louis14

I thought I would keep the forum informed of our first trials at macro propagation.
We have built two wooden boxes in 2m x 1m

and lined the bottom and sides with a sheet of black 300 micron LDPE, filled the box with 30 kgs of sawdust and positioned about 30 pared corms of Thai variety Kluai Hom (Gros Michel)




We started this 8 days ago. The sawdust is being kept nice and damp, initially given three watering cans H2O and this is the dosage we are giving every three days now. The boxes are covered with clear 150 micron PE sheet, tied down with string.
Yesterday, I checked the corms. It's nice and hot and damp in the boxes, outside afternoon temperature is 40C right now. A few had dominant buds growing which I promptly killed. Some have already developped new roots which are 5cm long and showing up on the surface of the sawdust.

We have built another two boxes now and will start the same process with Kluai Namwah as soon as the corms become available.
For both varieties, we are using large corms, about 15cm in diameter.
I'll will keep you updated on developments.

Akula

Pardon my ignorance but what is the source of the corns? Are they from pups that you dug up or are they shaved off of a donor plant? Will you divide them again once they get established in the box and put out some roots?

Thanks for sharing your technique. Very interesting. Good luck!

louis14

They are pared corms from pups we dig up in our plantation.

They are not to be divided. The dominant buds are killed and the roots are shaved when the corms are pared
If all works properly each corm should shoot up to a dozen new baby clones that will grow on the edges of the corm and that will later be detached from the corm and allowed to develop independently into fully functional banana plants.

edwmax

Does the black LDPE allow excess water to drain from the bottom of the box ? Would you show us a picture of the prepared corm?

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louis14

We did not include holes in the LDPE lining to drain excess water, there is a lot of sawdust in there, very absorbent. The watering is carefully done, I think holes would accelerate drying, I have no reason to wish to accelerate drying of the sawdust.

I'll make a photo of the next corm we prepare and post it. I am sure there are improvements to be made on that job.

MediaHound

Great project! Wishing you the best of success! Looking forward to seeing and reading more of your posts.

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louis14

Here are a load of pics of the corms taken today (12 days in the boxes)

They are looking well!

Should I continue killing any dominant buds still pushing up?

There are white roots crawling all over the sawdust!

Any informed advice is most welcome

Tomorow, we will make a box of Namwah corms, so I will take photos of the pared corms and post them here.

edwmax

Thanks for the update. ... I found his artificial article from the ECHO Community which gives in detail ( more then other references) how to prepare the corm. ... https://www.echocommunity.org/en/res...377c5/download ...

As for the water draining from the bottom of the humidity chamber, the above artificial does indicate the bottom should be well draining and the sawdust should only be damp. So be careful how much water is added to your chamber.

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louis14

Many thanks for the article, I have read it through twice. We are in line with what they recommend although they have more of a lab approach with some steps I find not so practical or useful when doing this in a large scale.
They also do not mention canceling already existing secondary buds on the corms while paring, when this is mentionned in other articles I have read.
Anyway, well noted and nice to get some confirmations
It would seems everything in proceeding nicely.

edwmax

This is interesting to me because I need to increase the numbers of a couple of my nana varieties this year. I was already making plans when you posted this thread. The procedure i had download and studied last year. ... However, I would be doing this on a smaller scale than yours using 2 or 3 corms in a nursery pot or smaller box as the humidity chamber and there would be no need of 2nd or 3rd cycles with the plantlets on my part. Just a few dozen plantlets from each corm is more than enough as i understand one corm can/may produce up to 100 plus plantlets.

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Akula

Thanks Louis14!

Very cool project! Please keep updating till you get to the end! So many times people post up a rather interesting situation, condition, or project and then they don't take the post to the end/conclusion so impossible to tell whether they were successful or not in their endeavor leaving everybody hanging.

Thanks!

louis14

The second and third cycles tech seems to be really more adapted to pure nursery work. In our case we need to fill the remaining fields in our plantation with several thousand banana plants as quickly as possible so as to double the size of our crop. If we can get even only 10 plantlets per corm it will be great. We can always make more boxes which would allow me to experiment tweaking with auxin and other compounds. What is needed is to master the technique. This does not seem too difficult to achieve in view of our local climate and the extraordinary green power of bananas.

edwmax

Sorry I missed the question. ... YES ... my understanding is a growing meristem will inhibit the growth of new shoots/suckers. Look at Fig 5; 6; & 7 of the reference i linked above. Don't murder the center grow point by smashing. I think this encourages rot to form. Cut a cross as shown by the reference all the way down through the bottom leaf ring. ... I think this will now cause each cut section to act independently as if the corm was split into; and thus causing multiple shoots to grow.

