passoin fruit not sweet

ED-P starts with ...
27/4/13
My passion fruit vine is a green fruit vine and it has been in for about two years.Each year it grows very vigorously but the fruit is not sweet. This year it grew and grew and only had a few fruit on it and then we had a lot of rain and it went mad and there are flowers and fruit everywhere on it but the fruit are not sweet. Even now at this time of year it is a mass of flowers and fruit but they are not sweet.
What can I do to change this if not for this year but for next year.
ED_P

Jason says...
Depends what kind of passion fruit you are trying to grow but P Edulis is supposed to be sour as anything, that's how it is. It wouldn't work so well on ice cream if it wasn't

rowan says...
Just in case - are you sure that the rootstock hasn't overtaken the graft?
My sister was complaining of the dry and horrible fruit on hers and when I went to check it I had to tell her the bad news. She has now taken it out and replaced it with a non-grafted one.