True Potato Seed Trials

[farmermike]

Finally got to try growing True Potato Seeds last summer. I got seeds from jondear and Joseph Lofthouse, and planted them in a couple big pots, because I ran out of room in the garden.

Here is what I harvested from the 2 pots. I'm really happy with the diversity here.


Got lots of new TPS (including some diploids) in trades this year that I'm really excited to try out. I can usually start planting potatoes out in February in my mild climate, so I think I will be starting some TPS soon. If I get them planted early, they can grow mostly on the winter/spring rains and I won't have to water.

I realized that, in order to grow my own TPS, I may have to grow them during the long days of summer to get them to flower. Does that sound right?

When I grow them in late winter/early spring, and harvest when they dry down in June, I never get flowers. Last summer, I grew an unknown purple potato during mid-summer (with lots of irrigation) and it flowered profusely. It still didn't set any berries though. It seemed to be producing plenty of pollen. Was it likely self-incompatible?

[jondear]

Those look nice Mike. How big of a pot were you using?

[farmermike]

Jan 31, 2018 22:10:46 GMT -5 jondear said:

Those look nice Mike. How big of a pot were you using?

They were in squat 15 gal pots, 17.5" wide at the soil level. None of the tubers got really large, but the soil probably wasn't that great -- whatever old soil was already there, with some composted manure added in.

[nathanp]

Feb 1, 2018 1:27:13 GMT -5 farmermike said:

Jan 31, 2018 22:10:46 GMT -5 jondear said:

Those look nice Mike. How big of a pot were you using?

They were in squat 15 gal pots, 17.5" wide at the soil level. None of the tubers got really large, but the soil probably wasn't that great -- whatever old soil was already there, with some composted manure added in.

In general, you will get smaller tubers when growing potatoes in containers than in the ground. When potato plants grow more tightly together in the ground they do the same things. Usually it produces a larger quantity of smaller tubers. Having TPS plants with lower yield than potatoes from tubers is normal. The percentage of TPS plants producing a 'normal' yield when compared to tuber grown plants is fairly low. You would still get some usable tubers for either eating or replanting, but it's really no comparison. Some potato lines will yield higher yielding results, and you can breed for that, but the percentages are still lower in general. Probably most are not worth regrowing from tubers. I find only about 5-7% of my TPS plants on average, produce acceptable results when grown from tubers.

I like the looks of the long, pink fingerling and the narrow russet that you have in the picture.

It is difficult to predict flowering and berry production, but cool temperatures below 80F and long days is the best combination. When temps cross 80F, berries get dropped. At 90F most varieties just quit flowering, in general. There are exceptions, but those typically have some wild species in the parentage.

I find there are many factors that impact berry production, and it varies from year to year. Available nutrients, water, soil temperatures and what variety it is all are factors. So many things that are difficult to control, if at all. Determinate varieties only really flower at one time within the first 30-45 days. Once you miss that window, you don't get another with them. Indeterminate types will usually give you several times as long as temperatures are cool enough.

If you are inclined to try hand pollinating, early mornings before it gets hot tends to be the best time when flowers are open. Similar to tomatoes.

[ferdzy]

We've been growing out a few clones for a couple of years now; a few will be going into the ground for the third time this spring. These are as far as I can tell all offspring of Pink Fir Apple.

I was excited to find a seed ball on Russet Burbank this summer. I know it occasionally forms seed balls, mostly under laboratory conditions, but I guess we had the perfect conditions this summer! This is rare. Either that, or what was sold to me as Russet Burbank is actually something else; always possible. It did form only the one berry though, in spite of profuse flowering. It is either self fertilized, or fertilized by All Blue, which is a bit of a bummer. However! Shall procede.

I also got a berry off of German Butterball which is much less surprising. My experience with that one is that it produces buckets of berries. Not this year though; just a couple. Still, it is such a great potato I am curious to see what sort of offspring it will have. I didn't grow out any seeds last time I planted it, and got those buckets of seeds, due to lack of space mostly. It is also either selfed or fertilized by All Blue, but the odds of it being selfed go up as it was a fair distance away from the others.

farmermike, you have some interesting looking potatoes there. I too am impressed by that long pink one. Looks like you have a bunch of blues too.

[billw]

Jan 30, 2018 21:19:01 GMT -5 farmermike said:

Got lots of new TPS (including some diploids) in trades this year that I'm really excited to try out. I can usually start planting potatoes out in February in my mild climate, so I think I will be starting some TPS soon. If I get them planted early, they can grow mostly on the winter/spring rains and I won't have to water.

