There is also a complex selection of horticultural pests and diseases, including the tobacco or sweet potato whitefly, bemisia tabaci and other glasshouse insects, the pepino mosaic virus - which hits tomatoes - potato spindle tuber
viroid and angular leaf spot on strawberries.
A shipment of Maine seed potatoes was prohibited from being planted in New Brunswick, Canada, because it was believed to be infected with potato spindle tuber viroid.
The crux of the matter was what type of test would be used to determine whether or not potato spindle tuber viroid was present.
Another USDA scientist found the first viroid ever identified by scientists when studying potato spindle tuber
disease, which is transmitted in tubers and seed.
In 1971, ARS researchers determined that a viroid was the cause of potato spindle tuber
disease, which previously had been identified as a virus.
At the heart of all this activity is the potato spindle tuber
viroid (PSTVd), which the scientists use in their experiments.
It is able to detect potato spindle tuber
viroid that attacks potato tubers and tomato roots, stems, and leaves.