Pearl millet smut

The disease known as Pearl millet smut is caused by the fungus Tolyposporium penicillariae. This basidiomycete pathogen specifically targets the floral parts of the host plant, disrupting the normal grain-filling process and replacing healthy seeds with dark, spore-filled sacs known as sori.

The primary host for this fungus is pearl millet (Pennisetum glaucum). The disease is widely prevalent in major millet-growing regions, particularly in parts of Africa and India. In these areas, the environmental conditions often align with the pathogen's requirements for infection, leading to significant agricultural challenges.

Symptoms become visible during the grain-filling stage. Infected florets develop into elongated, sac-like structures that protrude from the panicle. These sori contain a powdery mass of teliospores. When the sori rupture, they release these spores into the air, facilitating the spread of the infection to neighboring healthy plants.

Development and spread of the disease are heavily influenced by humidity and temperature. High relative humidity and rainfall during the flowering period are critical factors that promote spore germination and subsequent floral infection. Once the spores are disseminated, they can persist in the soil for several years, serving as a primary inoculum source.

The economic impact of Tolyposporium penicillariae is measured by significant yield losses and reduced grain quality. Control strategies are centered on integrated pest management: using resistant cultivars, implementing strict crop rotation, and applying systemic seed dressings. Proper field sanitation is also essential to reduce the overall spore load in the environment.

• Deployment of smut-resistant pearl millet hybrids.
• Treatment of seeds with recommended systemic fungicides.
• Crop rotation to break the pathogen's life cycle.
• Roguing and destroying infected panicles before sori rupture.