One Amish boy, however, gets whisked to Venus through a peculiar set of circumstances. Once he wakes up in a spaceship already on the way to Venus, he discovers that the life support systems of the ship are based on one such Amish-raised biosphere. At some point, I need him to identify a disease affecting some plants that the ship's maintenance systems have misdiagnosed. For other story-related reasons, the disease must be directly or indirectly linked to high soil acidity. Additionally, it would be nice if the affected plants belonged to the rainforest biome, but this is optional.
I have tried looking at various plant disease identification handbooks. But these are written primarily for gardeners and do not list rainforest species (at least, those I have been able to find); moreover, they tend to focus on the most common--and therefore easy to identify--plant diseases (whereas, the disease should be sufficiently difficult to identify that it could confuse a sophisticated artificial intelligence system). Searching for "rainforest plant diseases" brings up primarily references to the medicinal properties of rainforest plants, which is not at all what I'm interested in at the moment.
Any help would be greatly appreciated and duly acknowledged in the book when it is published.