Please post images of at least some of the affected plants.

Sorry no photos, but you would not learn anything more than I have told you.

The variation in effect could be a clue. Does it match the amount of compost used--did they possibly add some fertilizer or other substance that was not completely mixed and burned some plants? Where do they get their compost from? What's in it?

How large is your planting area? Is the damage possibly related to wind currents from an area where herbicides or other harmful substances may have been applied?

Maybe others will have better ideas---

I too am thinking herbicide damage (wind or in the compost or ?), but without pix its a bit tough to diagnose.

tj

Well, images often do "tell" us more than you said, many times emphatically so. The reason is that descriptions -- words -- are interpreted according to each individual's experiences and more.

At this point, I'm guessing herbicide damage, especially because of the comment about curled but don't wilt. But a number of your details don't fit herbicide contamination and/or drift.

Further, I don't know what materials you have in Brazil.

Here, certain herbicides that are used in agriculture and pastures go through the animals intact, then affect garden plants after the manures are applied to the garden.

So images would truly help us help you. Perhaps a friend, relative, neighbor can help you with the digital images.

No herbicide damage. We very rarely use it. This disease has been around for a while, and only this year has it exploded. Possibly because it has been one of the driest on record, though still very humid. I am thinking Panama Disease but the symptoms are not typical. I'm taking samples to our local phytopathology lab on Monday. Keep you posted. - Ian

You don't have to use herbicide to have plant damage.
It can move from elsewhere via air currents and it can be in contaminated organic material.

WHITE SPIDER MITES. Too small to see with the naked eye but clear under the microscope. I am treating with a specific acaricide. Will post results. - Ian.

NOT white spider mites. Despite applying a specific acaricide, many plants continue sick, though not dying quite so quickly. The spider mite infestation may have been secondary as the plants were already weakened by something else. I am now looking into contamination of the water supply. THIS IS A BEAST of a problem.

No water contamination. I have conducted several experiments and come to the conclusion that this is an airborne fungus disease. The symptoms are not typical of verticillium or fusarium wilts and I have ruled them out anyway by sowing seed in sterilized soil. I don't understand the mechanism of this. The spores must enter the plant via the stomata. This might explain why some species which have dwarf forms with very small stomata are resistant but the type species is not (Ixora coccinea) and why it is principally the upper part of the plant that is affected. However, I admit I am out of my depth here. The disease is somewhat on the wane now after we have had some heavy rain, which further supports the airborne fungal disease theory. I'm just hoping it doesn't recur next year, but to be on the safe side I'm going to do all my seed sowing and cuttings preparation early in the season.