SEX AND THE SINGLE PAWPAW

(One of a series of articles about growing fruit trees in Samoa, written by Digby Gotts and published in the 'Samoa Observer' between December 2000 and April 2001)

This would have to be one of the most well known fruits of the tropics, with many tons passing through the Fugalei markets every week. The many shapes and colours lead to quite a bit of confusion, not helped by another fruit unrelated to papaya also being called pawpaw in the USA. Papaya is the correct name, used in most countries internationally, but local usage calls them papaw or pawpaw and that’s what’s more important.

These fruit grow very easily from seed, but each seed can grow up into male, female or a bisexual tree. Male trees typically are a waste of time and do nothing except pollinate the female flowers causing them to set fruit. Fruit from pure female trees are usually round or smoothly egg shaped, while fruit from bisexual trees are pear shaped (smaller at the top than at the bottom). The colour and size of the fruit can vary enormously, from red through orange to yellow and from the dinky little “Hawaii solo” at 400 gm to the monster “Thai red” at over 5 kg.

Trees grown from seed from pure female trees will be either male or female but there is no way to identify the males until they flower. The females will only set fruit if a male is nearby to provide pollen and the fruit will therefore have a mix of characteristics of both parents. This means that you cannot easily continue a line of favourite tasting fruits if they are pure female.

In hot climates, the bisexual papaya produces a much sweeter fruit and is one to look out for here, but again the seed will not run true to the parent if the flower has been exposed to any other papayas within a mile or so. If you have your own favourite bisexual papaya and want to grow more like it, you will have to put a paper bag around the flower to ensure that it pollinates itself. Keep an eye on the developing fruit to ensure that you remember that this one is for seed and don’t let the kids near it. One third of the seeds will produce pure female trees and two thirds will be bisexual so you can keep the strain going by selecting the best of your bisexual plants for the next generation.

So if you do find a bisexual fruit with excellent flavour in the market, sow all the seed immediately with three seeds in each planting site. As soon as the flowers form, pull out the weak plants and any trees with male flowers, leaving one tree at each site. Once the fruits form and become edible, choose the tree with the best fruit to cover some flowers, forcing a closed pollination and therefore producing seeds which will run true to type for the next generation. In this way maybe one day Samoa will have her own Esi samoa for selling all over the world.