for a public garden
« on: June 06, 2018, 08:08:35 AM »
So, as you probably know, I'm involved in a project to build a series of greenhouse domes in Reykjavk combining normal commercial space (restaurants, coffee shops, workplaces, etc) with active cultivation of exotic tropicals. And to that end I've been accumulating data about every "interesting" tropical edible under the sun that comes onto my radar, to aid in plant selection.  Since I've recently been working on citrus, I thought I'd ask: what citrus varieties would you recommend?  :)  We're as always looking for the best mix of taste, productivity, precociousness, attractive appearance / scent, ease of cultivation, interesting history/stories/other uses, and so forth. Fast  growing and shade tolerant are plusses, but not essential  :)  Small fruited is probably better than large fruited, as it makes it easier to offer "samples", but this is further down the priority list.

So far the ones that sounded interesting to me were:
 * Finger limes (shade-loving and neat appearance, although need to be careful with cultivar selection to avoid a soapy taste)
 * Bergamot Orange (everyone knows it because of Earl Grey, etc, but few know the actual fruit)
 * Kaffir Lime (the leaves being if anything more in-demand than the fruit)
 * C. limon "Kannu'on" - got to love any lemon whose smell gets described as "Fruit Loops cereal"  ;) Most lemon cultivars I've seen info on are described as producing all year, although I don't know about this one.
 * Meyer Lemon - just because they're generally well appreciated, as far as "lemons" go.
 * Buddha's Hand Citron (I also considered etrog, but after talking with a rabbi realized that I wouldn't be able to grow them kosher, so there would be no point)
 * Mandarins - they're not spectacular or exotic, but they're a Christmas tradition here.
 * Ponkan - like giant mandarins, so see above.
 * Blood oranges - anthocyanin-rich and look neat.

Anything else that should go under consideration?


Maximum net CO2 assimilation of most citrus cultivars saturates at relatively low irradiance (600 to 700 umol m-2s-1), which is only 30 to 35% of full sunlight (1500-2200 umol m-2s-1) on a typical growing season day (Syvertsen, 1984). The excess radiant energy predisposes plants to photo-inhibition, heat stress and stomatal closure, resulting in a reduction in net photosynthesis (Pn), the ultimate source of fruit soluble solids.

Experimenting with grapefruit, they found no meaningful change in yield for using 50% shade cloth from Apr-Jul, but a 35% yield improvement for using 50% shade cloth from Jul-harvest.  A caveat that they encountered was that while reducing light levels was good on sunny days, on dimmer days it reduced the light levels down to below the plants' limits, and thus reduced photosynthesis. So "adaptive" shade might have been even better.

What's your experience with shading?  I had always thought that, with a few notable exceptions (such as finger limes), citrus trees were full sun plants that were significantly adversely impacted by shade.  But this argues otherwise.  Could citrus be effectively intercropped?

Tropical Fruit Discussion / Wow - neat trick, Pachycereus.
« on: June 05, 2018, 09:17:26 PM »
I wish more plants had figured this one out!

Right now I'm in the middle of researching good edible cactus.  And honestly, Pachycereus pringlei (Cardn) isn't at the top of the list.  It's not that the fruits are tasteless or insipid like many cactus fruits - they're sort of like molasses flavoured, somewhat dry saguaro fruits.  But it's one of those cacti that has to get big to fruit, like its Saguaro cousins (at least it's faster growing than Saguaros!). It's likely the largest cactus in the world, nearly 20 meters tall and over a meter in trunk diameter. Extremely massive; you don't want to run into something like this with your car.  ;)

But that's not what I felt the need to mention.  :)

We all know of plants that have symbiotic relations with nitrogen-fixing bacteria.  They release chemicals in the soil which encourage the microbes to migrate toward them, then enclose them in nodules, where they nurture them. We also know other plants that form root associations with mycorrhizal fungi; if these fungi are in the soil, the fungus infests the plant's roots, "stealing" sugars, but in exchange breaking down bound-up minerals in the soil for the plant to use.  P. pringlei takes it a step further. It can grow on bare rock because of its associations with nitrogen-fixing bacteria and rock-decomposing fungi, but it can do so anywhere because it packages these bacteria and fungi into its seeds.  Which I guess is a big advantage in a desert; things are so sparse, you can't count on the "soil" just happening to have what you need on-hand!  A bird eats the fruit, leaves its droppings with the seeds some great distance away, and it's guaranteed to have the helper species it needs on-hand.

