Author Topic: Are pineapples really this heavy feeders?  (Read 4896 times)

KarenRei

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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:

http://edis.ifas.ufl.edu/mg055

... 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  ;)
« Last Edit: March 06, 2018, 06:31:58 AM by KarenRei »
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Mark in Texas

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Re: Are pineapples really this heavy feeders?
« Reply #1 on: March 06, 2018, 07:26:21 AM »
Might wanna look up Hawaiian commercial culture.  They are light feeders in the cup, sprayed with an over head boom.  Roots pretty much act as anchors.  They like a high N, high iron food and a slightly acidic soil.  I feed the soil with a slow release encapsulated food, 18-4-9 with micros and apply Dyna-Gro Foliage Pro, 9-3-6, in the cup.  1/2 tsp/gallon.   Since I lost a dozen or so pineapples to a heater failure I'm now restocking my collection with White Sugarloaf and White Jade and when the decent gold pineapples are available from Hawaii I'll be planting the "twistees".  They are delish!



pineislander

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Re: Are pineapples really this heavy feeders?
« Reply #2 on: March 06, 2018, 07:46:47 AM »
Quote
Pineapple (Ananas comosus var. MD-2) growth curves were developed based on fresh weight
(FW) and dry matter (DM). Absorption curves of macro and micronutrients were also calculated,
determining the amount of nutrients extracted in the growth and production phases, and total
accumulation of nutrients in the crop cycle. The curves showed a very low growth and nutrient
uptake trend in the first eight weeks. The nutrient demand was greater during the development
stage, particularly for N y K. In total, nutrients absorbed by 65 000 plants/ha were 639 kg/ha N,
70 kg/ha P, 1072 kg/ha K, 144 kg/ha Ca, 121 kg/ha Mg, and 55 kg/ha Fe.
Key words: absorption curve, growth curv

http://tierratropical.org/editions/issue-9-1-2013/growth-and-absorption-of-nutrients-in-pineapple-ananas-comosus-var-md-2-in-the-humid-tropics-of-costa-rica/

Just for a rough comparison, corn growers might require ~250 kg/ha N for high yields.

But remember for perspective, corn might take only 4 months, but pineapple 12 months or more.

KarenRei

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Re: Are pineapples really this heavy feeders?
« Reply #3 on: March 06, 2018, 08:24:42 AM »
Okay, these figures are much more believable; that was working out to an insane amount of fertilizer.  Either the page is wrong, or I'm reading it wrong.  Because they call for " 1 to 2 oz (30-29 g) or less of NPK every 8 weeks increasing the amount as the plant grows (Table 2).", with Table 2 going up to 5-8oz.  So multiply that by 6 1/2 feedings... it's like 2lb/0,7kg of 6-6-6 to 10-10-10 per year.  That's an insane amount of fertilizer for a plant that is only allocated ~0,15 m² of ground space.
« Last Edit: March 06, 2018, 11:22:14 AM by KarenRei »
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FruitFreak

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Re: Are pineapples really this heavy feeders?
« Reply #4 on: March 06, 2018, 11:33:55 AM »
IMO even more important than supplemental nutrients is providing them with a nutrient rich organic medium with consistent supply of moisture.  I've been placing twisties directly in mulch and they are starting to look really good.  How the fruit turns out remains to be seen.
- Marley

KarenRei

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Re: Are pineapples really this heavy feeders?
« Reply #5 on: March 06, 2018, 12:48:55 PM »
IMO even more important than supplemental nutrients is providing them with a nutrient rich organic medium with consistent supply of moisture.  I've been placing twisties directly in mulch and they are starting to look really good.  How the fruit turns out remains to be seen.

My understanding is that pineapples are obsessed with good drainage, which would run contrary to a rich organic medium that stays constantly wet. 
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Ulfr

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Re: Are pineapples really this heavy feeders?
« Reply #6 on: March 06, 2018, 03:50:47 PM »
IMO even more important than supplemental nutrients is providing them with a nutrient rich organic medium with consistent supply of moisture.  I've been placing twisties directly in mulch and they are starting to look really good.  How the fruit turns out remains to be seen.

My understanding is that pineapples are obsessed with good drainage, which would run contrary to a rich organic medium that stays constantly wet.

Organic matter increases drainage in heavy soils. Drainage moves standing water, doesn’t mean the soil won’t stay moist though (which it will with organic matter as said above).

I assume it’s standing water (either visible or subsurface) that is the problem with pineapples?
« Last Edit: March 06, 2018, 03:53:13 PM by Ulfr »

KarenRei

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Re: Are pineapples really this heavy feeders?
« Reply #7 on: March 06, 2018, 03:54:44 PM »
I guess I'm too used to pot culture where heavy soils (aka clay) basically don't exist unless you want them to  ;)  In my world, sand, perlite, and pumice increase drainage but decrease water retention; general organic matter / compost / peat / etc (in addition to vermiculite) increase water retention but reduce drainage.

The upside is no clay.  The downside is, unless you have (proportionally expensive) air pots, you have poor soil aeriation to start with.  Plants like coffee and bananas don't care, but you have to really watch those mango roots...
« Last Edit: March 06, 2018, 03:57:47 PM by KarenRei »
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WGphil

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Re: Are pineapples really this heavy feeders?
« Reply #8 on: March 06, 2018, 04:38:35 PM »
27 pineapple among the plants.  I’m going to have to expand.





FruitFreak

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Re: Are pineapples really this heavy feeders?
« Reply #9 on: March 06, 2018, 04:53:02 PM »
IMO even more important than supplemental nutrients is providing them with a nutrient rich organic medium with consistent supply of moisture.  I've been placing twisties directly in mulch and they are starting to look really good.  How the fruit turns out remains to be seen.

