Downy mildew of Sorghum

Peronosclerospora sorghi is a plant pathogenic fungus that causes a disease known as "downy mildew" in sorghum (Sorghum bicolor) and, to a lesser extent, other grass crops. Downy mildew is a significant disease that can lead to yield losses in sorghum, which is an important cereal crop worldwide. Here is some information about Peronosclerospora sorghi and its impact:

Disease and Symptoms:

• Downy mildew caused by Peronosclerospora sorghi primarily affects sorghum plants.
• Symptoms of downy mildew in sorghum include pale green to yellow lesions on the upper side of leaves and a purplish gray to blackish fungal growth on the lower side, which gives the disease its name.
• As the disease progresses, leaves may become necrotic, and infected plants may exhibit stunted growth.

Lifecycle:

• The fungus has a complex lifecycle, involving both sexual and asexual stages.
• Sporangia (asexual spores) are produced on the undersides of leaves and can be dispersed by wind and rain, contributing to the spread of the disease.

Impact:

• Downy mildew caused by Peronosclerospora sorghi can lead to yield losses in sorghum crops.
• In severe cases, it can significantly reduce grain quality and overall plant health.
• The disease is of economic importance in regions where sorghum is a staple food and a major agricultural crop.

Management:

• Management strategies for downy mildew in sorghum include planting resistant sorghum varieties, crop rotation, and applying fungicides when necessary.
• Good agricultural practices, such as proper spacing between plants and maintaining field sanitation, can also help reduce the disease's impact.

Controlling downy mildew caused by Peronosclerospora sorghi is essential for maintaining sorghum crop productivity, particularly in regions where sorghum is a vital food and feed source.