My squash breeding project

Hello, I’m a market gardener in South Carolina. This year I’m starting a squash breeding project by doing a variety trial. I'm going to try to use this thread to post about my goals, varieties, their crosses, and any success I find along the way!

Goals: short and medium-length vine c. moschata that are productive, delicious, and resistant to squash bugs, pickle worms, and mildews.

Varieties: most crosses I'll be making will involve Butterbush. Quick to maturity, short vine, coppery red flesh, delicious, but can't handle heat, pest, or mildew pressure at all. Most of the other varieties come from SE Asia and South and Central America. I expect they'll be vigorous and disease resistant like the few I've grown, but probably slow to mature and having huge vines. I'll post more of them once I have seeds in the ground. Right now my squash patch is just a lot of black plastic in my front yard.

For now I'm growing out a few Butterbush in pots and building my spreadsheet to assess and compare varieties. I'll try to upload some photos if I can. More updates to come in April/May!

Well here we are!
- About 200 squash plants are in the ground
- 26 varieties of winter squash
- Lots of interesting tropical and Asian varieties

I'll post photos and list some of the more interesting varieties once the plants begin to mature.

I've performed some of my first crosses already with the varieties I started in pots! I’m even attempting an interspecific cross (pictured below): c. maxima x c. moschata. I don't think this particular cross will go anywhere, but it'll be an interesting proof of concept. Planning a few more interspecific crosses this summer that could have much more market potential.

Everything is growing fast! I've made a few crosses already for trying out next year.

1. Guatemalan green ayote.

2. Here's an Indonesian butternut-type squash that should get quite large.

3. A Seminole hybrid I made last year. Very healthy foliage and early to set fruit.

4. The mature kabocha with (hopefully) interspecific F1 hybrid seed inside. I'll report back in July.

Well that squash patch really got away from me after my last post. Squash plants succumbed to disease, a groundhog began eating everything in sight, and my dog trampled half the patch trying to get the groundhog. But it recovered, I took care of most of the groundhogs, and harvested close to 2000 lbs of squash last year.

A few favorites:
1. This cross between a Thai Rai Kaw Tok and a Rancho Marques. This plant produced delicious fruit with rock-hard skin and bright orange flesh. Tasted like spiced cider!
2. This Vietnamese pumpkin was extremely productive and disease resistant. Taste was like a typical butternut.
3. Thai Kang Kob. Has such a rich, tangy flavor. To me, it might be the best for pies and quick breads, because it packs the biggest pumpkin flavor punch. Not productive, all the fruit kept dying, but I harvested two.
4. Chinese Tropical Pumpkin. Nutty flavor, decent productivity, great disease resistance. Late maturity though.
5. The largest and latest-maturing of them all, a Puerto Rican Cuello Largo. 21 lbs and a bit over 30 inches long, 150 days to maturity. Flavor and dry matter were pretty meh though.

Thankfully, I was able to hybridize quite a few of these promising varieties, and I'm looking forward to planting a full 1.5 acres of the hybrids and some new varieties this year on some leased land. I'll be selfing or crossing lots of them and hopefully in 2025 I'll be able to begin proper selections of the F2 plants.

In preparation for the coming season, I'm thinking back to the last season. I would characterize the season as a failure. Not because of the plants themselves, but because the weather (constant rain, then 5 weeks of heat and drought), and the poor soil (0% organic matter, compacted clay). About 8 of the 40 varieties gave me a small harvest, and the rest were total failures. So what are my takeaways?

1. F1 hybrids have the best chances of success in the harshest conditions. Whether it was hybrids I made myself outperforming their parents, or most hybrids I purchased outperforming most OP varieties, I could generally see heterosis at work. The hybrids out-competed the weeds best, which allowed them to set more fruit and shrug off damage from insect pests better. Now, a couple open-pollinated varieties also performed as well as the best hybrids, but most of the top varieties were hybrids. And yes, I imagine modern landraces could perform similarly well, but landrace breeding isn't an option for me as a market grower.

2. No-till really hinders squash on poor soil, but it does aid in drought resistance. Squash just don't like bad, compacted soil. Plant growth was 3x more rapid on identical varieties planted in broadforked soil amended with compost. Yet, the no-till squash endured 5 weeks of drought and daily highs in the 90s. The rye mulch (and weed mulch if I'm honest) really helped here.

3. Success seems possible. I was able to cross and save seeds from several promising varieties. These varieties generally come from South/Central America, and southeastern Asia. They exhibited strong resilience, and some had pretty incredible flavor. My grow outs this year will let me know how successful I was in capturing the best genetics.

4. Squash bugs really, really suck. Literally, I suppose. Squash with thinner skin are more vulnerable. The nymphs crowd on the fruit late in the season, meaning my harvest was much smaller than I predicted. Fruit would look fine and then rot on the vine a couple weeks later. I'm hoping the flooding from Helene and this relatively harsh winter will reduce the pest pressure this coming season.

5. I really hope government grants are not permanently frozen. It will be very hard for me to justify spending hours hand-pollinating every plant once I begin F2 growouts. Hoping to get a Southern SARE grant or similar. If I can't I'll be restricted to small growouts each year and slower progress.

If you are a veteran have you looked into the Farmer Veteran Coalition?  They give out grants and micro grants to help vets get started or improve their farm properties... if not something you can use there may be others who are unaware of their existence.   https://farmvetco.org