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Chill-sensitive fruit truits and chlorosis

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Amanda starts with ...
I have been studying the effects of overnight temperatures less than 10C followed by warm sunny days and subsequent chlorosis on some species of our subtropical plants here. I haven't lived this far south in Australia before so it's a new issue for me.
I am wondering if others have noted similar and what, if anything, you have tried?
They re-green when the weather starts to warm in Spring - but I feel this chlorosis sets back the young trees in winter? I am guessing there is not much I can do about it - but you never know...
(This is not about frost/freezing sensitivity - only chilling sensitivity and the "e;e;winter yellows"e;e; that some plants get)

Somme of these plants have very little information - if any - in this regard - so it might be interesting to know more about them?

I will start with the regular black grumichama (Eugenia brasiliensis) that we have here, for eg.

It's 10yrs old and was relocated with us - from 700km north, where it had no winter chlorosis (much warmer nights up there)
In the warmer months here it's green - but when the overnight temps start to drop, like now, to 2-8C, followed by warm sunny and clear days (20-25C) it starts to go chlorotic...

The really interesting thing about this is that it's *only* on the northern sunward side...
It's still green on the shady southern side.
And this is why I know that this is not a cold-soil issue (and the soil is still warm in Autumn anyway)

Another plant that shows this quite remarkably is the Peanut Butter fruit tree also (Bunchosia) and I hope do do an experiment on them shortly - and will post results.

Some scientific references for those interested, below...

And the photos of the sunny/northern side versus the shady/southern side of our grumichama - in winter...showing the chlorosis.

https://www.researchgate.net/profile/Pavelas_Duchovskis/publication/259867890_Chilling_injury_in_chilling-sensitive_plants_A_review/links/00b7d52e49b5442b34000000/Chilling-injury-in-chilling-sensitive-plants-A-review.pdf

http://www.publish.csiro.au/cp/AR99076

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Amanda
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11th May 2019 11:02am
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Original Post was last edited: 11th May 2019 9:18pm
Amanda says...
Sorry - pics did not get re-posted when I corrected some info and resubmitted..
Here are the pics again
Shady side versus sunny side..
Pictures - Click to enlarge

Picture: 1

Picture: 2
 
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Markmelb says...
Miracle Fruit gets chlorosis if soil isnt acidic enough - could be similar for citrus?
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12th May 2019 10:40am
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jakfruit etiquette says...
Hi, have you considered that the plants inactivity protects it somewhat from cold and frost injury. Frost can be much worse in spring if it hits active new growth of the spring flush.
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David01 says...
Hi Amanda,
Chlorosis occurs due to many factors such as lack iron, zinc, Alkaline soil, Nutrient imbalance and winter effect on tropical/subtropical plants. In your case may be the last one, when the temp drops to below 10C it will limit MICROBIAL ACTIVITY to convert the organic nutrients needed to the plant. Microbes need porous soil and certain temp to thrive. For leaves in the shade as no light for photosynthesis working, thus stay green as indoor plant as that part not active and does not need much nutrients. However, leaf analysis will tell the true story. Cheers
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Original Post was last edited: 13th May 2019 9:33am
Amanda says...
Yea Jackfruit etiquette - this can be true in that the plants will dismantle the chlorophyll molecules in order to protect themselves, basically.
I believe this is happening somewhat - as a piece of tape put across a leaf and then peeled off several weeks later - will show *green* under the tape - but chlorotic where exposed to the sun.
Really interesting I think! And hence why they are green on the shady south side - and chlorotic on the sunny north side (as the winter sun is low in the northern sky then, here in our lower latitudes, of course)

I just want to gather the "e;intelligence"e; on these more rare plants - so that we can build on our knowledge about growing them in cooler climates.

Yes that is also possible David01 - but then that would apply for all of our evergreen trees.
That wouldn't explain, for eg: why the Kohola Longan seedling tree becomes chlorotic in winter - but the Chompoo marcot tree does not - even though they are planted 3m apart, treated the same etc.
I suspect that the Kohola is chill sensitive, therefore..this might mean that folks in cooler climates are better off planting Chompoo, for eg.

This is not a soil issue per se/strictly. Sure there are different things going on in winter, compared to summer - but it's not the problem as such.