My understanding is that pineapples are obsessed with good drainage, which would run contrary to a rich organic medium that stays constantly wet.

Your understanding is correct that pineapples enjoy well drained soil.  They seem to be almost like pitaya being that they can handle very dry but seem to thrive with a consistent moisture.  There is also a fine line when it comes to watering all plants and trees.  Mine get 1hr of rotary overhead each day and are doing great.  Happy with the results of growing them in mulch so far but am curious to see how the fruit will taste.
- Marley

Evildeadguy

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Re: Are pineapples really this heavy feeders?
« Reply #10 on: March 06, 2018, 05:04:15 PM »
i only feed my pineapple plants once a month and they do great i end up with some nice size pineapple plants and pineapples i grow just about all my pineapple plants in pots... the part of florida i live in pineapple plants don't seem to grow well in the ground i end up with smaller pineapples when growing in the ground as to growing in pots
Pineapples i Grow: Natal Queen

Mark in Texas

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Re: Are pineapples really this heavy feeders?
« Reply #11 on: March 06, 2018, 06:02:41 PM »

My understanding is that pineapples are obsessed with good drainage, which would run contrary to a rich organic medium that stays constantly wet.

My mix is about 75% inorganics, 25% organics.  They must have good aeration that doesn't hold water for long.

TheWaterbug

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Re: Are pineapples really this heavy feeders?
« Reply #12 on: March 07, 2018, 01:18:12 AM »
Roots pretty much act as anchors.


I keep reading this, but then I de-potted one of mine after harvest, and it looked like this:





That looks like a pretty extensive root system. I'm going to de-pot another one, soon, out of a 19" pot (about 11 gal) and see if it's filled that up with roots, too.
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Mark in Texas

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Re: Are pineapples really this heavy feeders?
« Reply #13 on: March 07, 2018, 08:03:14 AM »
Roots pretty much act as anchors.


I keep reading this, but then I de-potted one of mine after harvest, and it looked like this:




That looks like a pretty extensive root system. I'm going to de-pot another one, soon, out of a 19" pot (about 11 gal) and see if it's filled that up with roots, too.

Mine look like that too.  My pineapples in 3 gal. pots are root bound come fruiting time.  Would be interesting to try out a root pruning system like Rootmaker or copper laden latex paints.

simon_grow

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Re: Are pineapples really this heavy feeders?
« Reply #14 on: March 07, 2018, 12:14:53 PM »
My pineapples are also like that with extensive root systems

Simon

Mark in Texas

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Re: Are pineapples really this heavy feeders?
« Reply #15 on: March 08, 2018, 08:00:51 AM »
Having two in a pot doubles your root mass too.

OCchris1

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Re: Are pineapples really this heavy feeders?
« Reply #16 on: March 09, 2018, 01:57:28 AM »
I too have noticed this with my pineapples. They go from no roots to holy crap that's a ton of roots! Quickly. I have about 20 that are in dire need of planting or repotting. Chris
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lebmung

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Re: Are pineapples really this heavy feeders?
« Reply #17 on: March 10, 2018, 04:00:21 PM »
I overwintered my pineapple in basement at 50F for 3 months, they did just fine, not lose, but rarely watered them 2 times the whole winter. They are very hardy beasts.

Mark in Texas

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Re: Are pineapples really this heavy feeders?
« Reply #18 on: March 11, 2018, 11:17:25 AM »
I overwintered my pineapple in basement at 50F for 3 months, they did just fine, not lose, but rarely watered them 2 times the whole winter. They are very hardy beasts.

Yep, the quickest way to induce root rot when temps occasionally dip to 35F like my greenhouse does is to water.

KarenRei

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Re: Are pineapples really this heavy feeders?
« Reply #19 on: March 11, 2018, 12:16:42 PM »
I overwintered my pineapple in basement at 50F for 3 months, they did just fine, not lose, but rarely watered them 2 times the whole winter. They are very hardy beasts.

Yep, the quickest way to induce root rot when temps occasionally dip to 35F like my greenhouse does is to water.

I've learned that with other species.  I accidentally killed a "guinea pig" species (a ponytail palm that I purchased expecting my tests to kill it at some point) recently in testing.  I'm trying to determine to what degree I can boost outdoor plant survival with root heating, and made a test box, heated with christmas lights (ordered a thermostat heat mat, but it won't get here for weeks).  Everything was going amazingly well in some very cold and windy weather (worse than it should have been able to take), until I made a mistake - turned the lights from "blink" to "full" (aka, more heat), and watered.  The next day all the leaves were withered, and the subject is probably dead.  A temperature probe (okay, a meat thermometer  ;)  ) showed the temperature ~5cm down was about 13°C, meaning it was probably 20-30°C at the bottom.  This confirms what I heard from someone who ran a related experiment elsewhere: excessive soil heat and water trigger a plant to break dormancy when it's not safe to.  Even evergreen plants go dormant in cold weather.

Too bad there's not enough winter left to do followup cold-phase experiments until next year. But at least I still have the summer phase experiments to look forward to (going to see if I can get a tomato to grow outside here by boosting the soil temperature to its desired range)
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TheWaterbug

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Re: Are pineapples really this heavy feeders?
« Reply #20 on: September 25, 2018, 04:09:47 PM »
Having two in a pot doubles your root mass too.


Ah, I just noticed your comment, 6 months after you posted it!


The center is the mother plant from which I harvested a fruit a couple of months prior. You can see the remains of the peduncle, dying away in the center. That entire plant will eventually die away if I don't prune it away first.


To the right is a ground sucker that I let grow.


So it's really only one plant, even though it looks like two at present.


I have another harvested plant that I need to prune this weekend or next, and I'll try to remember to take some photos of the root system.
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