Cactus Dry Rot
Phyllosticta concava
Mycosphaerella spp
Please go to our Glossary link at the bottom of the page for explanations of scientific terms
Identification
Small black circular spots develop first, which later increase in size until they reach a diameter of one or two inches. Further advance is checked by the development of callus tissue. Minute fruiting structures are seen in the infected tissue. The disease is in part physiological, influenced chiefly by soil moisture.Prevention
Allow plants to dry thoroughly between waterings.