Author Topic: Breeding Sweet Potato in Australia  (Read 2110 times)

whwoz

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Re: Breeding Sweet Potato in Australia
« Reply #105 on: 2020-03-23, 02:47:48 AM »
What is your summer weather like Chris,  ours is typically hot without any real spikes.   If the heat builds it generally does so after a cold front has gone through. Think maximum temperature dropped to 20C, it then builds up by 4 degrees each day back upto the mid 30's here, where it generally sits until the next front moves through. The really hot 40+ days are generally wind driven, with hot air being blown out of the centre over us.

Reed is your summer weather consistent or more up and down and what temperatures do you normally get to.

Another thought,  do either of you have any idea of the length of bright light (excluding twilight)  you have on a summers day

Chris Morrison

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Re: Breeding Sweet Potato in Australia
« Reply #106 on: 2020-03-23, 03:07:56 AM »
whwoz, as we are an Island, vs both you and reed have continental climates, ours varies much more, but where I am we have more sun less rainfall than the rest of NZ. It is an area renowned for its vineyards, orchards and cropping - Hawkes Bay.
I found the first 2 seed pods after a hot spell in early Jan, then we went cool, low 20's,  so no action for 3 weeks, despite good flowering.
Then boom, heat again 30+ from early Feb, and the seeding went nuts. Now cooled back down to low 20s, and much cooler nights, so I do not expect anymore seed pods (although still 100 odd on the vines drying off). Google Havelock North 4130 NZ to see our weather chart?

whwoz

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Re: Breeding Sweet Potato in Australia
« Reply #107 on: 2020-03-23, 04:11:25 AM »
Thanks Chris,  will check out your suggestion re:weather

reed

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Re: Breeding Sweet Potato in Australia
« Reply #108 on: 2020-03-24, 01:08:01 AM »
Here it can stay around 30 to 35 for two or three months but it is getting so weird. July, August are generally hottest but in 2018 we had a period with highs little over 20 and damp in August, it ruined lots of seeds. In 2017 it stayed in the 30 -35 range into November.

Just generally, warm dry is good for seeds, damp cool isn't. Mine do seem to keep setting seed even when it starts getting cooler so long as it also stays dry. I haven't measured how weather effects food production but I've never had a serious crop failure.

I expect in coming seasons some will be good for seeds and some bad, last year was very good. But in a good year you get lots and they stay viable a long time so always have that backup.

Richard Watson

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Re: Breeding Sweet Potato in Australia
« Reply #109 on: 2020-03-24, 12:31:01 PM »
I'm sure you have to have that 30Cdeg + to set seed, when eastern North Island had the Fed hot spell Chris had plenty of flowers open, the South Island the heat was only in the inland valleys like where I am, but during that heat I had yet to reach good flowering stage, the flowers came once it cooled down. The summers of the last ten years have not been as warm as the 2000's when we had much longer periods of heat.
Changeable year round climate, less so summertime, warming winters - just under 500mm average yearly rainfall. 20 years of soil improvements plus sub soil top soil reversal means my garden beds are about half metre deep. Below that is 100's of metres of alluvial out wash from the Southern
alps.

reed

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Re: Breeding Sweet Potato in Australia
« Reply #110 on: 2020-03-24, 03:16:53 PM »
You might be right but I'm not wholly convinced. Dry and sunny seem to be key rather than just heat. I have on occasion found mature seeds on plants I had discarded after harvesting the roots even after frosts. They may be source of some the volunteers I'm seeing now.  And I often seed set continuing well after cooler fall weather has arrived.

I won't say much of anything for sure though, except in my patch cloudy wet is counter to seeds, they don't set in those conditions especially if it's cool. Wet is bad even if hot, they can rot or sprout inside the capsule.

Then there are lots of other variables probably between different places and the great BIG variable of them being so variable. The term homozygous doesn't begin to describe it  I don't think.

Richard Watson

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Re: Breeding Sweet Potato in Australia
« Reply #111 on: 2020-03-25, 10:58:15 PM »
Had long period of dry and sunny weather here after early Feb but no real heat.
Changeable year round climate, less so summertime, warming winters - just under 500mm average yearly rainfall. 20 years of soil improvements plus sub soil top soil reversal means my garden beds are about half metre deep. Below that is 100's of metres of alluvial out wash from the Southern
alps.

whwoz

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Re: Breeding Sweet Potato in Australia
« Reply #112 on: 2020-03-26, 02:57:18 AM »
Here in eastern Victoria, December was hot and dry,  then came the fires, turned everything smoky, then the rain arrived in January and February.  275 mm or 11 inches. March has been considerably dry, be lucky to get 40 mm but very overcast.  Temps here have probably been 6 or 7 C below average. The bulk of what I am growing is the same clones as the last three years and I suspect that I need to radically change something to get them to flower here. As long as we don't severe a frost I think the plants on the dam, which already have roots coming out of the pots will stay over winter.  The current lot were just random selections, will set up a second pallet with labelled plants when I harvest roots to try to jump start next season.

