I've been delving around looking for pea breeding resources. There are a couple of good demonstration videos on how to physically cross peas. Rebsie's video is great, and I recently found this YouTube resource as well.
A great resource is "Origin, history and genetic improvement of the snap pea" by Myers Baggett and Lamborn in Vol 21 of Plant Breeding Reviews - but this can be a bit hard to find - my library doesn't have access, and I had to go to a Melbourne University Burnley campus library to find it.
Another good paper is "Inheritance of Stringless Pod in Pisum sativum" by Rebecca J. McGee1 and James R. Baggett.
But this video of a recent lecture to an organic grower's' forum in the US, about sugar snap pea breeding is a beauty, at least for the amateur breeder. The sound is pretty questionable, but the information is invaluable, particularly the final slides on back crossing stringless sugar snaps.
I'm particularly interested in the information that Sugar Ann is a stringless variety - great news, since I've got some seed, and even better, seedlings. My purple podded pea project has just taken a new turn - stringless coloured snow peas. The poor productivity of Cascadia in their trials is also of interest - I was going to use this as a new parent for breeding, after tasting them at Annie Smithers restaurant. The restaurant sources much of its supplies from their own edicated market garden in nearby Malmsbury.
So I'm growing out my first F2 purple X snow crosses - and I'm cogitating on how I might apply this new knowledge - will the Sugar Ann flower in time to cross to the purple snow F2s? If I do find a purple snow in these F2s (and that is a bit problematic), should I cross it to Sugar Ann, or perhaps one of the other tasty snows or snaps, or should I wait until the F3? This might be all academic, if I don't get any coloured snows.