Has anyone ever heard of any other plants doing this?

Tropical Fruit Discussion / Langsat incense
« on: June 04, 2018, 10:33:01 AM »
So, I was looking at my compost pile today, and - noticing some langsat rinds on the top - I recalled reading about how dried langsat rind can be used as incense.  So I decided to try it out.

One quick recommendation - don't leave them in huge chunks that pack poorly together, cut them up to the degree necessary so that they pack in reasonably well together.

One thing I was really impressed with was how it burns.  There's apparently a flammable oil in the rind - you can see it bubble out - and it maintains this perfect nice, slow, steady smouldering - just what you want in an incense.  Nice pretty wispy waves of smoke come off of it.  Unfortunately, the scent on its own wasn't remarkable - there was maybe a hint of langsat scent in there, but it was mainly just a smoke scent.

I'll have to try this again, but this time dripping some essential oils onto the rind to give a more interesting aroma. But as far as reusing waste goes, this one really seems to work.

ED: Found a bit more usable rind and tried it with some essential oils.  The oils turned out to act like an accelerant - which in a way is good to an extent, as it helps all of the pieces catch fire, but it also burns them up faster - and you don't really want to be burning *off* your essential oils either.  I almost wonder if the best option might be something like langsat + a little essential oil "ignition" fluid + dried citrus peel, to get some sustained essential oil release in there.

One thing that's kind of neat is that for a while you can get this "floating fire" effect, where it looks like the air over the langsat is burning, not the langsat itself:

If you like incense, it's worth giving it a shot  :)

I'd always believed that Aztec Sweet Herb (formerly, Lippia dulcis, now Phyla scabberima), the source of the sugarless sweetener hernandulcin, also contains significant amounts of the toxic substance camphor, and thus should only be consumed in small amounts, and in particular be avoided by pregnant women.  However, I just ran into this interesting paper from 1996:

Apparently the first studies of the plant involved samples collected in Tlayacapan (where they're known for use in treating dysentery and abdominal inflamation), and they identified hernandulcin as the sweetening compound, in significant quantities. A followup study involved a mixture of plants collected in Tlayacapan and herbs purchased in Mexico City, being sold as an abortifacent. They strangely found little hernandulcin (although their analysis method may have been to blame), but also found that the essential oil was 53% camphor, creating the health concerns. This study here analyzed plants collected in Orocovis, Puerto Rico and found ample hernandulcin (36% of the essential oil) and no camphor whatsoever. It also yielded much higher essential oil contents than the Mexican plants had.  In Puerto Rico - and, from what we know of the Aztecs' usage of the herb - there were no abortifacent properties attributed to it.  The author suggests several possibilities, but perhaps the most probable is that the abortifacent-variant sold in Mexico was misidentified and was not L. dulcis / P. scabberima.  It might also answer the paradox of how you could have a sweet-tasting herb containing so much camphor, as camphor is bitter tasting.

I need to research this some more later, but I'll call this good news for fans of natural sugarless sweeteners  :)

I'm curious, who here (who sells live plants) is under phytosanitary control and certified for their export?  I know a number of people here as seed sellers (and have purchased from some before), but have not previously had need to purchase live plants so have not looked into it.  I'd much rather to purchase from people here than from elsewhere  :)

In general, we can import pretty much anything tropical.  E.g. nobody's worried about the "Icelandic citrus industry" being hurt by citrus psyllid or about strawberry guava becoming invasive or whatnot  ;)