That part - what is happening in the soil - is very complex and might be a much for this forum perhaps (don't want to scare folks off..I just want to collect the data/info)
For eg: our coastal sands are highly aerobic and thus oxidative soils.
They are also warmer than say yours...for eg. This also affects their redox potential and redox and pH are linked. So I understand all that part. I have been researching this for several years now..and have come to realise that we still have so much to learn! Even the difference between my irrigation season (with the limey bore water) compared to the "e;clean"e; rain water in winter - changes my soil chemsitry...sigh!
You might find these links interesting though - the lychee one a difference scenario - but along similar lines.

http://www.tropentag.de/2007/abstracts/full/311.pdf

http://www.publish.csiro.au/cp/AR99076
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Amanda says...
Markmelb - yes it could be why some citrus get the winter yellows - but you would need to shade a part of the tree or a branch - to be sure. It's about photo-oxidative stress and chlorophyll bleaching.
In winter where the soils get cold the chlorosis can be due to pH certainly - as the bacteria that reduce sulphur for eg - become very inactive. That's why some growers use iron sulphate in winter instead (as I do here - which overcomes that particular chlorosis problem) Wet soggy soils also change the soil chemistry - reducing oxygen in the soil (which can lead to iron chlorosis, for eg)
(I am not a big fan of iron sulphate as it's a powerful reductant...hence why I want to acidify our bore water in the long term - using a dosing pump and sulphuric acid)
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Amanda says...
This our marcotted Chompoo longan compared to our seedling Kohala for another eg? ...they are only 3m apart - the Kohala is 10yrs old and 5m tall - and it starts going chlorotic at this time of the year, every year.
The Chompoo is only 3yrs in and about 1.5m tall - it doesn't go chlorotic over winter.
We are having quite cold nights now (althoughby cold nights I mean from about 3am onwards...) and clear, dry and sunny days.
Pictures - Click to enlarge

Picture: 1

Picture: 2
 
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Original Post was last edited: 14th May 2019 7:47pm
David01 says...
Hi Amanda,

You may be interested in the link below. Cheers

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC157800/pdf/1100997.pdf
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Original Post was last edited: 15th May 2019 9:15am
Amanda says...
Yea that's kind of along the lines of what I am banging on about David01- but I am interested in woody plants here...(fruiting ones of course! :) ) as well - they have the ability to cold acclimate.
Anyway too much science-y stuff scares regular people off a topic, I have often found :/
I am still really interested in anyone else's experiences of the "e;winter yellows"e; in sub tropical fruit trees, out there?
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David01 says...
"e;Concentration of chlorophyll remained more or less constant in shaded parts of trees in winter, whereas in light exposed parts during this period, the chlorophyll concentration markedly declined and severe"e;

This link will explain why the leaves still green on the shady part. Cheers

https://www.sciencedirect.com/science/article/pii/S0176161711820687
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Original Post was last edited: 15th May 2019 2:48pm
Amanda says...
If only it were that simple David01 - I would be able to spray some zinc-chelate around and be done with it. But certainly, zinc deficient leaves are more photosensitive - but other research has turned has turned up Magnesium and/or Boron deficiency.
Then you have factor in each species...and even in between the different varieties and races (like with mangoes)
There is no one universal answer. To know this topic inside and out you need be a Professor of Plant Physiology - honestly! I won't pretend to have all the answers that's for cetain - but we can often find solutions to problems that we don't yet understand - and that is what I am looking for here.

It's actually a really interesting topic though, for people who just love learning about plants. We are quite lucky to have just one of those Professors nearby, over here...who has taught us alot about delayed greening in our native plants - and anthocyanin production (eg: new leaves that are red) as photoprotective mechanisms.
And those adaptations are also seen in tropical/sub tropical species - because the light intensity is so strong, of course, near the equator.
It's also very strong over here in WA too though - because it's much drier and therefore clearer ( = heaps less cloud cover)
But the plants don't get the chilling overnight like they do outside of their native zones 'up there'...so they are mostly not adapted to the situation (eg: google 'stomatal conductance and chilling sensitivity)

There are also some definite genetic reason why some tropcial species will never tolerate my climate in the next few generations for eg...it will a very, very long time before purple mangosteen will ever be grown in Perth, outside and in the ground.


In the meantime - I am trying to focus on other people's experiences of this problem, and if they have tried anything to alleviate it.

