Dragon fruit flowers but produces no fruits is one of the most common problems growers face. There are some aspects to look at for this situation. Let's check them out together to see why.
Firstly, you can check if there are some:

Dragon fruit flowers but produces no fruits is one of the most common problems growers face. There are some aspects to look at for this situation. Let's check them out together to see why.
Firstly, you can check if there are some:
Small Branches on Mother Branch
If the main branch carries the load of 5-6 smaller branches, it may be a little too much for it to support. As a result, fruiting may be slowed down.
To focus more energy on matter-most things, prune off some smaller branches. Keep about 1-2 so that main branch has space to extend out, but still retains enough nutrients for fruiting.
This point is for general guideline only. As in some cases, growers have found that their dragon fruit branch can still bear out a good number of fruits with other smaller branches on. Still a point to ponder... and possibly it's each variety specific health? Anyway, take it with a grain of salt as you find out the possible reasons.
As a side note: Locals on some mountainous areas harvest the young shoots. They stir fry them & mix them in various different dishes. It's said to be good for the stomach & tastes like cucumber. You can use the shoots as mulch around the mother tree as well.
Also, do you know what is:
The Age of the Plants
From what we know so far, young flowers may get pollinated but the fruits may not set. One grower we talked to experienced this with his dragon fruit plant. Only in year 3, the plants started to put out fruits. Maybe it's still young.
On the other hand, maybe the branch is too old? Sometimes older branches may have less fertility rates. And therefore, give out fewer flowers & fruits.
Some growers notice the yield for each dragon fruit post. It grows vigorously in the first few years. From year 7 and on, the fruit production levels off at around 60 fruits per plant per year.
So, from year 7-10 it's kind of the plateau point for dragon fruit production. The fruit yield may also gradually decline after this mark. At this point, many growers plant new cuttings or replant the existing branches into new pots (if they're growing them in pots).
This is the dragon fruit yield no