Kelpwilt was the name given to a fungal infection which, in 2045, began to spread and infect a number of kelp farms across the South Pacific Ocean. It was resistant to all known treatments, and kelp farmers were forced to slash and burn large segments of their crops in order to halt the spread of the disease.
Later that year, agronomist Yoshi Nakamura presented an anti-fungal agent he called "Sorahlaze", which eliminated the kelpwilt within one season, and averted what could have been a global hunger crisis. (TOS novel: Strangers from the Sky)