For eg: there are some foliar sprays that can be applied to assist with drought protection and/or frost resitance - perhaps others have tried foliar sprays of plant "e;e;sunblock"e;e; to get their plants through the cold-acclimation/hardening off process...
Maybe others feed their trees certain nutrients when that cold night/sunny day time period exists.
Others might have tried light shade cloth...
etc....

That kind of 'stuff' ...

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Original Post was last edited: 16th May 2019 11:54pm
David01 says...
Hi Amanda,

Please read my previous comment again. "e;This link will explain why the leaves still green on the shady part”
As I found the other findings in the report i.e. Zinc deficient does not apply to your case.
You will be disappointed if there is a Professor of Plant Physiology lived nearby as they mainly focus on narrow topics for research or thesis thus their findings usually not helping us to solve our common gardening problems. Cheers
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Original Post was last edited: 17th May 2019 3:39pm
Amanda says...
I found the whole paper David01...it's very interesting thanks...it even has this picture in it...which is what I have observed also.
Also interesting about the accumulation of iron in the leaves when they are zinc deficient too.

And Zinc Efficiency and Inefficiency are genetically based....I wonder if the Kohala longan is an *in*efficient type and the Chompoo is an efficient type. Hmnnn!
Maybe that is getting ahead of things though...

https://nph.onlinelibrary.wiley.com/doi/pdf/10.1046/j.1469-8137.2000.00630.x
Pictures - Click to enlarge

Picture: 1
  
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Original Post was last edited: 17th May 2019 10:36pm
Amanda says...
I also found several references to increased bicarbonate concentrations inhibiting Zn uptake (which could be an issue here due the carbonates in the bore water, for eg) and maybe others have had similar symptoms with their water (or soils that are 'limey'/calcareous)
This reference also comments that 'Mycorrhizal plants usually have higher zinc contents in the shoot dry matter and are less sensitive to zinc deficiency than non-mycorrhizal plants'
Bicarbonate is a real PITA.
Two of the Professors here have actually been very generous and helpful for me btw David01 - as they work in the area - one academically and the other commercially. Lucky for me - but not for them perhaps...I ask lots of questions!

The problem with bicarbonates/calcium carbonate in bore water is not uncommon on the coast here - and studies his PhD students have done on chlorotic native Jarrah trees being watered with this water have shown decreased leaf manganese levels compared to non-irrigated trees.
(But this had nothing to do with overnight chill and sunny days of course. Just an example of a problem caused by poor quality irrigation water - which will likely become a bigger issue as we slowly dry up and the ground water becomes more affected)

I think it's fascinating, but also very complex....I feel like I might have a kind of 'perfect storm' of events happening here perhaps: the limey bore water, the light soil, chill sensitive species, our Autumn weather - and then 3-4months of soaking rains over winter (but which counteract the bicarbonate at least)

I am hoping that when we install a dosing pump for sulphuric acid that it will smooth out many of these issues.

These are the results for our bore water - just to add them to thread for posterity (and also because I know that some folks tap/scheme water has higher levels of calcium carbonate - on our coast zt least - and may be struggling with similar issues)

