project update by
I visited my closest collaborator. Jeff, on this project in the nearby city of Longmont Colorado. He had some citron melon hybrids that were left so we cut them open and did taste tests and attempted to text brix levels. We found 3 or 4 had bright yellow skins that to me looked really interesting, but sadly inside they were white fleshed, medium-firm and bland to no flavor or sweetness at all. Some others were very firm white flesh with bright red seeds and looked the most primitive like pure citron melons. We made a decision to discard the most primitive right away and put them in the compost bin.
(sorry I forgot to take any photos)
We found two that had pink flesh and fairly soft flesh and had some sweetness (about 4%), but one had quite a bitter after taste which was unpleasant and slightly worrying. However the other one was much better and although there seemed to be a hint of bitterness it was not enough to worry either of us and decided that for him we were going to only plant seeds from that melon in a semi-isolated drip irrigation area this summer.
I'm pretty low on my original landrace domestic watermelon seeds, so I gave the rest to Jeff to experiment with and grow out. If I have shared domestic landrace watermelon seed with any of you I would appreciate you grow it out and if possible send some seeds back.
Otherwise I recommend you all get a Brix Refractometer on Amazon. They are cheap and are easy to use. Domestic watermelon can measure up to 14% sugar while pure citron melons seem to measure about 2% (maybe more if you let them sit longer to ripen over several months?). I also recommend you each start selecting against any that are perhaps too firm and bland (especially if they have red seeds). Select for anything that grows really well for you or is very interesting to you. Don't be too discouraged if you find any that seem bitter, you may decide to select against any that may be bitter or decide to push through and see what shakes out in future generations. It's all a balance of not selecting to heavy early on and not selecting at all. We do want to push this in the direction of being edible and tasty while keeping some of the other interesting or useful traits from the citron melon ancestry.
A sub project of this for both the citron melon hybrids and the domestic watermelons is to develop a new or better "winter watermelon". There are a few domestic varieties that are already claimed to be winter storage melons, but they are hard to find and I don't know how well they actually store or taste. Some are touted as being ripe enough to eat when harvested in the fall, but increase in sweetness to their peak on New Years day. That does sound like something very useful.
Please respond each of you how you are progressing with the project. It is hard to keep track of everyone, where they are located, and how long they have been working on this project with me. You can email me directly at keen101 [at] gmail (dot) com. However I would prefer your responses be public so everyone can see each other. Collaborative plant breeding can work best when we are all sharing our success and failures as well as seeds.
Loveland, Colorado, USA