I’m growing this in my garden this year! I haven’t done the full harvest yet, but the tubers I’ve dug up to sample were delicious. And it is growing well without even too much water - I planted it among my beans, and it’s making a great groundcover to retain moisture and keep the soil cool. It seems to be growing just fine with the amount of water I normally give the beans.
It’s also extremely high in oil, so it has a big potential as an oilseed crop.
This is something I’ve never heard of, and am going to add to my list immediately!
Look up Joseph Lofthouses’ work with tomato breeding, if you’re not familiar already. The modern “tomato” is just a tiny subset of a tiny subset - the plants that happened to be grown by the particular indigenous people contacted by the spaniards, happened to survive going to Europe and being grown there, and happened to survive being transported to north america and being grown here too. Saying you know what tomatoes are like from trying one of them is like saying you know citrus because you had a key lime pie once. Even the more diverse-seeming heirloom tomatoes still come from this very limited pool.
He’s been working on creating a breeding stock mix with as many wild tomato ancestors mixed in as possible, and the results are crazy. I’ve been growing some of his seeds this year, and some of the tomatoes taste more like tropical fruit than tomato.
Here’s a few of my thoughts on the matter of water usage:
I know it’s probably not achievable, but if we actually want to reduce water usage we’ll need to encourage more small-scale growing and eliminate massive ag monocultures. Sustainable, water-saving techniques and crops are not difficult, they’re just not suitable for mechanized harvests and there therefore ignored.
My vegetable garden needs very little water, to the point that we were away for 4 days during 110F heat and <10% humidity, and nothing was even wilted when we returned. And I’m even growing some corn, which is a notorious water guzzler.
But it took a lot of careful planning, soil prepping, and dense interplanting to reach this stage.
We excavated trenches around the entire edge of the garden bed to a depth of several feet, and filled the bottom half with chunks of logs and large branches before replacing the soil. As these decompose, they act as mini aquifers, and store water that the plants can access. Ever rolled over a rotten log in the forest and noticed how many roots were embedded into the wood? This is why.
We also have a firm “no exposed soil” rule - if it’s not being covered by a plant, it needs to be covered with straw or leaf mulch. Paths are covered in 6 inches or so of woodchips. This helps retain moisture, eliminate soil loss, and prevent weeds.
We also use sunken beds - the planting areas are slightly lower than the surrounding ground, so water pools there and doesn’t run off. Most commercial ag uses raised rows, which are easier to harvest but have horrible runoff problems.
The result? Our 15x20 community garden plot produces far more food than my partner and I could ever use, and we’re constantly giving things away. We grow most of our own spices, including ginger, turmeric, and safflower. We pick about 20 pounds of tomatoes a week, 10 or so in beans, have tree collards with 3-inch-thick trunks, and the corn just hit 15 feet high. And we have an insane population of pollinator insects and birds hanging out all the time as well.
All that just to say, drought-tolerant plants are important but technique is even more so, and current commercial ag strategies are probably not sustainable even with better crops.
But for your list, here’s a few other crop ideas to add:
Caigua - Cyclanthera pedata - it’s a vine that produces small fruit that taste like slightly peppery summer squashes. You can chop them and add them to any vegetable dish when they’re small, or they turn hollow when they’re large and you can stuff them like peppers. Insanely productive, absolutely fine with hot weather, can be planted in terrible soil and doesn’t need much water when established. Also the bees go absolutely nuts for the flowers.
Tamarillo - a perennial solanum, has fruit that tastes like a combo of tomato and bell pepper. It’s frost sensitive, but grows OK in my garden in california. Since it’s a perennial, it needs relatively little care once established, though it does like a bit more water than some of the others.
Mulberries - these grow like weeds, literally. Non-fruiting ones are constantly used for shade trees, but the fruiting ones produce insane quantities of fruit with very little effort. The problem is that they’re fragile and mold quickly, so hard to transport. In places like Turkey they just set up big cauldrons in the orchard and process them on-site into a molasses-like sweetener.
Canna lily - often used as an ornamental, but generally overlooked as a potential food crop. Easy to grow, has big starchy potato-like roots, and looks gorgeous to boot.
Dahlias - most people don’t even know these are edible. Usually bred for looks over taste, but there’s a huge potential food crop there.
There’s also a large number of perennial grasses that could be farmed as grain crops. Once they have established root systems there would be virtually no need to water them at all, because they have roots than can get 10 or 15 feet deep.
Here’s a nice little list of some more underutilized crops:
https://en.wikipedia.org/wiki/Neglected_and_underutilized_crop
and PFAF keeps an enormous database of plants with food crop potential: https://pfaf.org/user/Default.aspx
Sorry for writing a whole novella here, but this is one of my more passionate interests. Given the rise of plant pathogens accompanying global warming, we’re dancing on the edge of disaster by depending so fully on the few crops we use.
According to Smithsonian, "three-quarters of Earth’s food supply draws on just 12 crops and five livestock species.:
https://www.smithsonianmag.com/smart-news/extinction-threatens-foods-we-eat-180965081/
Imagine what happens if we get a global pandemic of a crop disease, and lose one of those species? Yikes.