Last year I tried hand pollinating by removing the petals and everything but the pistil of some of the perfect tomato flowers and then applied pollen from others. Didn’t get any successful fruits. I did it in the morning and it may have been a hot dry period (I tend to underwater). I looked for flowers that appeared to be just coming out of a bud-like shine but I may have timed it wrong.
I guess the question is when exactly does pollination take place and are there clear markers for right before and right after? I would guess that the first pollen is the winner in most cases. Does have anyone have tricks for how to best encourage tomato crossing? I do have some of the open flower varieties and will continue to work with those.
What about this idea: remove a few petals from the tops of random tomato flowers around the garden to encourage pollinators and let nature take its course, saving those fruits? Is that likely to be somewhat closer to 50/50 or is the balance still strongly in favor of the perfect flower since it has its own abundance of pollen?
I had the same problem when I started. Had 5% success rate if i remember correctly. Then I changed so that I do pollination on a later date, usually 2 days after emasculation, sometimes 3. Last year had well over 50% success rate. Probably have become better at judging when the flower is ready to emasculate. Also I try to use first 2 flowers in the truss as those are likeliest to develop. Smaller varieties can use others also. Bigger varieties might not have many fruits per truss and thus anything beyond second flower is risking that it doesn’t want to carry that many fruits. Also the earlier trusses are the most likely to carry fruits in plants that are bush type or grown as bush. At some point plant will have enough fruits that it will abort all others. In some bigger varieties that might be less than 10 fruits. Even if there are more, the rate of holding might go closer to zero than 100% on later flowers.
I do find better success if I can redip pollen several days in a row with emasculated crosses. This is rare for me since I tend to only visit my garden on the weekend.
I found initial success clear back in 2017 with adding pollen to exserted stigma tomatoes. It really varies a lot depending on a number of variables including the weather. Using potato leaf mothers or even potato leaf rugose dwarf mothers gives seedling tells. Choosing a mother with a sturdy beefsteak style stigma can also work well. Making crosses works best for me in a protected environment. Inside the house, inside the greenhouse, in the protected shady backyard. However, even in the open field I had more success last year than before- I started early and made lots of attempts. Weather matters- the flip just switched to highs in the 90s here and I suspect that may lead to less crossing success.