Flowers are where we get fruit. Making a flower is a sign of a healthy plant and making lots of flowers is a good sign as to the sort of yield you are going to get. If you have put lots of compost and manure into your soil, your plants should be able to pick up the nutrients that they need.
I thought that I had done that with my tomato plants. Lots of good quality compost as well as some pea straw that had been breaking down in the chicken run. Rain had come through at fairly regular intervals and the plants themselves looked in rude health with lots of leaf growth. I was looking forward to flowers and then not long after fruit. The flowers came through, but then they fell off before they started to set.
The flowers had fallen off just at the point where they joined onto the stem. This was a problem that was occurring on all the tomato plants so I needed to sort it out. So why don’t you get flowers on tomatoes?
The most important trace elements in flower production are calcium and potassium. You need water to transport this where it is needed in the plants. So I made a concoction of lime (about a handful per plant) and potash (half a handful) and mixed that with 5 gallons of water. The lime provides the calcium and the potash provides the potassium. You could put these powders around the base of the tomato plant and then water it in, but I decided to do it all in one hit.
You should try very hard to avoid getting this mix on the leaves of the tomato plants because they will get burnt. What should then happen is that the next batch of tomato flowers will be more vigourous (from the lime) and you should get better and more fruit because of the phosphate from the potash.