Acidivorax citrulli is primarily seed transmitted.[5] Seeds containing A. citrulli are difficult to treat, as the bacteria is found deep within the tissue, and can be viable for 35 years or more.[6] There are still some aspects of the epidemiology that are unknown. It has been found that the pathogen initially starts its life as a saprophyte, relying on the seed's degrading action of complex sugars, and switches to a pathogenic growth mode when the seedling emerges.[7] While this is a step forward, there is little knowledge of the pathogen's movement in the plant, how it overwinters, or its alternate hosts. Without this knowledge, its complete mode of reproduction (an important tool in reducing epidemic) is still unknown.
The infection of fruit is better understood. Bacteria typically enter the fruit through their stomata, three to four weeks after fruit set. As the fruit develops, wax fills and blocks stomata, eliminating entry to the bacteria. While the maturation of fruit restricts entry to the bacteria, mature fruits are more susceptible to symptoms of the bacteria than immature fruit. Fruit typically show symptoms in the final weeks of development, leaving a lag period between infection and symptoms. The fruit typically becomes infected early in development, and shows symptoms near harvest, making diagnosis and prevention difficult.[8] The only known way for the bacteria to get into production fields is by introduction of infected seeds. This makes sanitation highly important.