Peronosclerospora Sorghi - Importance

Importance

Sorghum bicolor is one of the most important cereal crops around the world, ranking fifth in production behind corn, rice, wheat, and barley. A significant proportion is grown in developing countries in tropical and subtropical regions, where it is a staple for both human and animal consumption, as opposed to in the United States where it is overwhelmingly used for animal feed. In many of the areas where sorghum is a staple crop, in Africa, Asia, and Latin America, access to agricultural technology is poor and yields are low as a result. This makes control of sorghum downy mildew especially important, as infections can dramatically reduce yield further.

Peronosclerospora sorghi causes the most significant yield reduction in corn and sorghum when plants are infected systemically. Models from the United States have demonstrated a direct relationship between incidence of systemic infection and yield loss. Sorghum downy mildew has been reported in 44 countries. It is endemic in many parts of sub-Saharan Africa, where it causes severe reductions in corn and sorghum yield. In corn, losses due to the disease are estimated to range from 15-20% in Uganda, and epidemics have caused losses from 10 to 100% in Zaire.