Tropical Fruit Discussion / Aaaargh!
« on: May 02, 2018, 08:39:38 AM »
So, I recently had a number of plants showing signs of potassium deficiency and struggling.  A soil potassium test revealed that it was low (nitrogen was high, phosphate normal).  So, I gave them a nice helping of potassium sulfate from a bag I got on ebay long ago and but had only recently started slowly using up (not in formal product packaging, just a labeled ziplock).  They all got worse, and a few that I'd had for years died. I was baffled, but something had been eating at me.  When I bought a big bag of potassium sulfate at a store here (since I was running low on the ebay stuff), the compound didn't look like the contents of my old ebay potassium sulfate.  So I set up a potassium test and sprinkled some into the test liquid.  No colour change.  Then I set up a nitrogen test and sprinkled some in.  Rapid bright purple, off the charts.  It's some bloody ammonium compound.  Ammonium, a compound that  makes potassium deficiency worse, and when over applied is toxic.  Aaaargh!

Well, this also probably explains the calcium deficiency in one of my bananas too that doesn't seem to want to go away.  I'd been giving it the "potassium sulfate", and yes, excess ammonia causes calcium deficiency too  :

Tropical Fruit Discussion / Native habitats spreadsheet
« on: April 30, 2018, 07:55:55 AM »
So, I made a thing  ;)

Still very much a work in progress, but I thought I'd share: as a tiny portion of the database project I've been working on, I wrote a program that parses plant habitat descriptions and combines that with climate data to determine what sort of native environments they're grown in (this is combined with some curated data concerning what conditions the plants are known to like growing in.).    It looks at the plant's native altitude range and only includes points within the habitat areas which are within that altitude range.   If it can't find any locations that match the stated altitude in the stated range (e.g. the resolution is too coarse), it uses what data it did find and adjusts temperature, etc for the altitude difference. 

Now, some caveats.

1) It's a computer without a brain having to read text.  Subtlety will pass it by.  I've tried to include common edge cases - for example, "Located in X, not found in Y" - it'll see Y but not parse it.  It also tries to, when it sees "Found in X (Y)", where either X or Y is a subregion of the other, only parsing the subregion, not the whole.  But expect some mistakes.

2)  A lot of the mistakes are in the habitat description itself. For example: Artocarpus lakucha comes up with an average wintertime low in its range of 6,1C.  Now, we know that it's not native to such cold climates. How did it come up with that?   Well, the range description is "E. Asia - Malaysia, Sumatra, China, India, Nepal, Sikkim, Myanmar, Laos, Vietnam, Indonesia, Philippines".  So it's looking at the climate of all of those - including all of China.  We know in reality that you'd only find it in the warmer parts of China, but that's not what the description says.  So, vaguery = bad  ;)

Feel free to improve habitat descriptions to be more accurate!  You can use countries, subregions, cities, etc.  Just try to make sure that you don't name a place that has a more major (population, significance, etc) area with the same name!  It understands adjectives such as cardinal directions (including e.x. "northeast", but not "northnortheast") as well as "central".  Scattered city listings are just fine.  Let me know when you make any changes of significance and I can re-run it.

3) It does not understand the common wording "through" - e.g. "Portugal through Greece".  It will only look at the endpoints.  Again, feel free to improve this by being more specific.

4) The data behind it is the same data behind this site:

But some of that data doesn't match other sites.  For example, they show a much dimmer winter in Manaus than you get when you punch Manaus into PVWatts.  I'm still trying to reconcile that.  Another example is in humidity; the average humidity figures seem to match the figures you'll see reported for average humidities for cities on Wikipedia, but when you go to daily weather histories on Weather Underground, it feels a bit off, particularly on daytime humidity.  Again, not sure how to reconcile that; this is just coming from the data I'm given.

5) There's still a good number of duplicate / synonym species that I need to work out, and a LOT more curating that needs to be done.  A known bug is that sometimes it'll list "kill temperatures" as "minimum acceptable temperatures", although it's generally very obvious when it does that.

