Crazy top with abnormal tassel.
Photograph courtesy Mike BoehmDept Plant Pathology, The Ohio State University, 201 Kottman Hall2021 Coffey Road, Columbus, OH 43210-1087
Host (Latin and common name): Corn (Zea mays)Disease name: Crazy Top of cornPathogen name: Sclerophthora macrospora
Crazy top or downy mildew of corn is caused by the fungus Sclerophthora macrospora. The disease is widespread in the United States and has been reported in many countries around the world. Severe losses are seldom reported. Interestingly, S. macrospora also causes a disease on golf course turf called yellow tuft. Excessive soil moisture, irrigation or flooding is required for the development of both of these diseases. Both diseases are readily diagnosed by the presence of abnormal, excessive or seemingly uncontrolled growth or tillering such as that shown above. Such bizarre growth is believed to be the result of a hormonal imbalance brought about in the plant by the fungus. In the case of crazy top, the fungus survives in soil or in infected plant debris and becomes active with excessive soil moisture. Young plants (4-5 leaf stage) are extremely susceptible. Symptoms are highly variable depending upon many environmental and plant factors. Crazy top is managed through the avoidance of planting in low-lying wet spots or fields prone to flooding and by providing adequate soil drainage.
APS publication number: IW000015
Picture your photograph as the APS Featured
Click here to find out more
License to Copy. This
notice hereby grants permission to APS users to copy the image featured for
noncommercial, personal use. All components of APSnet are copyrighted and may
not be reproduced or distributed except by express permission of APS. Copyright
is not claimed for material provided by United States government employees as
part of their work. APS copyright extends to images, text, graphics,
photographs, illustrations, audio, video, computer software, and all other
elements of the site.Instructions to Copy. For PC, position your mouse
cursor on the featured image, click the right mouse button, and choose "Save
Picture As..." or "Save this Image as..." whichever is the case. For Mac, click
the only mouse button and follow the same steps. Users may want to set up a
specific directory and file naming scheme for storing images; otherwise, they
will be saved using your system defaults. Images may be used in any software
application that supports JPEG file format or viewed in an Internet browser as
Get ALL the Latest Updates for ICPP2018: PLANT HEALTH IN A GLOBAL ECONOMY. Follow APS!