Stressed and injured roots are more susceptible to root infection than healthy roots. Roots are leaky. They are constantly exchanging water, sugars, and gases with the surrounding soil. Injured or burned roots are especially leaky. These roots tend to attract root pathogens because some, like the water molds, can follow a chemical gradient in the water to the injured root.
Wounds also provide a direct entry point for many pathogens.
Some root pathogens, such as Fusarium and Rhizoctonia , are favored by stress conditions including excessive drying and rewetting of the soil medium. Roots subject to these conditions may crack and die. These roots are especially attractive to pathogens because of their leaky nature and direct opening for pathogen entry. Root rot disease prevention begins with proper water management. Often is si a fine line between proper and improper water management, but in general the longer the soil medium stays wet, the greater the likelihood of developing root problems.