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Author Topic: in search of rootstock for tropical papaya.  (Read 724 times)

JoeReal

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in search of rootstock for tropical papaya.
« on: May 29, 2019, 11:24:13 AM »
Tropical Papayas die out every winter here when planted on their own roots. The root simply rots away even if you cover the base to keep out the cold winter rains.  So far, Babacos can tolerate the winter conditions, also Oak Leaf Papayas but I needed to add more. The only way to get new candidates is to grow them from seeds. Whatever will survive our winters in ground would be candidates for grafting the tropical Carica papaya over. 

So another experiment has begun on my quest of finding a cold hardy papaya rootstock in my backyard. To increase germination, soak the seeds in 10% KNO3 solution by weight for at least 30 minutes.  Wish me luck!

Here are the papaya rootstock candidates that hopefully would germinate using the KNO3 trick popularized by University of Hawaii.











starch

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Re: in search of rootstock for tropical papaya.
« Reply #1 on: May 29, 2019, 11:38:23 AM »
I have heard that Carica lanceolata is a little more cold hardy. The germination rate is very low (5-10% based on my experience) but I did not try the KNO3 trick. I have two seedlings that are about a foot tall now but I am sure the growth will pick up with the summer heat kicking in.

Some papayas make it though our 9b winters fine (I have 2x 15+ ft tall Tainung #2 and a 6 ft tall Solo) that have been thriving in my yard for a few years. I have fruited Tainung #2 (lots of fruits from both plants). Solo has not fruited yet. I was able to keep TR Hovey alive for almost two years, but it succumbed this last winter which was the worst one in many years for us. However, the fruit is pretty crappy so I am not bothering to replace it. Red Lady, Dwarf Vietnamese and Red Maradol have all been losers for me. Not been able to get them through a full year.

So I gave the C. lanceolata a shot. Fruit is supposed to be variegated, which would be a cool bonus :)
- Mark

JoeReal

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Re: in search of rootstock for tropical papaya.
« Reply #2 on: May 29, 2019, 11:46:15 AM »
I have heard that Carica lanceolata is a little more cold hardy. The germination rate is very low (5-10% based on my experience) but I did not try the KNO3 trick. I have two seedlings that are about a foot tall now but I am sure the growth will pick up with the summer heat kicking in.

Some papayas make it though our 9b winters fine (I have 2x 15+ ft tall Tainung #2 and a 6 ft tall Solo) that have been thriving in my yard for a few years. I have fruited Tainung #2 (lots of fruits from both plants). Solo has not fruited yet. I was able to keep TR Hovey alive for almost two years, but it succumbed this last winter which was the worst one in many years for us. However, the fruit is pretty crappy so I am not bothering to replace it. Red Lady, Dwarf Vietnamese and Red Maradol have all been losers for me. Not been able to get them through a full year.

So I gave the C. lanceolata a shot. Fruit is supposed to be variegated, which would be a cool bonus :)

It's the root rot that gets the Tropical papayas eventually especially the cold winter rains which was terrible last season, but good for California's thirsty agriculture. So grafting them to the ones that can take on the wet winters is my approach.

Trade Winds ran out of C. lanceolata and it was on my wish list. Maybe I can exchange it with something for you? If you can spare a cutting or maybe seeds in the future. I can easily propagate them via cuttings. I have many babacos propagated via cuttings and they now have flower buds. Some of them will be grafted with Brazilian Tropical Papaya this year.

zephian

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Re: in search of rootstock for tropical papaya.
« Reply #3 on: May 29, 2019, 11:51:08 AM »
I'm growing Sunrise, Sunset, Waimanalo from seed currently. They're only about 2 inches tall at the moment. Good to know about root rot, I'll keep an eye out. Anything 'tropical' in my yard is being planted in mounds. I plan on putting these between my avocados and keeping some in pots.
-Kris

starch

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Re: in search of rootstock for tropical papaya.
« Reply #4 on: May 29, 2019, 11:52:46 AM »
Joe,

No problem. I will be happy to share some cuttings with you. It will probably be next year. I want to let them get established this year.

Here they are right now (about 1 ft tall).



Here is the trunk. Has a very cool striated bark (very un-papaya-like) with this funny bulbous bottom


- Mark

JoeReal

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Re: in search of rootstock for tropical papaya.
« Reply #5 on: May 29, 2019, 12:11:23 PM »
thanks Mark!

JoeReal

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Re: in search of rootstock for tropical papaya.
« Reply #6 on: May 29, 2019, 12:21:44 PM »
Joe,

No problem. I will be happy to share some cuttings with you. It will probably be next year. I want to let them get established this year.

Here they are right now (about 1 ft tall).



