Weeding Out Potato Wart from the Fields

Potato wart is an important and serious disease of cultivated potato (Solanum tuberosum). The disease is caused by the fungus Synchytrium endobioticum, and this organism is considered to be the most important world-wide plant pathogen of cultivated potato. The potato wart pathogen is readily distributed through infested soil and by infected seed tubers.

Resistant potato cultivars have been developed in Europe and North America. Resistant plants may become infected, but symptom development is suppressed. Galls on resistant plants remain scab-like, while in some cultivars zoospores (motile asexual fungal spores) of the pathogen are killed by a hypersensitive reaction of the infected plant tissue. However, the emergence of different types of S. endobioticum types has compromised the efficacy of host plant resistance. In some cases, application of crushed crab shell onto the infested soil has been found to suppress the disease, although the mechanism of action is not yet known with certainty.

Potato wart is much easier to prevent than to control. Worldwide prevention is based on the control of disease spread. Once potato wart is detected, regulations generally prohibit potato production on infested soil, and also attempt to prevent soil movement from infested sites by any means. Examples include prohibiting growth of any plants destined for transplant and requiring a continuous "cover crop" to reduce movement of inoculum via wind-blown soil.

To read more about potato wart, visit http://www.apsnet.org/online/feature/potato/.