I planted a passionfruit at least 7-8 years ago and for the first 3-4 years
it produced good quantities of fruit. The last 3-4 years however there is no
fruit at all, although it still flowers. Initially, the leaves were all
quite large but as years go on there are less large leaves and more and more
small leaves. Is there a way to restore vigour and fruit to it? Does it need
a prune, and if so when and how much, or is there another solution?