Worldwide distribution. In Australia, New Zealand, New Caledonia, Papua New Guinea.
A devasting disease of potato; also affecting tomatoes, eggplants, and others. Entry through roots: leaves rapidly turn yellowish and wilt; stems show browning and ooze from vascular areas; plants collapse and die. Ooze too from ‘eyes’ (buds) of tubers.
Spread: short distances by run-off water; longer distances by movement of infected tubers, soil on machinery, shoes. Possibly insects. Survival: in soil up to 2 years; on volunteers, weeds, roots of non-hosts.
Biosecurity: protocols needed to respond to a breach, and a plan should eradication fail.
Cultural control: use only certified seed; avoid cutting tubers; avoid land where diseases previously occurred, or have 2-3 year (preferably 4) rotation with unrelated crops (cereals, sweet potato, cabbages, onions); improve drainage using ridges or raised beds; rogue disease plants; clean machinery, tools, footwear after working in infested fields; collect debris after harvest and burn.
Chemical control: not appropriate for this disease.