Papaya (Carica papaya) is one of my favourite dessert fruits. It grows easily via the seeds harvested from the fruit. Next to the banana, I believe the papaya is one other fruit tree which many Singaporeans who have land would attempt to grow. It is not difficult to get the tree to grow, but getting it to fruit can be a feat.
I happen to find an article which I find it particularly enlightening. Entitled ‘Why Some Papaya Plants Fail to Fruit’, it is an article written by Chia and Richard from the Department of Tropical Plant and Soil Sciences’ Cooperative Extension Service/CTAHR at the University of Hawaii at Manoa. Click on this link to view the article.
One of the most common problems is when young, developing fruits fail to develop to full maturity which are then aborted from the tree. One of the reasons I can think of is due to waterlogging. Papayas are not tolerant to overly wet soil that is poor in drainage. Another reason that is mentioned in the article by Chia and Richard would be the lack of pollination of female flowers on female papaya plants.
Most of us are aware that papaya plants can either be male or female plants, which produce male and female flowers respectively. There are also plants which produce flowers that have both sexes in one flower and these are termed as hermaphrodites. Look at the picture above (obtained from the article by Chia and Richard) to learn how to distinguish them.
The ovary of the female flower must receive pollen from another plant (either a male or hermaphrodite). When pollinated either by wind or insects, the ovary becomes fertilised and swells up to become the fruit which will have viable seeds. If pollination does not occur, the small, developing fruit is then aborted from the plant. On the other hand, hermaphrodite flowers have both an ovary and stamens bearing pollen. They can pollinate themselves and do not require the presence of another male or hermaphrodite papaya plant.
The hermaphrodite plant is the preferred type of papaya plant for dependable fruit production. Interestingly, commercial growers remove female plantsfrom their fields as soon as the first flowers appear and the sex of the plants can be determined! This is in contrast with what home gardeners do here where the male plants are often pulled out from the ground!
Home gardeners hence should grow several papaya plants to reduce ending up with only one female plant and to ensure the possibility that at least one will be a hermaphrodite with pollen. If space is limited, allow several seedlings to grow to flowering stage in the same planting spot, and then remove all but the healthiest hermaphrodite plant.