https://link.springer.com/chapter/10.1007/978-94-011-0878-2_5

Pictures - Click to enlarge

Picture: 1
  
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Original Post was last edited: 20th May 2019 8:03pm
David01 says...
Hi Amanda,
If high bicarbonate inhibit Zn uptake then in that case Chlorosis should happen at any time (permanent), but not waiting until temp drops below 10C for tropical/subtropical plants (temporary). My opinion for Chlorosis is as below:
1. If Chlorosis occurs during ideal climate then the plant may have issue with incorrect fertilizer, incorrect PH level, lack of trace elements, poor soils or water etc . Then Chlorosis issue can be corrected accordingly by followed recommendation from experts. However, in practice it is not easy to find the cause or correct solution unless obtained leaf test results or after many trials
2. If Chlorosis occurs due to temp drops below limit during winter, plant tissue could be damaged and solution 1 will not fix problem immediately as plant needs to wait until next growth season to repair the damage tissues by itself and solution 1 may be applied to speed up tissue repair but not before then. And of course unhealthy plants (due to 1) will be more vulrenable to cold weather. Cheers.
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Original Post was last edited: 25th May 2019 9:00pm
jakfruit etiquette says...
I did have a look at this stuff re potting mixes and nutrient interractions.
It became too complex for me, especially trying to follow individual elements like Fe vs Mg vs P etc etc.
I did find that experementing too much can lead to mistakes.
Also mulch, microbe activity, foliar sprays, pH, composted fertilisers, humates, humic+fulvic and rock dusts, zeolites and forms of chelates can overcome some of these problems without trying to make total changes. Plant feeder roots can often be found moving into leaf litter layers, where the nutrient forms are different to whats in the soil. You can try to mimic this, as is the case with most tropical soils where most nutrients are only in the very top layer.
Rain, humidity, night time temperature and daylength can be as or more important as day temperature for sub tropicals and tropicals to grow outside of normal areas.
Some plants seem to wake up at certain times of year, not just due to day temps alone.
Citrus are interesting, being subtropicals but also grafted onto cold hardy rootstocks or in many cases rootstocks better suited to specific soil types. Avocados also have some choice re rootstocks for cold or soils/salt.
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Original Post was last edited: 26th May 2019 11:23am
Amanda says...
Yea David01 - that is a good point - and oddly enough I was just thinking about how they are fine in the warmer weather and how can't I even tell that the leaves might be on the low Zn side anyway (without an expensive leaf analysis) when they are not showing any deficiency at all....so annoying -because I also agree with JFEtiquette - there can be so many knock-on effects from adding the wrong things and/or at the wrong time...been there, done that too...
It's a bit of a rabbit hole isn't it? I can get my head around a bit of the individual chem ok but once the temperature and water changes kick in as well, then it starts to do my head in.
Have to be careful not to 'over think' it also.
I am going to go with adding a little zinc sulphate in Autumn though - just to see what happens....if anything.


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Original Post was last edited: 27th May 2019 10:47pm
Amanda says...
ps David01....back to the topic of Zinc Efficient plants versus Zinc INefficient plants (cos' it's really interesting!?) I found this reference - but it's the map/Fig 1 that I find worth a peek - because many of these plants we are trying to grow come from areas that are generally not Zn deficient (not severe or moderately so anyway (unlike where I am)
We tend to forget the genetic aspect to these traits - or more likely we actually don't know about them yet...

"e;e;As a consequence of coping with low Zn availability, certain
plant genotypes are able to grow and yield well under Zn
deficiency, which has been termed Zn efficiency (ZE)
(Graham & Rengel, 1993). ZE is genetically based and the
physiological and molecular mechanisms underlying ZE are
just beginning to be understood"e;e;

This is partly why I posted this thread - because maybe we can work out if there is a genetic problem by our experiences growing some species in cooler climates?

I have my definite "e;e;suspects"e;e; and they are Jaboticaba, peanut butter fruit, malabar chestnut, for eg...
I have a another few I think are "e;e;maybe's"e;e;
But it's harder for me to tease this out because of my alkalinity issues...?

Funnily enough I found a reference on this forum from 10years ago - where I had already pegged Zn and sunny side chlorosis? lol...
Swiss cheese brain...
But at least Recher confirms a similar issue with jaboticaba...

(only a few posts down)
https://www.daleysfruit.com.au/forum/jaboticaba4/


https://nph.onlinelibrary.wiley.com/doi/pdf/10.1046/j.1469-8137.2003.00826.x
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Original Post was last edited: 27th May 2019 11:21pm
David01 says...
Hi Amanda,

Are you Amanda19 10years ago? Welcome back.

Many studies tried to work out solutions to improve plants with zinc deficiency and plants growth in soils with low level of zinc, and some of them are adding Zinc, cut back high phosphorus fertilizer and secretion of root exudates, as various types of root cells sense microbes or compounds in the soil etc. However, I think these findings only work in the ideal climate. As I already tried to spray Zinc and iron Chelates on leaves and improved microbes in soils on Pumelo and other tropical fruit trees in winter when all young leaves get chlorosis but result was not better. However, when the weather improved, all the leaves back to normal in Dec instead of Sept. The reason took that long as plants need time to wake up and time to repair damaged tissues. By dig in too much in research documents sometimes make us confused and can lead to mistakes as jakfruit etiquette comments. For example, for chlorosis issue, one document says lack of Iron, others say Zinc, then PH, then soil, microbes, water etc. etc. you can find more than hundred suggest solutions for one simple chlorosis but only few solutions can be applied to correct the problem if and only if diagnosis is correct and this is the most important but tricky part and most of us fail to do so as lack of resources or experiences. Cheers
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Original Post was last edited: 28th May 2019 7:21pm
Amanda says...
Thanks so much David...and you are the first person I have finally encountered who seems to understand what I am on about here hey?
Wasn't sure about you at first - so I am sorry if I was a bit short.
(yes the same Amanda from back then. The new security measures on this page have made it nice to be able to pop back in again :) )

