Firstly, I found this information in Annette McFarland, Succesful Gardening in Warm Climates on Pg 85 this morning.
'Cucumbers, melons, pumpkins, squash and zucchini...High light intensity can tend to make members of t his family produce large numbers of male flowers, but few females and therefore little fruit. one solution is to grow these plants beneath shade provided by trees and shrubs or just wait until the weather becomes more overcast. Pinching out the runners of plants will tend to make them more bushy and can also encourage production of more female flowers.'
I have a couple of self seeding pumpkins going crazy along my back fence with heaps of male flowers so will try the above advice and see how I go.
Can anyone tell me if they are affected by fruit fly - I noticed a couple of baby fruit last week with glee, but they have since fallen off. I know that insufficient pollination can cause fruit fall, but wonder whether I need to bag them for fruit fly.