Flowering , fruiting and seed production increases the nutritional demands 2 to 3 times.It needs different fertilizers ,Phosphorous, Potassium and calcium.
The easiest thing one can do to side dress with Espoma , garden tone or plant tone. A 40 pound bag costs about 17 dollars.

I see. I thought that any fruity vege plants need pretty much the same nutrients. I have grown cucumbers pretty well; that's why I don't understand why my bitter melons premature..

Thanks

One of the many possible reasons is stress due to excessive heat.

other causes for lack flowering, flower drop are
excessive heat above 90 degrees.

Lack of bees, lack of pollination.
If fruits are set, premature maturing, failure to attain the proper size, t,or fruit drop with deformity, rotting opposite to the side they are attached

it is the defieincy of the above 3 fertilizers
It is well explained in the book Nourishment home grown
by beddoe and several others

My husband is very good with his bitter melons. Some year they were 14 inches long, but this year, the longest ones were only 8 inches. Why? no rain and heat over 100 degrees in Houston made a huges different to all bitter melons.
This is good year for fruits, but not very big bitter melons.
marie