The Tropical Fruit Forum

Just responding to the question in the topic title. I have good results with Nantes in a subtropical arid climate. It's tough to source many types of seeds in Mexico so I have't tried other varieties.

Just harvested sweet potatoes grown over the summer in a subtropical arid climate. I plant them around June mostly for ground cover and compost greens but they've been very productive this year. This is from about 3 square meters.

This year was the best and strangest in the last 5 years for my mangoes. Last winter seemed very mild. I wondered if lack of cold hours would adversely affect my lychee, but the small sapling produced 7 fruits compared to last year's one. The mangoes started early. I was eating a local (Criollo) variety from one of my tree in mid-May. Best tasting and juiciest they have ever been and the tree was producing new flowers at the same time. There was a lull in early June when I didn't get any ripe fruit then all the trees started producing outstanding quality fruit. Friends and neighbors have also commented on the outstanding year for mangoes in the area (Eastern side of Baja Sur). It has also been a long season with loads of fruit still on the trees. There was a little rain in the fall but the winter was dry although I irrigate my trees. Last year wasn't too good for me, but I've not noticed a biennial trend over other years.

Wow - very informative posts and a lot of hard work you are doing - thanks.
I'm in Mexico and have bought from Las Caņadas. Unfortunately, it takes about 2 weeks for a purchase to reach me because I'm in a somewhat isolated region. Forwarding to you after that would be hard on any product. You could try to contact raulglezruiz who is in Puerto Vallarta and may get things a little faster. I wasn't too impressed with the Las Caņadas packaging either. Everything just wrapped in newspaper so all the plants had dried leaves and stems. I bought the only varieties they were selling - Camote Beauregard which they only sold as a plant and bulbils of what they call 'Papas Voladora' which came as dried up bulbils. Not sure if this is the one you want. If mine survives and you don't find it elsewhere, I can send you some when they are ready.
I've only just begun growing sweet potatoes/yams - until now all from store-bought produce. Some seem much more productive than other but that may be due to the different parts of the garden I planted them in. I'll be comparing them growing in the same area this year. I've also been impressed with the way the plants make good ground cover and spread if you don't put them on a trellis.
I'm a little nervous about those Papas Voladoras as they are considered an invasive plant in many regions. They sound like hard work to control.
Potatoes have been a challenge for me too. Again using store-bought potatoes for seed. This year I bought some of the Las Caņadas Papas Criollo to try. Previously my plants have been fairly large but produced few potatoes and didn't flower very much. Last year I got a reasonable crop but I'm not sure why. I planted them later than usual, in November/December when it is a bit cooler but my soil is also improving each year from the original wasteland it was. Then of course there is the question of variety. I haven't yet figured out how to preserve the potential seed for the next year so don't have any to plant this year.
Here is a 'groundcover' sweet potato I just cleaned up to prepare for this year's planting.

