[Maarten]

Hi all,

My wife is Serbian and we have been growing white Serbian pole beans for 5 years now. The first 4 years in Leeds, then 1 year without growing them as we were moving, and then last year here in Birmingham. We were all this time saving seeds at the end of the season for the next year. I had hoped that by keeping seed from the largest pods I would select for the plants most suited to the UK climate. Maybe they did somewhat, but in general the plants look like nothing compared to Runner beans.

Last year we included two other Serbian pole beans to see how they grow and taste; one brown /white marbled and the other black / white. Both grew far more vigorous than the white ones, however, the harvest as measured as grams of beans per plant was the best for the whites. Also the black/white ddn't tast as good. So, I was thinking of an experiment. Crossing the brown/white with the white ones, trying to get better growth in the plants, hopefully followed by a better harvest.

Now the questions is how to do that. I know that beans in general are very efficient in self-pollination and that this already happens before the flowers open. There must be detailed descriptions of the crossing process out there as I assume peas have same issue and these were the favourite subject of the father of modern genetics, Gregor Mendel, and therefore many geneticists after him. I have seen a description somewhere, but it was not clear to me what exactly was being done and at which time of flower development. Is there anyone with experience in bean crossing who is willing to share his/her knowledge?

Thanks,

Maarten

[Yorkie]

Have a look at the Gardeners' World programme from last week on the BBC; there was a sweet pea grower who showed how to cross-pollinate them, and the biology of the flowers is essentially the same as for beans?

http://www.bbc.co.uk/programmes/b03ybpb0

[Maarten]

Thanks for the tip! I regularly watch it but missed this one.

Thanks,

Maarten

[JayG]

I know that beans in general are very efficient in self-pollination and that this already happens before the flowers
open.

French beans readily self-pollinate, runner beans have to be 'tripped', usually by bees, to pollinate.

I believe it can be done manually, but you probably need 3 hands, especially if you are trying to introduce pollen from a different variety. I'm sure Mr. Gurgle will have a description of the process somewhere.

[Maarten]

Hi,

I had a look at the gardener's world episode, which was making it look really easy. I just have in my head that I saw somewhere on Mr. Gurgle (JayG: it took me some time to realise who this was) an explanation including photos that made it look very complicated. What it came down to was that you had to open up a very immature flower as it would otherwise self-pollinate before opening. So, this is either a difference between peas and pole bean development, or the difference between excluding self-pollination completely and trying to reduce it down to acceptable levels.

Thanks a lot,

Maarten

[JayG]

Yes, you have to get to the stamens in the flower before they shed their pollen and therefore bring about the fertilisation you don't want - as you've seen, the sweet pea hybridiser on Gardener's World unwrapped the petals, removed the stamens, inserted the ones he wanted to produce the cross, and then wrapped the flower back up again.

Looks to me like a pretty fiddly operation with any flower, but I dare say it comes with practice (and a very steady hand!) 

(Mr. Gurgle is apologetic - avoiding spelling common trade names correctly when posting is just a habit, and probably a pointless one too!   )

[Maarten]

I'll just give it a go this summer. Plenty of flowers to practise on and I can remove the pollen from a few without pollinating them, which will serve as a negative control as they should not develop seeds if they did not self-pollinate already. After that it will take a few years and back-crossing I guess to get the result I'm after. As long as it is fun, it is worth it.

Thanks,

Maarten

[gobs]

Hi all,

 Is there anyone with experience in bean crossing who is willing to share his/her knowledge?

Thanks,

Maarten

Oh, yes. DD is an expert crosser. He can cross them without all this messing.

Just be mindful, what you get. How do you know, the vigour of the one shall pass onto the other?

Tell us, what you got.