I think some sawdust over the top of the corms (3 or 4 cm) will help the new shoots to grow and to grow roots also. The mother corm is dying and will rot away in 2 or 3 months so the new shoots need to start root growth.

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louis14

Today we made a new box with Namwah corms. Here are photos of the corms being pared, as promised


Nice, healthy and freshly dug Namwah sword suckers










Killed apical meristem


Pared corms


The leftovers

Gabe15

I would recommend to put drainage holes in. As the top layer evaporates (where most of the roots are), you will water more and more, but the water will collect at the bottom layer and can get very soggy and start to rot out the corms and roots. This is easily solved by drainage holes. They will not make the sawdust dry out quickly, but will allow for more even moisture throughout the medium.

I would also recommend to do a hot water bath treatment (54°C for 20min), you can fit a lot of corms in a steel drum and do relatively large batches at a time, you can also keep reheating the water and do more batches back to back. Just put the drum over a propane burner or fire and check temperature. Since you are going through all of the work to clean and pare the corms, it would be wise to ensure against corm weevils and nematodes at the same time. The paring alone does not necessarily kill all of the nematodes or weevil eggs which can be burrowed into the corm itself.

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Tytaylor77

Awesome work Louis! I also recommend the dipping in hot water!

I take the small plantlets and re-initiate the larger/thicker ones. Even if the small ones only have 1-2 roots they will keep rooting just repot them in sawdust. I always break off any side roots I see! If they are on or close to the top I will leave them. After 3 generations of re-initiating you will have a lot of small plantlets!

As always you can contact me anytime!
Ty

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louis14

Many thanks to all for the much appreciated comments.

1/This is a plantation, we aim to make a profit, no just spend and spend. The 300 micron LDPE lining, if pierced will become unusable for any other project when it is guaranteed to last 25 years, so it would be an expensive misuse to pierce it. Much simpler for us to prod into the sawdust, without moving the corms and check humidity levels before and after watering.
I have miles and miles of irrigation pipes, that has taught me that the way to save large amounts of cash is to re-use, recycle, which requires planning and non destructive practices/uses when possible.
2/ We are 100% off the grid, so boiling water, only over a fire! Not so practical! That is why we use either bleach or KMnO4, which we used on all the corms in the first three boxes.
3/ We learn by trial and error but we are not in laboratory conditions. If all first three boxes fail in one month or two, we will revise and improve our method.

(I used to pick, weigh and count nematodes from a Kg of sand kept in formalin to evaluate biomass. It was done using a binocular microscope. Precise marine lab work it was, were it not for the fact that the samples had been dredged in a less than scientific manner).

edwmax

What you could do is lay the bottom boards of the box with a spaces about 1/2 the width of you hand and cover with newspaper or thin cardboard, old fiber sacks cut open, or hardware cloth (3 6mm). Then drape the sides with the LDPE or black polyethylene plastic (cheaper). But here if the side were boarded about 1/2 way up the box, then the plastic only needs to cover the top and partway down the side.

I also think clear plastic would be a more useful for this since the boxes are under a roof and there is no direct sunlight. I don't think you need total blackout in the box. ... But I do understand you are using materials that are on hand, so I'm not criticizing. With the clear plastic you can inspect the boxes without opening the plastic. To check the humidity, you only need to see water collecting on the plastic in the early mornings and add water if there is little or no water.

I build smaller propagation boxes for use in my greenhouse. It's the same. Some plant cuttings needed to be covered for higher humidity; some don't.

Keep the pictures and updates coming!

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edwmax

oh ... here is a thought ... use banana leaves in the bottom of the propagation box ... there is plenty on hand and the cost is nought.

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Tytaylor77

Awesome ideas Ed. He is using clear plastic on top. The black plastic is only on bottom.

Louis I know you said you had trouble finding sawdust. Can’t remember if I told you but try rice hulls if they are easier to get! I hear they work about as good. Personally I just love playing in the sawdust haha.

Great job my friend!

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