Not all sugar apple varieties are self pollinating. Some do require hand pollination. Of the many sugar apple varieties, 'Na dai Vietnamese' is one that can self pollinate. As sugar apple tree naturally produces a lot of fruits already, hand pollinating is therefore not really intended to increase the fruit set rate. Growers often hand pollinate though to help increase the size of the fruits and their shape.

A weird looking sugar apple | Photo by: Rahul Amin (Pixabay)

A Common Misconception

A sugar apple tree, like those in the same Annona family, doesn't produce separate male and female flowers like those in melon, gourd or sponge gourd. This is one common misconception. It is actually the same flower that has both male and female sex organs (aka hermaphroditic flowers).

The thing is, the flower reaches the male and female phase not at the same time. In this case, it usually develops into female first. And then after about 24 hours, the stigma will dry up and the flower will become a male (maturing male organ part or anthers and producing pollen inside).

As the stigma (female part) and anther (male part) mature at different times, the pollen on the flower won't have time to pollinate the stigma of that same flower before the stigma dries up.

Because of this, the flower has more chances to receive pollen from other sugar apple tree flowers which may have matured sooner; thus, increasing the chance of cross-pollination. The Annona plants evolve to have this sort of flowering mechanism partly because of its prevention against the genetic degradation of self pollination.

So technically and strictly speaking, when doing hand pollination on sugar apple or any Annona in the family, it would be more accurate to say 'to choose flowers for pollen' rather than 'to choose a male flower'. Or 'to choose flowers for pollination' rather than 'to choose a female flower'. Along the same line, a sugar apple flower can both release and accept pollen.

Hand Pollinating Sugar Apple (Annona Squamosa)

To hand pollinate sugar apple, you can prepare a few simple things:

  • Paint brush (or in the wild they use a bird feather)
  • A collecting cup (or simply the outer shell of a nut like macadamia)

To find the pollen, you would look for a flower that is in the male phase. Or simply one that has its three petals open slightly a bit more widespread. It will create a sort of open door where you can look inside and see little anthers with the pollen.

When you've spotted one, you can use a paint brush or your finger to brush off the pollen into the collecting cup. The little brown-gray pieces are the anthers. The whitish yellow dust inside is the pollen.

With the pollen collected, we can begin looking for a flower for pollinating.

To look for a flower that is in a female phase, you'd look for one that has its three petals pointing inwards or more tighter together (like a little shy girl). Look inside to see if the stigma of that flower is still slimy or wet. This suggests that it still has good viability to accept pollen. If the female part (the stigma) looks dry, it may not be a good receiver.

When you've spotted a good-looking stigma, you can use a brush to brush the pollen onto the stigma. The pollen will stick on there. Or in the words of a grower, the sperm-y pollen will swim into the stigma. And we wait for the magic to happen as it comes into fruit formation.

Just to note: Some growers break off a small piece of one petal of the pollinated flower just to mark that it's been pollinated. You could also wrap a colored tie around the branch as a mark.

Avoid breaking too much of the petal or else the pollination may not be successful. Some growers break two petals partly to see the stigma more clearly during hand pollination. The pollen didn't take. The flower turned black and fell off. So keep some petals on to possibly retain the moisture inside (keep the stigma moist) and prevent the wind from blowing the pollen away.

Share or pin this post!

(to be created)

Cover image source