Gabe15

It would be possible if you brought in a plant from a place where it is present (Most of Asia, large parts of the Pacific including Hawaii, East Africa, some other places too), and the plant was already infected. If some of the aphids were also present on that plant, they could move it to other nearby plants in greenhouse setting, however it would be extraordinarily unlikely for the plants to just acquire it randomly. The disease depends on an ecosystem to support it, one that cannot be sustained in a place like the UK, so all things being equal that chances of getting it are close to zero, but with people shipping plants all over the world, it's not out of the question to receive an infected plant (the phytosanitary certifications that come with mailed plants really don't mean much of anything), but it will be very easy to control in a case like that, just kill the infected plant and you can pretty much stomp it out quickly and easily.

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Growing bananas in Colorado, Washington, Hawaii since 2004. Commercial banana farmer, 200+ varieties.