Those do look like persimmons trees and those are unripened fruits.
The intense and prolonged heat stress and lack of rain is causing excess fruits to drop early.


Christine

Fruit drop in persimmons can also be triggered by excessive fertilization...is the turfgrass within the root zone of the trees fertilized one or more times a year? (A recommended practice for the turf, but perhaps interfering with fruit development for the trees, especially if the fertilizer is heavy in nitrogen, which turf fertilizers usually are.) Excessive bearing (ripening lots of fruit) can also cause fruit trees to self-thin and drop the surplus fruits it cannot support well before they ripen, though in that situation we'd expect that at least a few would have remained to ripen normally. If branch growth is near or exceeding a foot of growth per year, then the plants may be so vigorous that they are directing energy towards canopy growth at the expense of fruiting.

Since you mentioned that the other two trees don't fruit at all, do you know if they are male or female? American Persimmon is dioecious (produces male and female flowers on separate plants), and if any female trees do become self-fruitful and begin to ripen fruits without pollination (called parthenocarpic/parthenocarpy), those fruits will probably fall early because they contain infertile seeds or no seeds. (There might be a couple cultivars of American Persimmon which can fruit normally without pollination, but wild trees usually do not.)

Miri