Why does bitter gourd have many flowers but fruits become small, underdeveloped, premature yellow and deformed size?
Bitter Gourd With Many Flowers but Small Fruits
Certified GKH Gardening Expert
If you are getting plenty of flowers but nothing produces or the fruit that does produce is not up to par, then it is most likely due to poor pollination. Hand pollination often helps. Just use a small paint brush and swirl it around the inside of the flower and repeat on all the flowers on the plant. These articles will help you with attracting more pollinators: https://www.gardeningknowhow.com/garden-how-to/beneficial/insect-pollination-process.htm