Author Topic: Sweet Potato flowering triggers  (Read 236 times)

whwoz

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Sweet Potato flowering triggers
« on: 2020-02-15, 04:24:55 AM »
Just wondering if anyone here knows what triggers SP to flower.  Last time I checked the flower buds on the 2 plants that had them here had not progressed any further in development nor have I seen extra buds

reed

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Re: Sweet Potato flowering triggers
« Reply #1 on: 2020-02-15, 08:43:09 AM »
Just wondering if anyone here knows what triggers SP to flower.  Last time I checked the flower buds on the 2 plants that had them here had not progressed any further in development nor have I seen extra buds
Don't know how helpful this will be cause I really have little clue on what triggers flowering. I've read some that speculate or even say they are day length sensitive but that is not the case at all in my garden. I have seen some that don't flower till late in the season but I have others that flower immediately on plating out or even before. I've had sprouted seedlings bloom after their first set of true leaves. I'v had window sill houseplants bloom pretty much all winter and when they stopped I think it was because of the cold draft rather than day length.

I've never planted tubers (actually roots) to start the next years crop because of advice in Ashworth's "Seed to Seed" that indicates it might perpetuate disease so I don't know how that might effect things. Also a single root can make lots of slips and I would guess planting the root itself might end up with a overcrowded mess, none of which would end up producing well.

Comparing a new seed sprouted plant to a slip cloned plant I see little difference in timing of flowers, assuming the new sprout does flower, which most do, especially in successive generations of seed grown. Two or three generations in they all (increasingly) flower, all those I started with flowered at least some on their own. They don't all make seeds though, but that's a different issue.

Trellising certainly makes the seeds easier to find and collect as does trimming off a lot of larger leaves but I it doesn't induce flowers that I've seen. One paper said it increases pollination because the bees find the flowers easier but my bees are very determined and seem to find the flowers anyway. I'm the one that has trouble finding the seeds if the vines are all jumbled up on the ground, the bees don't care.

Weather doesn't seem to effect flowering in a plant that wants to. BUT, it does drastically effect successful flowering. Cool on it's own isn't so bad, they still bloom and set seeds down to night time of 10 C or even lower as long as days are sunny and dry. Cloudy and damp though aborts flowers everywhere from bud stage to nearly mature seed stage. That can happen even if temps are much warmer.

I haven't read much about actually inducing flowers on uncooperative varieties except by grafting but I think I have some links I'll try to find and post that do talk about it. Almost forgot, in my own experience, I left a root in the stream part of my garden pond one time of the variety Beauregard. Beauregard occasionally blooms a little for me but that plant grew giant and bloomed like crazy. Interestingly it did not make any storage roots at all. It also made no seeds but that is probably for lack of a compatible partner. Anyway maybe hydroponic growing might be worth investigation.  Another thing  I thought of is maybe not letting them grow storage roots, dig them up very couple weeks, pluck off the storage roots and stick em back in the ground.

Another paper said a big reason many don't flower at least in the US is because early breeding was so focused on a particular type of root. Breeders forced flowering and once they found varieties they liked they were cloned from then on but flowering is genetic and like everything else with sweet potatoes highly variable. The poor flowering traits got locked into the new strains but nobody cared because they were cloned from then on. That paper goes on to say the best way to fix that is genetic. Breed those that flower to those that flower and that, quite by accident is what I'v lucked into doing.

But that don't help if you don't have access to flowering varieties. So you might have no choice but to force flowers however you do it. 

I don't doubt the research I've read that says forcing flowers will perpetuate non flowering genetics, generally. From what I'v seen though they are extremely variable for everything else, so variable that phenotpyes dramatically different from the parents show up in even in the G1 and even more so after that.

For example I have had solid purple roots show up from white and orange root parents. So I speculate the genes for purple were sleeping in there some where and I bet the genes for flowering are also still in there too, ya just go to wake them up. 



« Last Edit: 2020-02-15, 09:38:11 AM by reed »

whwoz

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Re: Sweet Potato flowering triggers
« Reply #2 on: 2020-02-15, 04:24:13 PM »
Thanks Reed, 

Those comments are useful and yet...  Humid and cloudy describes our summer post fires with over 200 mm in the gauge so far.  This may well be why I have not had flowers develope fully.  Just checked the Kang Kong that flowered well last year and it is not showing bud development at all.  If we a decent run of sunny days, I should have flowers on the green leafed Japanese SP, plenty of buds on it a quick check has revealed.

Chris Morrison

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Re: Sweet Potato flowering triggers
« Reply #3 on: 2020-02-15, 04:47:52 PM »
I can't really help either, but would suggest water stress was possibly what led to my native NZ 'Owairaka Red' throwing a few flowers, which I have now carried thru, and believe is a mutation, as they are flowering and setting seed this year. The pic is a cutting of Okinawan, placed in a glass of water to root, in Oct, and it flowered! Had not seen Okinawan flower, to that point

nathanp

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Re: Sweet Potato flowering triggers
« Reply #4 on: 2020-02-21, 06:07:36 PM »
I just posted this video in another post as well.  At about 30 minutes he discussed grafting onto Brazilian Morning Glory rootstock to increase flowering.

https://www.youtube.com/watch?v=cdzh0GTSJU0

Steve1

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Re: Sweet Potato flowering triggers
« Reply #5 on: 2020-02-27, 03:30:50 AM »
I just posted this video in another post as well.  At about 30 minutes he discussed grafting onto Brazilian Morning Glory rootstock to increase flowering.

https://www.youtube.com/watch?v=cdzh0GTSJU0

Thanks Nathan. Fon42 on the Australian SP thread has been grafting to I.carnea this year as a test run for a full scaled effort next year. I think the Japanese papers i've been reading use I. nil. One trick is to make sure there are leaves below the graft for hormone production I believe.

 

whwoz

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Re: Sweet Potato flowering triggers
« Reply #6 on: 2020-03-21, 07:03:33 PM »
Will post this link here, which would be the one that originally gave me the idea to try elevating plants in hope of flowering.  May work with some cultivars, but not others.

https://www.lsuagcenter.com/portals/communications/publications/agmag/archive/2009/spring/breeding-highyielding-delicious-sweet-potatoes