Sorghum ergot

The causal agent of this disease is the fungus Claviceps africana, a specialized pathogen affecting the inflorescences of sorghum. It belongs to the ergot family and causes significant physiological changes in the reproductive organs of the host plant, preventing normal grain formation.

The primary hosts of this pathogen are commercial sorghum species (Sorghum bicolor). The infection process is strictly dependent on the flowering stage, as the pathogen targets the ovaries of the sorghum florets, hijacking the plant's reproductive resources to produce its own reproductive structures.

The initial symptom of infection is the appearance of "honeydew," a sweet, sticky secretion that accumulates on the panicles. Following this stage, light-colored sclerotia develop, replacing the grain kernels. These structures are distinct from the dark purple-black sclerotia typical of other ergot species.

Favorable conditions for the development and spread of Claviceps africana include moderate temperatures (around 20–25°C) and high humidity. Frequent rainfall during the flowering period significantly increases the rate of spore germination and the efficiency of secondary spread via wind and insects.

The economic impact of sorghum ergot is substantial, as it leads to severe yield losses and grain contamination. The presence of toxic alkaloids in the infected grains poses a major risk to livestock health, rendering contaminated batches unfit for animal feed and strictly limiting marketability.

• Planting of resistant sorghum hybrids.
• Crop rotation practices to break the infection cycle.
• Seed cleaning to remove sclerotia from planting stock.
• Application of targeted fungicides during the early flowering stage.
• Monitoring weather patterns to time chemical control measures effectively.