Sesame smut

Sorosporium indicum is a fungal pathogen that causes sesame smut, a devastating disease specifically targeting the sesame plant (Sesamum indicum). As an obligate parasite, it disrupts the reproductive cycle of the host, replacing the seed-bearing tissues with a mass of dark fungal spores, essentially causing total loss of the grain in infected pods.

This disease primarily affects the sesame crop in various tropical and subtropical regions worldwide. Its prevalence is closely linked to the intensity of sesame cultivation, as the pathogen exploits the host's physiological development stages to ensure its own dispersal through the field environment.

The most visible symptoms appear during the pod-filling stage. Instead of developing healthy seeds, the seed pods become swollen and distorted. When these pods rupture, they release a dark, sooty powder consisting of teliospores. These spores are wind-dispersed, leading to secondary infections throughout the field during the growing season.

Environmental conditions, particularly high temperatures and fluctuating humidity levels, are critical for the spread of Sorosporium indicum. The pathogen thrives when these conditions coincide with the flowering stage of the crop. Once established in a field, the spores can survive in the soil for several seasons, creating a persistent risk for subsequent sesame plantings.

The management of sesame smut relies heavily on an integrated approach to minimize crop damage. Key strategies include:

• Using certified disease-free seeds.
• Treating seeds with appropriate systemic fungicides.
• Implementing crop rotation with non-host plants to break the disease cycle.
• Removing and destroying infected plant debris to reduce soil inoculum levels.