Thomas Schendel

I have actually made the opposite experience: rubber trees really like pollarding! For background: My wife and I bought a former rubber tree plantation, where the rubber trees were felled prior to the land sale. However some of the trees came back to life. After a few years I cutsome of them at a height of ca. 1m. In most cases, the result was a vigorous regrowth. We also have a couple of smaller rubber trees in the roadside ditch, which are cut in a random way at least once per year - they all produce happy regrowth.

Our land has sandy soil and the rubber trees get maximal sunshine - maybe (or maybe not) this can explain our differing experiences.

I guess with strawberry guava you refer to Psidium cattleyanum und by "manage" you may refer to actions that stops this plant to take over the whole property (if I'm mistaken, you should ignore the rest of my reply ). On my land in Thailand (4 rai = 6400 sqm) this specie surely starts to outcompete other plants - its very shade tolerant, grows fast and tall, and the new shaded area of an established tree becomes the breeding ground for at least  another tree and bit by bit this plant conquers more area. Well, in my case (due to the small property size) I simply start cutting the trees. The foliage makes good mulch, and I use the wood for making biochar.

I have seen pictures that strawberry guava forms dense thickets, but this is not the case on my land - they grow as regular trees, which make it easier to deal with them.

Have you considered using sweet potatoes instead of potatoes?
At least they can make delicious french fries and are much better adapted to to the tropical climate.