Q.Every YearbI Grow Watermelons,they Grow, Produce Fruit To Half Size, Then The Plant Wilts And Dies In A Few Days. Why?
This problem does not extend to other curcurbits.

Certified GKH Gardening Expert
There may not be enough nutrients in your soil to sustain growth. I would test pH, and nutrient content. These articles will help:
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/testing-soil.htm
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/soil-ph-plants.htm
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/testing-moisture-in-plants.htm
https://www.gardeningknowhow.com/edible/fruits/watermelon/growing-watermelon.htm