Fertile C. moschata × C. pepo

[Klaus Brugger]

This year, I grew several plants of a pumpkin hybrid that is basically 50 % Cucurbita moschata and 50 % C. pepo, arithmetically.

The moschata parent already had some pepo in it (from previous breeding work), apparently faciliating the cross considerably. I did hand pollinations among the sibling plants and had a good fruit set. Fruits seem to have a good number of well-filled seeds.

I'll probably be able to send interspecific F2 seeds to other squash enthusiasts in the EU. I don't really know what to expect from the next generation though. It could probably be a starting point for a stable interspecific cultivar (or just a diverse population). Such a hybrid could also act as a bridge to faciliate the transfer of traits between moschata and pepo, and it could perhaps be a parent for tri-species hybrids with maxima (something I'm playing with a bit, too). Most plants this year had a semi-bush growth habit (from 'Honey Bear' in their pedigree).

[Carol Deppe]

Very attractive looking fruits, Klaus.

In much of the USA one of the big advantages of moschata is that the solid stems make them resistant to vine borer. And solid stems is something you can evaluate early, before flowering. At least I assume so.

Both pepo and max can have genes for true bushes. Moschata doesn't, as far as I know. Moschatas may have short vines. But not really bushes as far as I know. In both pepo and maxima the true bushes produce lots of flowers, and they reflower. That is, if you pick young immature fruits the plant simply makes more flowers and fruits. So a bush pepo or maxima can potentially be a very productive summer squash. But, like other pepo, it has hollow stems.

In my experience the bush maximas are relatively wimpy plants with bush root systems. However, bush pepos can be big vigorous bushes. That plus the associated reflowering are probably the reason why American heirloom summer squash are nearly all bush pepos. However, pepos are usually susceptible to vine borer.

So one possibility of your project is to produce a new summer squash class that has solid vines and true bush type. Don't worry about squash shape. Summer squash can be any shape, including round. However, thick flesh really matters. Some summer squash varieties can make good winter squash too. Some summer squash can also make a delicious winter staple by slicing and drying in summer squash stage. My Goldini Zucchini II was deliberately bred to be a dual purpose summer/drying squash.