I realized that, in order to grow my own TPS, I may have to grow them during the long days of summer to get them to flower. Does that sound right?

When I grow them in late winter/early spring, and harvest when they dry down in June, I never get flowers. Last summer, I grew an unknown purple potato during mid-summer (with lots of irrigation) and it flowered profusely. It still didn't set any berries though. It seemed to be producing plenty of pollen. Was it likely self-incompatible?

Potatoes will flower at any time of year. Temperature is much more important than day length. Daytime temps need to be between about 50 and 75F to get much flowering. They will flower more profusely during long days, but mostly just because they are taking in more energy.

Unless you have a good reason to think that it is diploid, your purple is probably not self-incompatible, but male sterile. The majority of commercial types and varieties descended from them are male sterile. It could also simply be a flower dropper, which is true of many varieties, particularly if the weather isn't just right.

[billw]

Feb 1, 2018 8:40:18 GMT -5 ferdzy said:

I was excited to find a seed ball on Russet Burbank this summer. I know it occasionally forms seed balls, mostly under laboratory conditions, but I guess we had the perfect conditions this summer! This is rare. Either that, or what was sold to me as Russet Burbank is actually something else; always possible. It did form only the one berry though, in spite of profuse flowering. It is either self fertilized, or fertilized by All Blue, which is a bit of a bummer. However! Shall procede.

Burbank is male sterile, so it would have been pollinated by another variety. That's good though, because Burbank is a pretty poor variety for everything but tuber size. They only grow it successfully with tons of pesticide to keep disease at bay. Much better to cross it and mix things up a bit.

[farmermike]

Thanks for all the helpful information! I found a photo of the potato flower I mentioned.


Is there any visual cue that a potato flower is male sterile? (I've gotten pretty good at recognizing CMS in carrots and brassicas.) I can't remember if I actually checked for pollen release on this one. It was 90F the day this photo was taken on July 12th, and highs the next few weeks ranged from 82-103F (28-40C). Historical Weather

This plants kept blooming and producing new flowers until there were 8-10 blooms on this inflorescence. The flowers never dropped, and just hung on the plant and faded to white. Eventually, the plants looked pretty spent, so I stopped watering, waited for the foliage to die down and harvested the tubers. I'm pretty sure this one originally came out of the "red, white, & blue mix" from Home Depot a few years ago.

The potatoes that I grow earlier in the season, when the weather is cooler, often develop flower buds but they always drop before opening.

[billw]

There is no way to tell by looking at it. In some cases, you can see that a flower has shriveled, poorly developed stamens and those rarely produce much pollen, but male sterility in potatoes is more about producing non-viable pollen than simply not producing pollen. That said, there are probably very few or no varieties that set berries at 90 degrees. That weather is just too hot for potatoes to make seed.

[ferdzy]

Thanks for that, billw. I'll assume we'll see some blue potatoes then!

[jocelyn]

Ferdzy, you probably will, grin.

Last year and the year before I harvested the yellow patch seeds before the others and kept them seperate. I did get some blue seedlings....the tiny tubers are in the fridge right now.
Also, chance mixups where mice or squirrels transport and drop a berry are less likely with blue seedballs. Blues have darker purple/blue/black markings on the berries that the yellows don't get.....not here anyway.

[troppo]

I'm looking play around with Diploids this year to hopefully get some TPS. I was wondering is Mayan Gold a diploid potato? I was kinda hoping to use it as a parent line given its a commercial variety and has the potential to incorporate some of its good traits into some other diploid lines, if it is indeed diploid?

[billw]

Mayan Gold is diploid, of phureja background.

[Joseph Lofthouse]

Potato tubers overwinter in my garden about 3 years in 4.

[richardw]

toomanyirons you say-

In other words, selecting stock for planting based on important traits such as promiscuous pollination, true seed production, yield, flavor, texture, disease resistance, general hardiness, etc. all take a back seat and mean absolutely nothing if the tubers do not keep well in storage until the next year's planting time.

Do you mean not keep well as is spouting or rotting ?
My main potato is Moie moie, it spouts like any other spud when the weather warms, but it never grows long shoots and only gets to about 40cm and stops, ive seen them late spring where they haven't grown any longer in two months. And as for eating once the shoots are rubbed off early spring we can be still eating them nearly up to when the new crop is ready.