There is some information on composting manures here.. https://www.gardeningknowhow.com/composting/manures/the-benefits-of-manure-in-your-garden.htm
This is a very informative article... https://www.extension.umn.edu/garden/fruit-vegetable/using-manure-and-compost/
I have an endless supply of goat manure but use it sparingly. There is no vegetable matter in it but loads of goat hair. I keep it in a 1.5 cu m bin, regularly moistened but not turned. It barely breaks down in a year. Turning every few days will speed that up but is very labor intensive. It might help if you can get hold of old manure that has been left around in a pile for a few years. A 3 - 5 mm layer of old (composted) manure dug into the soil seems to work. Mostly I add my fresh manure supply at a rate of about 10% by volume to my compost of dried leaves, chipped branches and kitchen waste. That again is in 1.5 cu m bins and gets turned into another bin about once a month. Three turns in my climate and it is ready for the garden although I use older compost for seed beds.
I also add incompletely composted (direct from the farm) manure at a rate of about 2 cups per square meter to the soil I'm preparing for transplantings. Dig it in, water the bed and leave it to rest for about a week before planting anything. Water if it gets dry.
Some people suggest adding lime to speed up composting manure but I haven't found it helps in my case.
It's taken me 4 years of adding 10 - 15 cm of compost per year to soil that I suspect was a cleaned-up old building site and I still get deficiency symptoms in some plants so compost isn't a quick remedy. Micronutrients supplements in response to soil test recommendations and intensive use of vermiculture drainage (gallons per week) seems to be improving things in areas where I've used them.
So far I've cultivated about 10 - 15 cm of compost per year into the soil before planting or sowing seed. I've then mulched around growing plants another 10 - 15 cm when they were big enough. I've also mulched about the same in areas I haven't tilled. I've thrown compost over ground cover and it falls or washes through fairly easily. The ground cover seems to thrive too.
Another plus for compost (even when used as mulch) is the appearance of worms in the soil - endemic to the area, not the red wrigglers I use for vermiculture.
There can be downsides to compost - such as runoff and an inappropriate nutrient mix that can create imbalances with continual heavy use. Soil tests can help identify some of these issues.

Ah, interesting.  What beans do you plant?

I'm still trying to ID them. They were a gift from an aging neighbor who unfortunately died. The closest I've come is 'friholes cuernos' or 'horn bean' which is probably a generic name.
Here they are:

And on the vine:

And the row of vines. There is a dried-up row of black beans in front that are totally dried up. They were in the ground for 3 months whereas the healthy looking row has been in the ground for 6 months and seems to be starting a second life right now. They are supported on a frame but I've just left them on the ground in previous years.

Interesting that tamarind is a challenge to cultivate in San Diego. I'm about 800 miles South in the middle of Baja and they grow like weeds here - from seed, not from invasive roots. It may be a little warmer here with no frost and the heat gets pretty intense in summer. Summers are in the 90s for about 3 months and winters occasionally get into the low 40s.
My trees are quite mature. One is on the edge of my veggie garden which is irrigated daily. The other is in a ~10' diameter bed in the middle of a paved patio and never gets water. The latter is very much the healthier tree. Average rainfall is about 7" with a range of 0 - 24". The trees survived a recent 11-year drought.
I've also noticed that germination of tamarind seed in my veggie patch has declined as I've improved the soil with compost. Maybe they prefer a poorer soil. They are nitrogen-fixers.
If you want to try my seed I'll be flying into LA late July and can try to bring some with me.

It's been a while now but I think I cured a similar stump problem by digging down and cutting off the stump about 12" below the surface.
Another stump was encased in a concrete path which discouraged any digging. I hit the emerging shoots with glyphosphate which took about 6 monsths to kill the stump.

Here is a quote from the Florida IFAS Extension - "In addition, some plants may produce more than one type of flower and exhibit different degrees of male or femaleness. This may be triggered by temperature, changing day length, and soil moisture availability. Female plants produce medium to large round-shaped fruit of good quality and a large seed cavity. Bisexual plants produce small to large elongated fruit of good quality and a smaller seed cavity. Male plants with bisexual flowers may produce a few, elongated, pear-shaped, poor quality fruit."

I've been trying to grow them in fairly sandy ground with plenty of compost. I had the same problem with few and small tubers. Someone who has farmed them in the past told me that the runners shouldn't be allowed to form new roots, so move them around. An alternative is to provide support for the runners to grow up so they stay away from the ground. I tried that this year and have had a much better yield.
You can also propagate them by simply cutting off and planting new shoots. No need for the tubers.

Anyone had dealing with the Greenss Shop based in Veracruz, Mexico?
Seeds at http://thegreensshop.com/tienda/index.php?id_category=12&controller=category&id_lang=1
They advertise an impressive collection of fruit trees shipped internationally.
They also have a Facebook page - https://www.facebook.com/TheGreensshop/

If you compost bin remains cool, you might try adding some worms to it to help digestion and produce a rich soil.