6) It ignores everything up to the first dash (if an "early first dash" is present), to avoid parsing e.g. whole continents.

All that said... enjoy  :)  Don't be too hard on me about errors, this is a first draft (there might even be some alignment errors pasting into Google Docs!  I haven't had much time to go over it). Just point them out, and where you can and/or improve the data (anything at where it says "Known preferred climate" or to the right) and let me know what you changed (otherwise it might accidentally get wiped out when I do future runs!)  I see one issue I'm going to check into this evening, where an acacia is getting a lower temperature rating than I'd expect.  I want to make sure that at least the algorithm is doing everything right, even if some of the habitats are poorly described  :)

(I have a LOT more data I'm collecting, but I'm still going through it)

Hi all! I was in a meeting with our project manager the other day discussing various plant possibilities. She likes the idea of having lianas (we have a huge amount of room to fill and want to do so as quickly as possible, with no practical limits on how much weight the (steel, concrete) structure can bear) but she wasn't sure about how quickly we could get them established.  I was able to answer her questions about a lot of other vining species, but I really have no clue with the big liana species like you find in Apocynaceae.  Based on other tropical vines I'd WAG it around 3m a year once established, but what do you growers find?  And how quickly do the vines thicken up?  I know this is a really broad category, but any datapoints you can add would be great  :)  We'll have a mix of full sun, partial shade, and full shade; summer sun is 24/7 here, while winter would receive an artificial "sun" of nearly half a megawatt of lighting  ;)  And we have both dry and wet domes to fill, with various microclimate zones in each. No winter, and dry seasons only where needed..

Note that while the potential of fruit is important, even if it ultimately fails to fruit, that's fine; we just need to get some things large and impressive established in the early years. Actual yields in the earlier years would be from smaller, precocious plants, while plants that need time to grow large get their chance to do so.  Any initial fast-growers that ultimately "fail to perform" would be on the chopping block  down the road to make way for other species that want their sunlight  ;)  Of course, if they yield fruit that goes over well, then they can earn their keep  ;)

Tropical Fruit Discussion / Encouraging acerola fruit set
« on: April 21, 2018, 09:49:58 PM »
So, I've finally figured out the recipe to making my acerola flower: fertilize well, calcium-rich / higher-pH soil, good root aeration, significant dry period, then water and prune (no clue why pruning encourages flowering, but it sure seems to).  Right now my acerola has more flowers on it than it's ever had on it in its whole life put together.  Yet at least so far I'm not sure if I've gotten any fruit set. Are there any good tricks for that?  I've done some trying to pollinate with a sponge paintbrush, some tree shaking, and last night I have it a heaping serving of potassium sulfate, hoping that will help.

I love acerola, and they're quite good for you too, so if even a small fraction of these flowers set fruit, I'll be quite happy  ;)

It's weird that I never seem to see any pollen grains.  I can see the anthers in the flowers and they're bright yellow, but no yellow "dust" ever seems to come off of them.  I'd break out the microscope but the eyepieces are a bit messed up at the moment...

About to harvest some coffee, and I'm wondering... is there anything worth doing with the flesh of coffee berries?  I've sampled them before, and they're... underwhelming.  Sweet, but a leafy taste.  Wondering if there's any application in which they're actually good. Or whether I should just wet ferment the cherries to try to impart a sweeter flavour to the "beans".

Much appreciated by natives in central Australia, particularly the Aranda people. Woody fruits up to 9cm in diameter; flesh inside is sweet, oily and milky, with a taste reminiscent of coconut, and very nutritious.

C. pomiformis seeds are tiny, round, soft, and have a short lifespan.

Shade tolerant. Dioecious. Fertilized by insects. Cannot be grafted or air layered, but comes true from seed.

Available for only a short period of time; get 'em before they fly out the door!

I'm finding conflicting information about the odor in the big pom-pom flowers of Parkia biglobosa.

As one would guess, they're primarily bat pollinated (although capable of bee pollination), and so - reportedly - have a strong scent, like most bat-pollinated flowers. However, most bat-pollinated flowers have a strong bad scent.

