Tips for growing Soursop in Colombia, SA.
Since there was no obvious question in your post, I assume you would like information on how to grow this plant. This article should be beneficial: https://www.gardeningknowhow.com/edible/fruits/soursop/soursop-tree-care.htm
I have a soursop tree more that 5 years old. There are no fruits, no buds even. Everyday we use to pour water. Sunlight is getting morning to evening without any difficulty.
Sounds like your tree has plenty of sun. Is the soil free draining, are you watering thoroughly, and do you have mulch under the tree? Try a fertilizer with slightly higher phosphorous content. This article has general information: https://www.gardeningknowhow.com/edible/fruits/soursop/soursop-tree-care.htm
I've had two Sour Sop trees for two years which I've kept inside during the winter months and outside during summer months. They are about 5' tall. I've had no problems until this year. This winter I added grow lights above them and they started growing and sprouting like they were on steroids. They are having trouble holding the new growth, the new leaves keep falling off. At every old leave, it looks like a new sprout is coming out.
Sounds like the extra light has them confused. Could be that they are used to going into a bit of dormancy, but the light from the grow lights is signaling that they should grow. Could also be that they don't have enough root structure to support the new leaves, or that they're not getting enough water. I'd try dispensing with the grow lights, and see what happens.
The soursop in my plantation (in Johor, Malaysia) has a good supply (quantity) of fruit but I never get a good fruit (quality). It is always almost crunchy even when it is bruised due to insects attacking it. How can I get a good harvest? Will fertilizing it work? Will wrapping it with brown paper bags work?
This problem may be related to the timing of harvest, since under- and over-ripe soursop fruits have poorer flavor and texture quality. Soursops also may need to ripen after harvest for optimum flavor, as described in the following article: https://www.hort.purdue.edu/newcrop/morton/soursop.html
This article contains information on fertilization and other aspects of soursop care: https://www.gardeningknowhow.com/edible/fruits/soursop/soursop-tree-care.htm
How long does it take for soursop to mature from flower to edible fruits?
Here is an article with information on Soursop Fruit.
https://www.gardeningknowhow.com/edible/fruits/soursop/soursop-tree-care.htm
Growing Soursop tree indoors in zone 6. How large do they get in pots, and what size pot to use? Can this be a successful venture?
I am not sure whether soursops can be grown and produce fruit successfully in pots. Their mature size outdoors is 15-30 feet, and it is difficult to get them to fruit successfully even outdoors. In a pot, it may be possible to keep the tree to a small size by continually pruning it back, but the tree would probably be unhealthy and unlikely to produce fruit.
Yes! Soursops can be grown in pots. I have one grown in a 20 litre water bottle and it took just a little over than two years to start flowering and now has its first fruit. It's the size of a medium apple right now and continues growing everyday. Just make sure it is well irrigated and well fertilized (10-10-10). Mine loves to get her leaves wet, I've noticed too.My tree is only 6 feet tall, just so you know.
My soursop tree has a lot of flowers but it won't bear fruits at all.
This is most likely a pollination problem. Soursops in their native habitat are pollinated by ants, and will be better pollinated if at least two trees are growing nearby. Hand pollination will solve this problem. See these links for how to do it (the first explanation is for the related cherimoya tree, but the advice applies to soursop too):
http://forums.gardenweb.com/discussions/2178045/how-to-cherimoya-pollination
http://forums.gardenweb.com/discussions/2191738/how-to-hand-pollinate-soursopannona-muricata