Erysiphe heraclei is a plant pathogen that causes powdery mildew on several species including dill, carrot and parsley.

[4] Erysiphe heraclei is no different than your typical powdery mildew as it shares many of the important traits that make it a plant disease worth paying attention too.

[5] The effects of yield lost are felt most with early infections, for carrots there has been a noted difference in disease expression and harshness across growing operations.

In some experimental trials carrots who had no control measures against Erysiphe heraclei experience yield losses of 20%.

The first stage in the disease cycle starts in the spring where the overwintering inoculum become exposed to ideal conditions.

[6] The cleistothecia then releases airborne spores called ascospores into the environment, which will serve as the primary inoculum during the growing season.