Combating Rind Necrosis

Bacterial rind necrosis of watermelon, sometimes referred to as rind necrosis, is a fruit defect and can be a serious problem in watermelon. Incidence and severity can vary widely between fields, production areas, and seasons.

Typical rind necrosis is characterized by a light brown, dry, hard discoloration interspersed with lighter areas. The disease develops in the rind and rarely extends into the flesh of infected melons in the field.

The means of dissemination of the pathogen is not known, nor is the etiology of the disease well understood, but apparently infection is limited to the fruits. This fruit defect appears to be genetically controlled, but its frequency is affected by interaction with the environment. The most resistant cultivars in studies conducted in Florida over a three-year period during the 1970s were Sweet Princess and Jubilee, while the most susceptible were Klondike Blue Ribbon and Louisiana Queen.

For the most part, varieties in use today appear not to be as susceptible as those used in the 1970s, suggesting that watermelon breeders have been successful in selecting against the disease. Since there are usually no external symptoms, a small percentage of diseased melons could make the crop unmarketable, as diseased melons are not easily culled.

As of press time, there are no known control measures.