sentences:  In the case of powdery mildew of carrots yield loss is a very typical result of an infection, as well as the reduction of the ability to mechanically pull carrots from the ground during harvest due to leaf damage(McGrath 2013).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%.