This paper:

... describes the scent of other Parkia species as "foetid, fruity or like cow manure", due to sulfur compounds, but finds no sulfur compounds in P. biglobosa. Their description of the "strong floral scent" of P. biglobosa (which peaks in the evenings) is "A heavy, sweet and somewhat stuffy scent".

However... this here:

... says that the flowers "may smell foetid and fruity like cow manure"

My *suspicion*, due to the striking similarity of the wording between the two sources, is that the World Agroforestry site is just getting that from a description of the smell of Parkia species' flowers in general, rather than specific for P. biglobosa. Specifically, the first paper cited "Wee & Rao, 1980; Hopkins, 1983; Gdnmeier, 1990" for that description, so I imagine that World Agroforestry gets that description from them too.  But this is just a suspicion on my part.

Has anyone here ever smelled a P. biglobosa flower?

Also, while were on the topic of P. biglobosa, I've seen conflicting information about how big they are when they start to flower. I've seen one person say "Trees start flowering at 5 - 7 years while still comparatively small.", suggesting that they might even be able to be grown in a pot; while another source says that they're quite large when they fruit, which begins at 5-10 years; and another source says that they grow up to 1 meter in the first year and up to 7m in the first 6 years.  Is that "small size at first flowering" only if you dwarf them?

Tropical Fruit Discussion / Coconut deficiency and treatment
« 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 24C (75F), day and night, all seasons, at all depths.  Air temperatures vary, and increase with height, but probably average around 30C (86F), 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?


Casearea quinduensis   -   RG   Small tree, green fruits almost identical to those of C. obovata

All well and good.  Except:

Red List Category & Criteria:   Extinct ver 2.3

Has anyone asked Jim about this before?  Either his ID is wrong (most probable), or he's selling seeds of a species that's thought to be extinct.

I'm finding some rather limited - and perhaps incongruous - data on the yields of jaboticaba species and their relatives (optimum soil / sunlight / feeding conditions), and I'm looking for feedback  :)

So far I've only found two references that seem of utility: one said that Myrciaria dubia / Camu Camu yields 12t/ha in cultivation (rather low by fruit standards, about 40% more than Mangosteen - a standard low-yielding fruit).  The other states that a mature Jaboticaba (apparently Sabara) yields 1000 pounds (~400kg) in Brazil.  Going with the assumption that by mature they mean "huge", and going with 9 meter (30 foot) trees, spaced 9x9 meters apart (from the same source: "He felt that 30 feet was the correct spacing without pruning"), this works out to around 50t/ha, which is a very large yield (say, high density oranges grown under optimal conditions, or double that of high density mango cultivation).

For you growing jaboticabas, what would you estimate yields would be for your various species/varieties, and what said "optimum conditions" would be?  I assume that you don't know t/ha figures, but I can work with any sort of figures - e.g. "The yield is similar to oranges", "I get about X pounds per fruiting and Y fruitings per year on a tree that's Z feet tall", etc.   :)  Even comparisons of annual yields between different jaboticaba varieties would be of use! 

(Note: per year, not per harvest  :)  )

Jim West has a species on offer, Clavija longifolia (mongon) (primrose family, Primulaceae), which like many of his species is somewhat difficult to find personal accounts of people growing it  (although not as hard as Casearea (Caesarea?) quinduensis(?)!).

Does anyone have personal experience with C. longifolia?  From extensive googling, I've come up with: it is a very aesthetically attractive plant, with a palmlike growth habit (2-4m) but a rosette of "broadleaf"-style leaves at the top, and cauliflorous fruiting habit.  The orange fruit appear to have a flesh that looks sort of like orange sherbert or caramel in pictures, with a thin, probably easily removed rind. Photos of the plant show it frequently growing (and fruiting) in varying degrees of shade, including some surprisingly deep, although I've found one picture that shows it in at least mostly sun if not full sun. Productivity looks relatively good relative to the size of its crown and the environments it's growing in. I did find one report that scarified seeds soaked for 36 hours took up to 4 months to germinate, with a 2/3rds seedling death rate, and that they apparently like their growing media constantly moist.  It reportedly has a good smell, although it's not clear whether that's the flowers or some other part, and how much of the year that's present. Habitat: "tropical forests in the Andes between 500 and 2000 m from Venezuela to Bolivia "  IUCN status: Near Threatened.


