Encouraging flower and tps formation in potatoes that don't normally flower

[Galina]

On Facebook on the pages of the Kenosha Potato Project a very interesting discussion started on 29.5. at 13.22 by Sam Jones. They are talking about suspended tuber growing. The tuber starts being grown like normal and produces roots and shoots. Then the tuber is unearthed. Roots are growing in growth medium below the tuber, the tuber is open to the sun, any stolons (that would produce potato tubers) are removed. The plant has no choice but put all energy into top growth and because it cannot reproduce by cloning itself, it is thought that this will stimulate flower formation. All plants want to reproduce and shy flowering potatoes can be made to flower this way.

This is the theory anyway and it will be interesting to see how successful this is. Maybe it has been done with good success before (does anyboy know?).

Unfortunately this does nothing to explain why my Picasso potato produced berries (as I did get tubers too), but it is a fascinating method and hopefully will be very successful.

The other way of encouraging flower and tps production as has been mentioned by a member on here before, is grafting potato plants onto tomato rootstock. In the case above on fb, the author attempted to graft, but his grafts had not been very successful.

It would be fabulous to get more potatoes to reproduce sexually. Ultimately it would also be cheaper to breed new and similar varieties from tps rather than in vitro storage and virus cleaning for old varieties that are heavily virus loaded.

[Galina]

Maybe I should have said that we do need both virus cleaning and new breeding, because we do want to prolong the life of old and good varieties. But breeding has been limited as many European potatoes are non-flowering and therefore not suited to conventional breeding. It was an eye-opener to see that most of our 'classic' potatoes go back to just two or three varieties. Amateur breeding is new, but the successes of the likes of Snookie and Hotdog and others recently have been so convincing. The old theory that any potato berries are useless needs rethinking.

It may be that a commercial potato grower could see the difference in yield etc between say Snookie and a commercial type. I certainly can't and if my pathetic yield of bought Charlotte seed tubers last year is anything to go by (compared to the much better yield of the Jayb bred varieties grown under the same conditions),then what's not to like about potatoes from tps! With better techniques on getting tps a whole new door has opened for amateur gardeners!

[Silverleaf]

I'd have tried potato breeding years ago if I'd realised how easy it was - I mean, you don't even have to cross anything to get brand new varieties!

And I definitely think that there's enormous value in developing our own "amateur" varieties better suited to small-scale growing than the boring old supermarket types. Who cares if the yield isn't quite so good as the commercial ones if we can get bold colours, lots of beautiful flowers, disease/pest resistance and better taste?

My twelve varieties from last year's TPS project are growing beautifully and certainly don't look any different to my commercial tubers in terms of vigor. And I'm excited to see how the yield compares - Aimée did really well in its first generation last year despite tight spacing and not being fed, for example - if I get a decent amount of tubers then why not stick with my own varieties in future?

[Galina]

.Aimee here is a good looking plant. Don't think they will be particularly early, but oh yes! - I am looking forward to seeing the tubers and sampling them. Desire is a favourite of old and has always been our 'go-to variety' when our own potatoes had run out and we needed to buy some.

[Silverleaf]

Here's what Aimée produced for me last year, from TPS, with no food and tight spacing. The paper is printed with a 1cm grid for scale. 41 tubers.

Yes, I like Desirée as well, it's a good all-rounder and tastes nice. Hopefully its children will be just as good or even better!

[Galina]

Have just dug up my lovely Aimees. Very clean, large tubers, a nice looking potato. The haulms were just about withered so it was time for a peek. Nice one, Silverleaf.

[Galina]

Another interesting snippet from the Kenosha potato project on facebook. From William Whitson on 7 August at 22:17. Thread started 28 June 16 on the subject of the Ozette potato. (Is there a better way of referencing FB messages)?. William takes cuttings just as the flower buds emerge and in his experience he gets better berry set on these cuttings than on the plants. He hand pollinates with mixed pollen. A useful technique for flowering potatoes that have a tendency to drop their berries before they are mature.

Maybe Jayb's way of keeping blight threatened potato berries off the plant in a vase and this method have in common that better shelter and better watering than on the main plant open to the elements help with berry development.

Certainly one of the biggest factors is reduced fertility in so many potatoes. Hand pollinating with known fertile pollen or with mixed pollen gathered from other flowers is usually the way to go.

Rebsie Fairholm writes that some potato varieties have a harder time because their styles are long. This means they are a long way from the anthers, stand less of a chance of being pollinated by themselves and need a helping hand for this reason. Is this why I got a (still small) berry on the Sarpo Mira where legs brush past on the path? A bit of flower 'jiggling'? Jiggling certainly makes a big difference with Litchi tomato in the greenhouse that don't set readily.

[Galina]

Aimee had developed a few spots of blight so I dug them up. A few large tubers but many smaller ones too. Must remember to plant these really early to give them the longest growing time possible. Tubers again very nice looking. Will happily continue with these.

I have many flowers but not a single berry so far. Just one of those years. But as I have so many experimental potatoes to follow up anyway, I am not too upset by this. The volunteer Palest Pink Eye is flowering both the volunteer plant and the intended plants, not all of them but some, but no berries so far. We had very strong winds that knocked many flowers off here over the last week.

[jayb]

Wind makes a huge difference in my view, can strip young berries off the plant, just when you think they are doing well and growing on nicely! Hand pollinating makes a big difference to flowers setting.