Here is the trunk. Has a very cool striated bark (very un-papaya-like) with this funny bulbous bottom



I have tried this method on my babaco and tropical papaya and it truly works.  The problem with my tropical papaya though is they die at the hint of frosts coming when they're planted inground and propagated by air layering. Air layering has an excellent dwarfing effect though.

https://youtu.be/-rP8DjLC-qk
« Last Edit: May 30, 2019, 10:44:42 AM by JoeReal »

JoeReal

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Brazilian Papaya grafted!
« Reply #7 on: May 30, 2019, 12:23:14 PM »
And so it came to pass. My inground babaco has started pushing out leaves, and I bought me a Brazilian Papaya from Lowe's. Yesterday, I grafted the Brazilian Papaya to two branches of Babaco. I find it hard to cover the papaya scion with paraffin so I used a whole sandwich bag with one corner nipped to allow a little air and vapor movement so as not to cook the scionwood. Here they are and wish me luck!

The Brazilian Papaya prepared a couple of days ago by cutting back the leaves and to make the buds plumpier. It is now ready for cutting.



their destination, my captive volunteer, the Babaco papaya


First graft, wrapped in sandwich bag with double zipper for better grip. take a closer look, one corner of the bag is nipped to prevent extreme greenhouse effect so it doesn't cook my graft.


Two grafts showing... two branches of babaco grafted... each wrapped in sandwich bag.



The remaining Brazilian Papaya. It will regrow and hoping for more branches to use the next time.

« Last Edit: May 30, 2019, 12:24:49 PM by JoeReal »

starch

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Re: in search of rootstock for tropical papaya.
« Reply #8 on: May 30, 2019, 01:38:17 PM »
That is awesome, congrats!
- Mark

JoeReal

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Re: in search of rootstock for tropical papaya.
« Reply #9 on: May 30, 2019, 01:41:49 PM »
That is awesome, congrats!

Thanks Mark! Can you spare me some Tainung #2 seeds when you have them? I can't find Tainung anywhere.

Anyway, I bought a Broadleaf Papaya from Wellsprings... didn't know it doesn't like the afternoon sun unlike the Brazilian and Mexican papayas. I will protect it against afternoon sun. I was wondering if the Broadleaf papaya is the same as Tainung...


starch

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Re: in search of rootstock for tropical papaya.
« Reply #10 on: May 30, 2019, 04:20:21 PM »
That is awesome, congrats!

Thanks Mark! Can you spare me some Tainung #2 seeds when you have them? I can't find Tainung anywhere.

Anyway, I bought a Broadleaf Papaya from Wellsprings... didn't know it doesn't like the afternoon sun unlike the Brazilian and Mexican papayas. I will protect it against afternoon sun. I was wondering if the Broadleaf papaya is the same as Tainung...

Actually my Tainungs don't produce seeds. They are female only (not hermaphrodites) and I don't have any male papayas in the yard, so no seeds. However I might have a few seeds leftover from AlohaSeed. I will check my seed drawer.

I don't think broadleaf is the same as Tainung #2. I had two broadleaf plants that didn't really like our summer and died in the winter. Tainung #2 on the other hand has a different leaf shape and takes *FULL* AZ summer sun (120+ F ).
- Mark

JoeReal

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Re: in search of rootstock for tropical papaya.
« Reply #11 on: June 24, 2019, 03:33:30 PM »
Thanks to @starch Mark for sending me 6 different kinds of papaya seeds that he sealed and kept so well.  I was amazed at the result of the KNO3 treatment that I think I got nearly 100% germination on all of them, so will have to thin out the germinated seeds. Had I known that it worked so well, i would have just used 2-3 seeds per cup!

Anyway here's my results:

The plain water has zero germination after two weeks. And here's the 0.5% 24 hour soaking and 10% KNO3 30 minutes soaking results:

0pp3 by Joe Real, on Flickr


0pp1 by Joe Real, on Flickr


Papaya seeds float, especially if old and dry. Place the seeds in a bowl, place a folded paper towel over the seeds, then pour the solution over the paper towel. This way, the paper towel when wet will weigh the seeds down and will soak the dry seeds all around for the time required. Make sure to sow immediately after soaking, then water like you would like normal seeds.
 

starch

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Re: in search of rootstock for tropical papaya.
« Reply #12 on: June 24, 2019, 03:40:00 PM »
Awesome Joe, congrats on such great success rate with these!
- Mark

jlegdorf

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Re: in search of rootstock for tropical papaya.
« Reply #13 on: October 24, 2019, 09:17:41 PM »
Here they are right now (about 1 ft tall).

Here is the trunk. Has a very cool striated bark (very un-papaya-like) with this funny bulbous bottom

How do these look after a good growing season?

starch

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Re: in search of rootstock for tropical papaya.
« Reply #14 on: October 24, 2019, 11:06:03 PM »
Here they are right now (about 1 ft tall).

Here is the trunk. Has a very cool striated bark (very un-papaya-like) with this funny bulbous bottom

How do these look after a good growing season?

Dead :( This was probably are most brutal summer. Super hot (as usual, 115-120 F in July) but almost no monsoon rains at all this summer. Usually we get a little rain relief in July which increases the humidity and helps things get through. Not this year. I lost a bunch of stuff that was not established, even with sun protection
- Mark

 

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