Anyone have anything to add about this species or genus?  The main thing I'm missing is fruit quality, and anything about cultivation difficulty/details, etc.  I know at least one person here has grown it (akanonui).

A gorgeous tree, with well rated fruit... yet the information I'm finding on it seems contradictory.  Just some examples here alone:

 * Says it's slow growing, and "doesn't exceed 2 meters height after 2 years".  Putting on a meter of height per year in a plant's first two years isn't slow growing at all.  How fast does it actually grow?
 * Says it succeeds in both sun and partial shade.  Yet I have trouble finding any pictures of it at all growing (let alone fruiting, aka "succeeding" IMHO)  in any sort of shade... pics generally show it growing in the middle of an open field.  Does it truly "succeed" in partial shade, and if so, how much shade?
 * Says it mainly grows in sandy or clayey soils, but also says that it prefers organic soils
 * The claims that large amounts acts as a laxative, and that large amounts cause a mild drunkenness, make for an interesting mental image.  So if you eat a large amount, you end up drunk on the toilet?  ;)

What's the actual deal with this interesting eugenia?

Tropical Fruit Discussion / Is White Sapote really *this* productive?
« on: March 10, 2018, 07:00:24 PM »
Some comparison numbers: A modern apple plantation, properly managed, yields about 65t per hectare of saleable apples, which is rather high by fruit yields.  Peppers are 20t/ha.  Papayas are 40t/ha.  Mangosteen is 8,5t/ha.  Etc. The highest that comes to mind, as far as fruits go, is babaco, at just over 100t/ha (banana is also huge - 60t/ha in the high intensity fields, 120t/ha in experimental conditions).  Most fruits are somewhere in the 10-20t/ha range.

From this:

"Mature trees can reach 15 to 18 m in height and produce 900 kg (2,000 lb.) of fruit per year. Thompson, (1972) reported a tree of 'Chestnut' produced nearly 2,700 kg (6,000 lb.) of fruit in 1971 in Vista, California. Grafted trees remain smaller and develop a better canopy than seedlings."

Looking at pictures of large seedling white sapotes shows that they're moderately "vertical" trees, 1,5-2x as tall as they are wide (unlike smaller/grafted trees, which are broader).  Let's say that they're planted on a square grid spaced at a distance of 1,3x their height; that should keep things nice and sunny for each tree.  For a 16m tree that's 130,6m per tree, or 76,5 trees per hectare.  900kg per tree is 69t per hectare - more than apples.  2700kg would be 207t/ha, which is just bonkers. 

Am I doing something wrong, or is white sapote crazy productive?

Tropical Fruit Discussion / Annona(ceae) productivity relative to sun
« on: March 06, 2018, 06:38:14 PM »
For most of the species I'm working on I have to do a lot of digging, but when it comes to annonas (and their relatives with traditionally annona-like growth habits, such as biriba), I imagine I can get a lot of great responses here:   In your experience, what's their relationship between sun and productivity?  My general sense - which could be totally off here - is that maximum yield is in full sun; "light shade" (say, a couple/few hours per day) may results in a (halved?) yield, and "partial shade"/"half shade" is little to no yield, with full shade being a dead plant.

Is this generally correct?  Are there any species exceptions to this? Some that yield as much or better in light shade, or can even fruit decently in half/partial shade?  Some that absolutely demand full sun, with a couple/few hours of shade being prohibitive to fruiting?