That great variablity that Reed keeps mentioning seems to keep rearing it's head in a non helpful way at the moment

Chris Morrison

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Re: Breeding Sweet Potato in Australia
« Reply #113 on: 2020-03-26, 04:03:56 AM »
Well, back on the fertility theme, I am growing in near neutral pH, maybe 6.8, thanks to our clay pan (it is slightly sloped hill side garden)
I always look at pH rather than other indepth analysis, which can confuse and be wildly inaccurate imho.
We grow a lot of garlic, and I have learned the closer to neutral the better - maybe similar for SP flowering?
Be interested to know pH of your guys soils.

whwoz

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Re: Breeding Sweet Potato in Australia
« Reply #114 on: 2020-03-26, 05:26:46 AM »
An interesting thought Chris,  had not considered that.  I suspect that the pH of the soils I am growing in would be down around 5.5 using a standard 2:1 soil:calcium chloride solution.  Any idea what method used for your 6.8 result?  I have a powder based test kit and will check over next day or two.

Chris Morrison

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Re: Breeding Sweet Potato in Australia
« Reply #115 on: 2020-03-26, 05:54:21 AM »
It's limestone country here, P retentive, and ~ high pH generally, in the hills, different on the plains, but yes I see it in indicator plants like lettuce, and solanaceae, they do not grow well without Flours of Sulphur,,, citrus like wise, and avocado's too, struggle.. Garlic/Alliums and SP seem to enjoy the neutrality. 5.5 seems hell low to me, Blueberry country?

whwoz

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Re: Breeding Sweet Potato in Australia
« Reply #116 on: 2020-03-26, 06:09:42 AM »
5.5 not to bad for our soils,  in some regions pH can get down to 4. Likewise we have some areas that are limestone rich where soil pH can get over 8. Soil that I grow in are predominantly imported as local silt just locks up in summer,  think concrete,  in winter water table is above ground level.  The sand which I grow in is typically around the pH 5 to 6 level,  which is good for nutrient availablity across most nutrients. Drainage is good and easy to keep moisture levels up pumping from the dam

whwoz

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Re: Breeding Sweet Potato in Australia
« Reply #117 on: 2020-03-27, 02:53:10 AM »
While overseaing some prep work for what will be a 25 x 14 meter extension to the vegetable garden,  I eventually opened my eyes after walking past the SP several times and found,  not one but 4 flowers on the Beaurgard plants. While photographing the flowers for posterity,  I noticed a number of bees about.  Two honey bees flew past,  not stopping and several native bees stopped and checked it out.  One was very interested and spent a couple of minutes inside the flower,  crawling out covered in pollen!!  That bee then crawled into the next flower,  so I should find out if Beauregard is self-compatable or not.  Photos to follow

Steve1

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Re: Breeding Sweet Potato in Australia
« Reply #118 on: 2020-03-30, 07:58:06 PM »
While overseaing some prep work for what will be a 25 x 14 meter extension to the vegetable garden,  I eventually opened my eyes after walking past the SP several times and found,  not one but 4 flowers on the Beaurgard plants. While photographing the flowers for posterity,  I noticed a number of bees about.  Two honey bees flew past,  not stopping and several native bees stopped and checked it out.  One was very interested and spent a couple of minutes inside the flower,  crawling out covered in pollen!!  That bee then crawled into the next flower,  so I should find out if Beauregard is self-compatable or not.  Photos to follow

Whwoz thats good news on the Beauregard front. Is the ornamental still flowering?
I had a soil test done here last December, and the pH was 4.9. I haven't really attempted to ammend it with the exception of some mushroom compost.
I've also got one of the ornamentals flowering as a houseplant and am using pollen from the garden. I may take cuttings of the others that have multiple flowers on different stems to see if that might get me some seed set. Getting too cool outside now.



whwoz

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Re: Breeding Sweet Potato in Australia
« Reply #119 on: 2020-03-30, 09:50:36 PM »
Steve I cannot say if the ornamental is still flowering, could not see any but there is an absolute mass of leaves there.

pH of 4.9 probably a bit low, you may start seeing the effects of Iron deficiency soon, would suggest plenty of lime, if you can get crushed limestone, will help stabilize over longer term as well. 

flowers, showing the main stem with two or three clusters on it, then a close up of one cluster