Crown or Foot Rot
Slightly sunken lesions form at the base of the leafstalk. The lesions enlarge and the leafstalk collapses. The stalks may continue to collapse in moist, warm weather until the plant is killed. No chemical control is listed.
Rhubarb Leaf Spot
Symptoms are irregular, circular spots, less than 1/2 inch in diameter. The white spots are surrounded by a red band bordered by light green. The center may fall out giving a shothole effect. No chemical control is listed.