I will get back to you about what you have said there - I am also putting my feelers out to try and get some more knowledge (three professors - lol)

It's a controversial thing to say I know - but CRISPR will likely be the solution - it will be a case of just popping that zinc-efficiency gene in....shhh! ;-)



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Original Post was last edited: 30th May 2019 12:56am
Amanda says...
David01 - do you get the chill-chlorosis on plants in your greenhouse as well?
Is your greenhouse heated?

I have had problems getting my fertilising regime sorted out here - as it wasn't until I got the bore water tested that I realised where the problem was.
Now I think I have it under control - so it's interested to see that - so far - the peanut butter fruit trees are not going chlorotic....even though we have had very cold nights and bright warm sunny days - and really dry weather...perfect conditions for that sunny-side chlorosis to happen.

(the bananas are starting to go though)

Anyway - I will see what they look like at the end of winter....but I was thinking that maybe they do better/stay greener when then they head into winter with a full 'larder' of zinc (and/or Mn, Fe) - especially given that Zn mobility in the plant is also linked to it's levels (ie when it's low then it doesn't get translocated to the new growth...)

But it could also be because the plants are much bigger and thus have a more established root system - or that I have been acidifying the soil over summer - and this has made the zinc more available at the criticla times of growth?

I can't say that I have ever had much luck with chelate sprays either to be honest - so it's interesting you have mentioned that also.
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David01 says...
Hi Amanda,

I have more than 30 tropical fruit trees in the green house. No heater installed during the first year thus min temp 5C for 3 months from June- August. Chlorosis occurred to 30% of all tropical fruit trees. In the second year, 2 heaters were installed to control min temp around 10C. Still have chlorosis occurred on Pumelo Namroi and Abiu despite applied trace elements and soil treatment. Last year min temp was increased to 15C and result is better as only Namroi has minor Chlorosis.
Based on the experiments my conclusion as below:
Temperate fruit trees go dormancy in winter to protect itself by slow down everything such as drop leaves, heal cuts or wound etc. So they need very little nutrients uptake to stay alive thus don't have much issues.
While tropical fruit trees growth in non ideal environment, they have no mechanism for going dormant to protect itself as temperate plants. The root systems of tropical fruit trees below 15C will stop growth and not functioning or deteriorate, plants need nutrients uptake but roots can't provide as required. As a result, chlorosis and other issues could happen etc., Any attempts will not change the situation until weather improved. Although chlorosis and chill-chlorosis look identical but their treatments are not the same.
However, if your plants are big and very healthy, better root systems and well prepared during summer then of course less problem as they have more sugars stored in the roots and trunks to handle cold better in winter. Needs to check the level of salt in Bore water. Below is a list of salt tolerant in plants and human. Cheers.
http://www.borewell.com.au/resources/groundwater-salt-levels.html
https://www.dpi.nsw.gov.au/__data/assets/pdf_file/0013/164101/Farm-water-quality-and-treatment.pdf

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Original Post was last edited: 6th June 2019 8:36am
Amanda says...
Makes sense David01. And there are the sub tropicals that can be deciduous or semi deciduous in our cooler climates, like the Annonas. Our Tropic sun atemoya is buck naked by late winter and the montanas partially. The Malabar chestnut is also partially deciduous.
The leaves on these do go yellow before they drop - so perhaps leaf senescence, but due to stress (cold-induced stress) rather than ageing - and is part of the problem.
Amazingly the Jackfruit is not bothered in this way, in winter...but does get a little bit of tip die-back when it's very wet and cold.
There are so many differences between them all, aren't there.

Your experience and results with the heating is very helpful thanks.
You sure do have the fruit tree collecting bug don't you!? haha....it's very addictive.
One of the next stages, here, is to see what trees will be able to ripen any fruit in this climate.
Eg: the Tropic Sun atemoya is carrying young fruit now - it remains to be seen if they will ripen, now it's winter - or hang on until warmer weather?
I can grow Jackfruit, also - but will I ever get a ripe fruit, if any at all.
That's all part of the fun and the challenge though isn't it! :-)
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