By 'custard apple', I mean the sugar apple - and not the bigger fruit which is the commercial custard apple that grows in the cooler and wetter areas like the Atherton Tablelands and the southern districts of Queensland. If the reader wishes to be more accurate by erasing my word custard apple to insert 'the sugar apple' that is all right by me of course.
AREAS OF DISTRIBUTION
The custard apple grows best in the hotter and drier and sandier areas of the north e.g. Cardwell, Chillagoe, Almaden, Thursday Island and many other places too. Indeed it grows wild in places like Almaden, Chillagoe, Leadingham Creek off Dimbulah, and, I imagine, on some creek banks of the old mining districts. Generally where the mango is to be found, there the custard apple grows too. Custard apples will grow and fruit in places like Cairns, Mossman etc, but they seem to thrive more in the drier localities.
AREA OF WRITER'S COMPETENCE
These are merely personal and practical observations after 20 years in North Queensland in various areas, of watching the custard apple grow as well as intermittently growing them, depending on where I was stationed as the Catholic Priest that I am. I have read nothing of substance on the fruit, nor talked to anyone with much experience or interest or economic success in the growing and selling of custard apples. But I am sure that there is an opening for somebody, somewhere, to do well with this small crop and the marketing of the backyard custard apple.
IN THIS FRUIT THERE ARE TWO CLOSE VARIETIES
After a while, I found that I liked to eat some custard apples better than others. Then I discovered that there are two varieties. I will call them type A and type B. Type A is the greener of the two, while type B when ripe, is a bluer colour. Type A is more rugged in contour appearance when it is ripe. The ridges and valleys are more pronounced; while type B when it is ripe, is more smooth-looking and levelled out. Type B is more custardy and liquid and sweeter. I, personally, like type A the best. Type A is the main type in Weipa, Thursday Island (and Cardwell, I suspect). 60% of the custard apples in Almaden-Chillagoe are type B. It is only when they are in the last 5 days that I can tell the difference. The trees seem to be identical. I imagine type A would carry better and be the type to pursue.
THE PLANT IN THE FIRST SIX MONTHS
The seed often takes four to six weeks to germinate. I am sure the process could be speeded up, but I was never in the position to ask anyone how, nor was there any need for it in my situations. They grow better if they are transplanted quickly as a seedling, in the first two or three weeks. They do not seem to like the root disturbance that comes with transplanting at a few months further on.
Certainly, the further north one goes up Cape York, the plants in the first six months of life do better with only half a day's sun on them, even less. Some sort of shading seems almost essential, my experience anyway. One of the interesting things about the custard apple growing naturally in a backyard or somebody' s property, is how the tree hugs the side of buildings and sheds, whether that is where the bird dropped the seed, or that is where water has been available, or that is where shelter from sun and wind has occurred.
If the soil is helped along carefully with manure or a little fertilising with plenty of watering, the plant will grow very fast between September and April. It is one plant that is helped very much by having a mulch or lawn clippings kept damp around the tree. The young, healthy plant can first flower at eight weeks and have its first fruit at six months. They like cow and fowl manure. Some plants are like many a mango tree which grows with only one central branch. This should be pruned into several branches at six months or so.
SOME PATTERNS OF GROWTH
The plant goes into hibernation to some extent in winter - the more so where there is a real winter. Springtime brings new leaves and then the flowers, which mature into fruit by February, March April. Trees will fruit into July, August, but in places like Mareeba and Dimbulah where there is a winter, the few fruit can stay on the tree and not ripen. Whereas in Thursday Island when it is hot and humid, the fruit could split on the tree just a few days before ripening. I have not seen that elsewhere. There are trees in Weipa that bear good fruit all the year round. Probably Thursday Island and many cattle stations would do the same if the trees were watered.
Some sort of constant pruning over the years is vital. This is an expertise I have not yet acquired. I have never lived beside the same tree long enough to see what happens to a tree as the years roll on. Certainly any dead wood should be drastically cut off. I suspect that there is a need and a skill in pruning a tree - after every two years or every five years? I do not know much about that, but experience and the wisdom of others would teach you that. I have been told that in pruning the older tree, say after years of nothing having been done to it, instead of pruning it all back to the stump, it is better to leave one main branch as is, and prune the others, and then prune the other branch the year after. I used to wonder what would happen if someone with a chain saw went up to the old trees around the deserted Lappa Junction Hotel near Petford and pruned them. Would fruit production occur again or are the trees just too old?
There is a scale of a brown-golden colour which can form on the trunk of the young tree. I am sure most readers would know the name of it and how to treat it. I have had success by just cutting back the tree to below where the scale had started. Then sometimes the backsides of the leaves can get the white mealy bug. This can be wiped off with a mixture of methylated spirits and water. Then there is the disease which makes the fruit go black. I do not know if this is more endemic to some districts than others or whether it is the result of a wetter climate or lack of pruning. Most trees in the Dimbulah area seem to be affected by this. It was very rarely seen on the trees in my time on Thursday Island. It seems to me to be largely the result of when trees are just not cared for. The remedy for me has been to cut off diseased black fruit of past seasons, prune any dead wood, put some care into the tree over the next twelve months, say a prayer and it just did not seem to occur the next fruit-bearing season.
ACCEPTANCE OF FRUIT
It seems to me that people either like the fruit very much or they are not interested in it at all. I suspect that a lot of northern residents have noticed it or tasted it. Some people see the backyard custard apple like eating crab, "not worth the trouble", spitting out the seeds. On the whole it seems to me that folk of the Anglo Saxon races like the custard apple much more than people of Mediterranean descent. I do not know how our new Asian tourists would go for this fruit. From the commercial point of view, the fruit ripens very fast, bruises easily, so a certain speed would have to happen in picking, packing, transporting, selling and getting them in good condition to the consumer's home. It almost seems that sales would have to be relegated to the markets system of the Saturday morning. So many people of my acquaintance are so fond of this fruit, it is a shame it is not more readily available.
DATE: September 1989
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