Would like to experiment in cross pollination of some beans. Any advice on how to get the best results and how many growing seasons would it ideally take to positively ID a desired result?
Sounds like should go to the search box above and put in "Bean pollination". There's lots to read there but you'll be able to comb thru and get your facts. Good luck!
You might get better answers if you post on the Hybridizing Forum.
Here is a link that might be useful: Hybridizing
Do you want to cross two different varieties? Often times rows planted side by side even 30 inches apart will be cross pollinated by Bumblebees. Bumblebees if you have them are good pollinators. As far as results go it will take two years before you see the results of a bean cross. I don't know why but that's the way bean genetics seem to work. The best marker for finding a bean cross of course will be a change in the seedcoat. Just don't try crossing two beans that are totally of the same color seedcoat as your new hybrid bean will probably have the same color seed. Then you have to be really good at seeing the difference in the plant characteristics. I think another cross pollinating scheme would be to plant two varieties in the same row and alternate planting the seed right down the row. Sometimes the results of a bean cross are pretty interesting. I have had over 100 crossed varieties in my beans back in the 80's and started gardening again recently and found a few more this year. I am a member of Seed Savers Exchange, and about 4 of my crosses have actually have been sold commercially. Check out my website link. With bean crosses there also is the issue of the bean being stable. Sometimes a cross will be frustrating. They keep producing several seedcoat colors when grown every year, and the plants themselves will vary.
Here is a link that might be useful: A Bean Collectors Window