Tomatoes are primarily self pollinating although cross pollination does happen - it is the exception rather than the rule. I grow mine close and have never experienced cross pollination. I presume the commercial operators bag the flowers before they open. Don't think they need to grow many of each variety as each plant will produce hundreds if not thousands of seeds.

That makes a lot of sense. Thanks

So how do you engineer an intentionally cross-pollinated tomato variety? You can fling flowers of one variety around flowers of the other variety, but if they mostly self-pollinate, how do you identify the crosses? I guess you could manually remove stamens from flowers, and stick stamens from other varieties in them. But you'd have to do that promptly, to avoid self-pollination.

Inquiring minds want to know.

Yes, you rip the whole flower except the pistil before the flower opens, so it can't self pollinate. You wait a day or two for the pistil to be 'mature', add some other pollen.

As for the initial question, I would guess they bag the whole cluster to be sure there's really no accidental cross pollination, but for sure many smaller sellers just leave it to nature and in normal gardens accidental pollination is about 1% so it's an acceptable risk vs work for them.

Pretty fascinating. Real flower surgery. Thanks.

Years ago I saw a photo of a wooden framed box that had window screen attached on all sides and on top but open on the bottom. Thought that I saw it on the SSE site but cannot find it now. It was placed over the entire plant. Not sure what the plant was.

Cindy

Nice article about breeding tomatoes. You need to start by "emasculating" the flowers to render them wholly female. Pull the stamen. http://edis.ifas.ufl.edu/hs1248

https://awkwardbotany.com/tag/insects/page/2/

http://judywise.blogspot.com/2014/08/august-journal-garden-and-paintings.html

For the two links above, be sure to scroll down to see the plants in protective wraps (to prevent cross pollination).

Here's another option for isolating plants for seed saving, though it is rather expensive:

https://www.greenstategardener.com/storm-proof-crop-cage-large/?gdffi=eef1323447374a878aadfc2c2688fbe6&gdfms=97E816EFE29B4B9DB62D8C06BFE3D348&utm_source=google&utm_medium=cpc&adpos=none&scid=scplp2181&sc_intid=2181&gclid=EAIaIQobChMIzq68qYvt2QIViJXICh0aOwoPEAEYASADEgJlxPD_BwE

The growers around here use isolation boxes with the mesh stuff like what cindy posted. In a field of tomatoes I'll see maybe 4-8 plants together in the row shrouded with the mesh through the season.