We live in Phuket and i am trying to grow butternut pumpkins and rock melons

I have grown the plants and the are flowering but we get no fruit, i

think its the dew and rain washing the pollen away, has anyone grown

them successfully this time of year or do you have to wait to the end

of the wet season

You may find the flowers are rotting from the humidity or wet conditions especially if the are grown on the ground. If it only a small crop try lifting the the flowers/fruit on the ground with a block of wood, a stone or whatever is available or better still try to grow on a trellis or a above ground mesh so there is airflow around the flower and fruit. This will also help with powdery mildrew as well if that is a problem.

I grew Butternuts and Queenslannd Blue pumpkins in Chiang Mai with some success but only after finding that hand pollination was essential ,

Butternuts are better grown on trellis to avoid ground contact and rot problems.

I grew Butternuts and Queenslannd Blue pumpkins in Chiang Mai with some success but only after finding that hand pollination was essential ,

Butternuts are better grown on trellis to avoid ground contact and rot problems.

yes i know about the hand pollinating i did the same in Australia

i will try the trellis it was not necesary in Autralia