Tropical Fruit Discussion / Are pineapples really this heavy feeders?
« on: March 06, 2018, 06:02:18 AM »
I've been bad for many years about fertilizing, using a "That looks good" approach, that IMHO has generally left a number of my plants nutrient-deprived (but occasionally overdosed others). I'm looking to amend my wicked ways and - in addition to working on my plant db - have also been working on a fertilizer db, starting with some of the more "mundane" plants I grow.

Everyone knows for example that bananas are heavy feeders - my data for them suggests e.g. around 1kg of N per year per plant (1485kg per hectare) at maturity.  Yet, if one can trust this:

... it'd seem that pineapples dwarf that.  I find that commercial pineapple plantations are planted densely, 63400 plants per hectare. The data in the above link says to give fertilizer in amounts that equate to 0,086kg N per plant per year at maturity, or 5478kg per hectare per year - 3,6 times that of bananas.  Of course, pineapples don't stay at maturity for a whole year, but that's not the point; neither do bananas.  Are pineapples really such heavy feeders?  It's not just nitrogen - the ratios on phosphorus and potassium come out to be 4,8x and 1,5x, respectively.  By contrast, the figures for most annonas works out to be in the ballpark of 100kg nitrogen per hectare per year - less than 5% that of pineapples.

Is this right?  Are pineapples that hungry?  If so.... I have some pineapples to feed when I get home  ;)

Tropical Fruit Discussion / Don't throw away those passionfruit leaves!
« on: February 19, 2018, 04:21:27 AM »
So, the other day I was looking at a mess of old passionfruit leaves and thinking... "I wonder if there's anything I can do with these".  So today I googled it.  Apparently they're quite edible, used fresh, as a cooked green, and dried in tea (credited as being relaxing, as well as a number of other health effects).

Wondering whether there might be any adverse health effects, I went to to search for peer-reviewed research... and found just the opposite.  Apparently they're being studied for use as an anti-anxiety medication, with quite positive results.  Examples:


They're also effective as a cough suppressant and an antiasthmatic in the right doses:


... and much more... basically a general CNS depressant with some nice effects. And they're quite antioxidant:

And antiinflammatory:

P. incarnata (maypop) appears to be the most potent medicinal passiflora, but most species contain the active compounds to come extent (the closest to P. incarnata is P. caerulea, followed by P. lutea and P. capsularis). The compounds are not found in any significant concentration in the roots, stems, or flowers; the leaves appear to be the primary source. Concerning extracts, methanolic extracts are about 10x as potent as aqueous extracts (tea) - but aqueous extracts are still effective.  More to the point, it appears to be the water-soluble fraction of the methanolic extracts that has the effect.

I think when I get  home I'm going to be doing some pruning  ;)  Hopefully the taste is decent.

Tropical Fruit Discussion / White sapote seed safety
« on: February 11, 2018, 07:57:44 PM »
White sapote seeds are said to be fatally toxic.  The general public is well known for not reading signs and doing stupid things. How much of a risk is there of a person who paid no attention to information given killing themselves with a white sapote?  E.g.:

 * Are the seeds fatal when eaten uncrushed, and is it possible to accidentally or intentionally swallow them whole?
 * If they're only fatal when crushed / damaged, is it realistic that a person could accidentally or deliberately do so with their teeth?
 * I've found a couple mentions of seedless trees.  Are seedless cultivars commercially available? I've heard that Suebelle is seedless in about half of its fruits...

Also, while we're on the topic, does the fruit actually make you sleepy?

Tropical Fruit Discussion / Bignay: flowering and fruiting
« on: February 04, 2018, 05:48:15 PM »
Concerning bignay / Antidesma bunius:

1) Does anyone know the typical flowering and fruiting times?  The exact dates don't matter as much as the length of time in which they're in bloom / time the fruit is on the tree / length of the harvest.  The only thing I've found is one page mentioning that the harvest is 3 months.  The flowering time is particularly of interest as the flowers are foul smelling.

2) How long does the fruit last off the tree (shelf life)?

3) I'm finding mixed information about pollination.  The trees are dioecious, but one source says that female trees fruit abundantly without males, while another recommends one male for every 10-12 females.  What's the reality?

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