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View Full Version : A simple but profound question!


asacomm
02-27-2011, 07:00 PM
Hi friends,

Here is a simple but profound question bananas' overwintering.
There were planted in the ground two 1 year old young plants of the same
species for completely unprotected overwintering, one under full sunshines
and ther other under limited sunshines.

Then here is a simple question:
"Which was the winner of the overwintering, under full sunshines or under limited sunshines?"

The answer for this question seems to be also simple, under full sunshines.
but the result was the oppopsite, under limited sunshines.

http://www.bananas.org/gallery/watermark.php?file=40510&size=1
This is the plant under full sunshines. The center core was dead.

http://www.bananas.org/gallery/watermark.php?file=40509&size=1
This is the plant under limited sunshines. The cigar leaf keeps green and stiill
growing.

Why the result turned out to be opposite against common sense?
I think it is deeply connected with the difference of the lowest and the highest temperature.
While the banana planted under sull sunshines was exposed by high tempe-
rature during the day time and by low temperature of some -3C early in the
morning, the other banana planted under limited sunshines could keep relatively
stable revel of temperature and so the plant did not receive so strong stress
that it died.

What do you think?

planetrj
02-28-2011, 01:15 PM
This is a very good question, but there could be so many variables to this really. It would need a closer look to know for sure.
First off, the root ball would need inspected. Possibilities could be: core temp, pests, depth of planting, dormancy moisture, fungal, remaining stored energy when frost hit, etc etc.

I think you also hit another good point, which is the flux of temps with or without protection. That makes a huge difference, and also so does direction of exposure (N,S,E,W).

Experiments like this are always great to ponder upon! :)

asacomm
02-28-2011, 06:17 PM
Many thanks for your comment, Rj,

You are right in saying that so many variable factors should be examined
and verified before deciding any conclusion.

But on the other hand, the biggest reason of my guess is that the same
thing had happened with my avocado trees.

The leaves of the same species and the same year showed exactly the
opposite result against the temperature difference between the lowest
and the highest depending on their standing locations.

The leaves of the tree planted under full sunshine died, while the other one
under limited sunshines were alive and kept green.

Bob3
02-28-2011, 06:20 PM
... there could be so many variables to this ... I sure agree with that; plus it's a pretty small sample to try to draw any conclusions from.

That being said, it's pretty well known that repeated freeze / thaw cycles can raise way more mischief than a more steady temperature range.

Kostas
03-02-2011, 04:42 AM
Thanks for sharing the photos asacomm!

Did the shaded one had anything overhead that shaded it or was it only shaded from the side? Its well known that overhead protection,be it from an overhang or from tree canopy,helps a great deal at reducing damage to cold sensitive plants by keeping the temperature a few degrees higher(trapping heat)and not allowing frost to settle on the plant underneath. So its only logical a shaded banana would have better chances to retain more of its parts alive than one grown in an exposed location,such as one receiving full sun. I tend to favor planting cold sensitive plants in shaded and overhead protected spots myself rather than planting in full sun for that exact reason! It may take them a little longer to grow but they look much better in winter and after it and for many plants,retaining their leafs over winter means they will grow much faster in warm weather,at least for a month or 2, than they would being leafless in full sun! With bananas,which have energy reserves in their corms,it may not be that big of an advantage though but it surely helps retain more pseudostem height!

P.s.:Looking at your pictures,both seem alive to me but your full sun grown one is apparently much more stressed and damaged than the other,so it will take it a little longer to start growing. The new leaf seems dead/damaged but the meristem may be alive and push a new one after some time!

asacomm
03-02-2011, 04:42 AM
Many thanks for your nice comment, Konstantinos.

I do agree with what you commented. You analized the phenomenon quite
theoretically so everyone can understand the problem.

The shaded banana plant had nothing overhead, but houses and contruction
structures shaded it naturally. So I think it could kept relatively constant
temperature levels which prevented it from death.

Kostas
03-02-2011, 05:16 AM
Then possibly proximity to the house played more of a role if nothing was overhead it directly or at least close by,which would also help some. I am not sure if a shaded but exposed to the elements spot would be better as that would mean the plant would stay cold/frozen in bad nights/days for longer than if it was somewhere the sun could warm up. I would guess that shade without overhead protection or proximity to the house,would mean more damage as the damaging tempratures would persist for longer. When canopy or house/heated structure proximity comes in play though,things are much better than an exposed sunny location!