The Northern Territory’s Department of Agriculture and Fisheries confirmed that the fungus Monosporascus cannonballus was found on two farms – a cucumber plant near Darwin and honey‑dew and rock‑melon crops near Katherine.

The pathogen lives in soil and attacks plant roots, causing a rapid form of root rot that can destroy whole crops if it is not treated, according to Chief Plant Health Officer Sally Heaton.

Heaton warned that the disease cannot be eradicated, but the department will cooperate with industry groups to help growers manage the problem. No new biosecurity restrictions are planned, although farmers are urged to keep using existing hygiene measures.

Melons Australia chief executive Johnathon Davey said the incursion is already causing “significant loss” for NT growers and will likely raise production costs.

Higher costs for growers could be passed on to shoppers, making fresh melons and cucumbers more expensive for Australian consumers, the department noted.